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Binaural-Beat Induced Theta EEG Activity and Hypnotic Susceptibility

Brian Brady
Northern Arizona University
May 1997

ABSTRACT

Six participants varying in degree of hypnotizability (two lows, two mediums, and two highs) were exposed to three sessions of a binaural-beat sound stimulation protocol designed to enhance theta brainwave activity. The Stanford Hypnotic Susceptibility Scale, Form C (SHSS:C) was used for pre and post-stimulus measures of hypnotic susceptibility. Time-series analysis was used to evaluate anterior theta activity in response to binaural-beat sound stimulation over baseline and stimulus sessions. A protocol designed to increase anterior theta activity resulted in a significant increase in theta measures (% activity) between pre-stimulus baseline and stimulus observations for five of six participants. Hypnotic susceptibility levels remained stable in the high-susceptible group, and increased moderately in the low and medium susceptible groups.

INTRODUCTION

Differential individual response to hypnosis, has, captured the attention of hypnosis practitioners and researchers since the time of Mesmer, in the late 18th century. Despite the long recognized importance of individual variation in hypnotizability, efforts to modify or increase individual hypnotic susceptibility have proven to be problematic and controversial.

Part of the difficulty in addressing the nature of hypnotizability has been the lack of consensus regarding the basic phenomena of hypnosis. The central issue has been whether observed hypnotic responses are due to an altered stated of consciousness or merely the product of psychosocial factors.

Considering hypnosis as either an altered state or as a purely psychosocial phenomenon served to provide two opposing factions into which most theories of hypnosis could be grouped. Contemporary hypnosis researchers tend to hold less extreme positions, realizing the benefit of a perspective which is comprised of the strengths of both the special-process (i.e., altered state of consciousness) and the social-psychological theoretical domains.

Theoretical Perspectives of Hypnosis

The 1960’s witnessed the advent of standardized hypnotic susceptibility measurements. Reliable standardized instruments have been developed for use with groups and individuals. Early work with the electroencephalogram (EEG) designed to identify hypnotic susceptibility also began around this time. More recent EEG / hypnosis research has focused on electrocortical correlates of both the state of, and differential individual response to, hypnosis. The concept of a reliable electrocortical correlate of hypnotic susceptibility draws attention to the recent applications of neurofeedback therapy, which has employed a number of protocols designed for individual brainwave modification. Recent advances in the application of binaural-beat technology and the associated EEG frequency following response, which can be either relaxing or stimulating, have demonstrated efficacy of brainwave modification in areas such as enriched learning, improved sleep, and relaxation (Atwater, 1997). In consideration of recent EEG / hypnosis research along with the recently demonstrated efficacy of EEG neurofeedback training research and the binaural-beat technology applications, it would seem that the lingering question of hypnotizability modification can now be addressed by utilizing brainwave modification within a systematic protocol.

As mentioned earlier, it has often been the case in the past to view the field of hypnosis as being dominated, theoretically, by two opposing camps; the special-process and the social-psychological. In general, the special-process view holds that hypnosis induces a unique state of consciousness; whereas, the social-psychological view maintains that hypnosis is not a distinct physiological state.

Popular authors of the post-Mesmeric period (i.e., mid 19th century), such as James Braid, proposed psychophysiological and sometimes neurophysiological explanations for the hypnotic phenomenon (Sabourin, 1982). In fact, Braid adopted the term “neuro-hypnology” to describe the phenomenon and is credited as the originator of the term “hypnosis” (Bates, 1994, p. 27). The work of other English physicians, such as John Elliotson and James Esdaile, on surgical anesthesia and clinical pain relief in the mid-19th century (Soskis, 1986), are indicative of the psychophysiological zeitgeist of hypnosis in that time. This physiologically-oriented perspective is reflected in Hilgard’s neodissociation model (Hilgard, 1986), which suggests that hypnosis involves the activation of hierarchically arranged subsystems of cognitive control. This dissociation of consciousness is clearly manifested in the realm of hypnotically induced analgesia. Hilgard’s conception of a “hidden observer” (Hilgard, 1973) as a dissociated part of consciousness, a part that is always aware of nonexperienced pain and can be communicative with the therapist, is exemplified in his description of a hypnotically analgesic individual whose hand and arm were immersed in circulating ice water as follows:

All the while that she was insisting verbally that she felt no pain in hypnotic analgesia, the dissociated part of herself was reporting through automatic writing that she felt the pain just as in the normal nonhypnotic state. (p. 398)

In Hilgard’s model, the hidden observer is the communication of the above described subsystem not available to consciousness during hypnosis. It is reasonable to assume, considering hypnosis research with pain control, that such a dissociative effect of cognitive functioning (i.e., cortical inhibition) would have, as a substrate, some neuropsychophysiological correlate.

Often the social-psychological or social-learning position sees hypnotic behaviors as other complex social behaviors, the result of such factors as ability, attitude, belief, expectancy, attribution, and interpretation of the situation (Krisch & Lynn, 1995). The influence of such variables as learning history and environmental influences are described by Barber (1969). In this influential discourse, Barber presents a framework in which hypnotic responding is related to antecedent stimuli, such as expectations, motivation, definition of the situation, and the experimenter-subject relationship. Diamond (1989) proposed a variation of the social-psychological view which emphasized the cognitive functions associated with the experience of hypnosis, as described in the following:

It may be most fruitful to think of hypnotizability as a set of cognitive skills rather than a stable trait. Thus, it is conceivable that the so called “insusceptibe” or refractory S [subject] is ‘simply less adept at creating, implementing, or utilizing the requisite cognitive skills in hypnotic test situations. Similarly, what makes for a highly responsive or “virtuoso” S may well be precisely the ability or skill to generate those cognitive processes within the context of a unique relationship with a hypnotist. (p. 382)

According to the social-psychological paradigm, an individual’s response to hypnosis is related to a disposition toward hypnosis, expectations, and the use of more effective cognitive strategies, not because the individual possesses a certain level of hypnotic ability. An important implication of the social psychological or social-learning theory is that an individual’s level of hypnotizability can be modified and thus enhanced with systematic strategies to accommodate for individual deficiencies. These two positions can no longer be perceived as a dichotomy, but more accurately as overlapping areas in a Venn diagram. It is not difficult for one to recognize the role of both individual characteristics (i.e., differential neurological activity) and contextual variables (i.e., psychosocial constructs) in measuring and determining the hypnotic response. In other words, the hypnotic response can be viewed as a product of a trance-like state of altered consciousness, which is itself moderated by psychosocial factors such as social influence, personal abilities, and possibly the effects of modification strategies. Such a perspective allows for a more complete investigation of the nature of hypnotic susceptibility by taking into account the relevant issues within each position.

Importance of Individual Differences

In the middle 1960’s the focus on hypnotic research was dominated by a trait, or individual difference, approach. The use of standardized hypnotic susceptibility measurements became common. Most practitioners today tend to view hypnotic susceptibility as a relatively stable characteristic that varies across individuals. This view, and the realization of individual variability in the ability to experience hypnosis, are not new ideas, as Mesmer long ago emphasized the individual’s receptivity to hypnotic process (Laurence & Perry, 1988). Braid, an English physician during the 19th century, described the remarkable differences of different individuals in the degree of susceptibility to the hypnotic experience (Waite, 1960). The importance of within-individual variability in hypnotic susceptibility is also found in Braid’s comments that individuals are affected differently, and that even the same individual could react differently at different times to hypnosis (Waite, 1960). Differential responses to hypnosis were recognized by Freud in his attempts to determine which patients would be the most responsive to hypnotic training. Freud, like others at this time, was unable to identify reliable correlates of hypnotizability. Freud’s frustration is reflected in his observation that “We can never tell in advance whether it VAII be possible to hypnotize a patient or not, and the only way m have of discovering is by the attempt itself’ (Freud, 1966, p. 106). This view is reflected in the methodology of current standardized scales of hypnotizability which use direct measures of hypnotic responses to determine level of hypnotizability.

Differential treatment outcome, associated with individual differences in the way individuals respond to hypnosis, has been observed by practitioners for centuries. Hypnotic susceptibility may also be a relevant factor in the practice of health psychology / behavioral medicine. Bowers (1979) suggested that hypnotic ability is important in the healing or improvement of various somatic disorders. He has also provided evidence that therapeutic outcomes with psychosomatic disorders “re correlated with hypnotic susceptibility, even Men hypnotic procedures were not employed (Bowers, 1982). Significant relationships have been found between hypnotizability and the reduction of chronic pain, chronic facial pain, headaches, and skin disorders (e.g., warts, chronic urticaria, and atopic eczema) with hypnotic techniques (Brown, 1992). Support for the interaction of negative emotions and hypnotic ability as a mediator of symptoms and disease has also been provided by recent research (Wickramasekera, 1979,1994; Wickramasekera, Pope, & Kolm, 1996). A recent article by Ruzyla-Smith, Barabasz, Barabasz & Warner (1995), measuring the effects of hypnosis on the immune response, found significant increases in B-cells and helper T-cells only for the highly hypnotizable participants in the study. This report not only suggests that hypnosis can modify the activity of components of the immune system, but also highlights the importance of individual variability in response to hypnosis.

In terms of modification of hypnotizability, initial hypnotic susceptibility level may be a factor in the resulting degree of modification. In a paper discussing the issue of hypnotizability modification, Perry (1977) presented a number of studies employing a range of less susceptible individuals for modification training. Overall, the attempts to modify hypnotizability were unsuccessful in these studies. Perry suggested that successful modification tends to be more common in medium susceptible individuals. It may be that the medium susceptible individual, having already demonstrated a certain degree of hypnotic ability, possesses the underlying cognitive framework essential to the hypnotic experience. This line of reasoning could explain the differential responses of low susceptible and medium susceptible individuals to hypnotizability modification training. The high susceptible individual could also prove to be less responsive to modification strategies compared to the medium susceptible individual, as a potential exists for a ceiling effect with the high susceptible individual.

Standardized Measures of Hypnotic Susceptibility

The long observed differences in individual response to hypnosis eventually led to the development of the first viable measures of hypnotizability, the Stanford Hypnotic Susceptibility Scale, Forms A and B (SHSS:A and SHSS:B) by Weitzenhoffer and Hilgard (1959). The introduction of the Stanford Hypnotic Susceptibility Scale, Form C (SHSS:C) by Weitzenhoffer and Hilgard (1962) represented an improved version of the two earlier forms; it was comprised of a greater proportion of more difficult cognitive items. The SHSS:C is still the prevalent measure of hypnotic susceptibility in current use and is often the criterion by which other measures of hypnotizability are evaluated (Perry, Nadon, & Button, 1992). This instrument is essentially an ascending scale which begins with relatively easy hypnotic induction procedures and progressively moves to more difficult trance challenges.

A recent study by Kurtz & Strube (1996), comparing a number of hypnotic measures, described the SHSS:C as the gold standard of susceptibility tests. This study also addressed the idea of using multiple measures of hypnotic susceptibility in order to improve predictive power over using a single administered test. Kurtz & Strube (1996) concluded that the use of multiple measures of susceptibility was not warranted, and that the “rational” choice for a single measure of hypnotic susceptibility would be the SHSS:C.

Research with the EEG and Hypnotic Susceptibility

Brainwaves are the far-field electrical wave patterns set up by neurochemical activity in the living brain. The electroencephalograph (EEG) is an instrument which can measure this activity and determine its strength (higher or lower amplitude) and speed (high or low frequency). Scientists have characterized brainwaves into four broad categories: (a) beta, brainwaves above 13 cycles per second (or hertz), indicative of active consciousness; (b) alpha, a slower brainwave ranging from 8 to l2 hertz, characteristic of a relaxed conscious state of awareness; (c) theta, the next slower waves ranging from 4 to 8 hertz, often associated with dreamlike imagery and deep relaxation; (d) delta, the slowest waves from 0 to 4 hertz which can predominate during dreamless sleep.

The majority of early research with hypnosis shared a common goal: the development of a methodology to determine if, and when, an individual is hypnotized. The majority of early EEG research with hypnosis focused on the state of hypnosis, often attempting to distinguish the state of hypnosis from the state of sleep (Sabourin, 1982). Weitzenhoffer’s 1953 review of studies utilizing the EEG with hypnosis concluded that hypnosis is perhaps more akin to light sleep than either deep sleep or the waking state.

A shift occurred in the late 1960’s as researchers began investigating possible electrocortical correlates of hypnotic susceptibility using the EEG. The predominant focus in hypnosis research from this time forward was on individual differences rather that the hypnotic state per se. Much of the early research focused on alpha wave indices of hypnotic susceptibility. A review by Dumas (1977) found that no alpha-hypnotizability correlation existed in the general population. Additionally, a recent critical review by Perlini & Spanos (1991) offered little support for an alpha-hypnotizability relationship. Other early studies found greater resting theta wave activity with highly susceptible individuals (Galbraith, London, Leibovitz, Cooper & Hart, 1970; Tebecis, Provins, Farnbach & Pentony, 1975; Akpinar, Ulett, and ltil, 1971). Overall, the comparison of early EEG research proves difficult given the aggregate of technologies and methodologies employed over a span of time characterized by extreme variance in technological development.

Recent studies have reexamined the relationship between EEG measures and hypnotic susceptibility based on rigorous subject screening and control, along with enhanced recording and analytic techniques. Sabourin, Cutcomb, Crawford, and Pribram (1990) found highly hypnotizable subjects to generate substantially more mean theta power than did low hypnotizable subjects in frontal, central, and occipital derivations during resting nonhypnotic baseline, with largest differences observed in the frontal (F3, F4) locations. According to a review by Crawford and Gruzeiler (1992), theta activity, which is strongly and positively related to hypnotic susceptibility, is the most consistent EEG correlate of hypnotic susceptibility. The results of a recent study by Graffin, Ray & Lundy (1995) indicate that highly hypnotizable subjects demonstrate significantly more theta activity in frontal (F3, F4) and temporal (T3, T4) areas in comparison to low hypnotizable subjects at baseline measures. The studies by Sabourin et al. (1990) and Graffin et al. (1995) are alike in that each employed fast Fourier transformation (FFT) and power spectral analysis of monopolar EEG derivations, which allows for the examination of activity within each component frequency of each EEG epoch.

The position which is most supported in the contemporary literature is a consistent pattern of EEG activity which can differentiate individuals according to standardized hypnotic susceptibility scores. It is suggested that high-susceptible individuals produce more anterior theta activity as compared to low-susceptible individuals. This baseline individual difference is an important neuropsychophysiological indicator of hypnotizability and could prove to be a more stable individual difference measure than standard psychometric measures (Graffin et al., 1995).

Theta Waves and Perceptual Variations

The relationship between theta activity and selective attentional processes lends further support to a coexistent relationship with hypnotizability. The concepts of Class I and Class 11 inhibition have been presented by Vogel, Broverman, & Klaiber (1968). Class I inhibition is described as being correlated with a general inactivity or drowsiness, whereas Class 11 inhibition is related to more efficient and selective attentional processes. The Class 11 concept of slow wave activity is described by Vogel et al. (1968) as “a selective inactivation of particular responses so that a continuing excitatory state becomes directed or patterned (p. 172)”. Sabourin et al. (1990) suggested that the theta activity observed in highly hypnotizable subjects reflects involvement in greater absorptive attentional skills. As in the Sabourin et al. (1990) study, Graffin et al. (1995) provide suggestions regarding the selective attentional component of theta: ” high hypnotiizables either possess, or can manifest, a heightened state of attentional readiness and concentration of attention” (p. 128). The relationship between greater attentional readiness and frontal theta has also been suggested in psychophysiological studies (Bruneau et al., 1993; Ishihara & Yoshii, 1972; Mizuki et al., 1980). Another possible supportive line of research involves the examination of psychological absorption and hypnotizability relationships. Studies have found absorption to be consistently correlated with hypnotizability (Glisky, Tataryn, Tobias, Kihlstrom, & McConkey, 1991; Nadon, Hoyt, Register, & Kihlstrom, 1991; Tellegen & Atkinson, 1974). In a review of psychological correlates of theta, Schacter (1977) described the relationship between the hypnagogic state and the presence of low voltage theta activity. Green & Green (1977) described the theta state as that of reverie and hypnogogic imagery. They employed theta neurofeedback training to induce quietness of body, emotions, and mind, and to build a bridge between the conscious and unconscious. In describing theta EEG brainwave biofeedback, the Life Sciences Institute of Mind-Body Health (1995) associated increased theta activity with “states of reverie that have been known to creative people of all time” (p. 4).

Considering these findings related to theta activity, a relationship between individual levels of hypnotizability, selective inhibition, hypnogogic reverie, and theta activity is more easily understood. Relatively high theta activity may be indicative of a characteristic brainwave pattern which reflects an underlying cognitive mechanism that relates to a type of selective inhibition and hypnogogic imagery.

Research with Neurofeedback Training

Neurofeedback training works on the brain’s ability to produce certain brainwaves the way exercise works to strengthen muscles. EEG biofeedback instruments show the kinds of brainwaves an individual is producing, making it possible for that individual to learn to manipulate the observed brainwaves.

Demonstrated individual success acquiring the ability to self-regulate characteristic brainwave patterns is evident in the neurofeedback literature. Various protocols have been employed by many practitioners to enhance both relaxation (an increase in production of slow waves, such as theta, and a decreased production of fast beta waves) and mental activity (a decrease production of excessive slow wave, such as delta and lower frequency theta; with an increase in the production of ‘fast” beta waves). An impressive number of recent studies have demonstrated the efficacy of brainwave neurofeedback training. The work by Peniston and others with individuals with alcohol abuse issues (Peniston & Kulkosky, 1989, 1990, 1991; Saxby and Peniston, 1995) has provided remarkable results. Peniston has shown 13 month follow-up relapse rates of 20% (compared to 80% using conventional medical training), significant reductions in Beck Depression Inventory scores, and decreased levels of beta-endorphin in subjects treated with Alpha-Theta brainwave training. The area of attention deficit hyperactivity disorder (ADHD) has received strong attention from neurofeedback researchers (Barabasz & Barabasz, 1995; Lubar, 1991; Rossiter & Vaque, 1995). Lubar’s work has provided strong support for the effectiveness of a protocol designed for Beta-training (16-20 Hz) and Theta inhibition (4-8Hz ), with 80% of 250 treated children showing grade point average improvements of 1.5 levels (range 0-3.5) (Lubar, 1991). Objective assessments of the efficacy of neurofeedback training for ADHD have shown significant improvements on the Test of Variables of Attention (T.O.V.A.) scales and Wechsler Intelligence Scale for Children-Revised (WISC-R) IQ scores with subjects who demonstrated significant decreases in theta activity across sessions (Lubar, Swaamod, Swartwood, & O’Donnell, 1995). Additional studies with post-traumatic stress disorder (PTSD) with Vietnam veterans (Peniston, 1990; Peniston & Kulkosky, 1991; Peniston, Marrinan & Deming, 1993) have provided unprecedented results with a condition often very resistant to training with other interventions.

The work by Ochs (1994) with the use of light and sound feedback of EEG frequencies, EEG disentrainment feedback (EDF), is also promising in terms of modification of EEG patterns. However, unlike traditional EEG biofeedback, with Dr. Ochs’ device there is no need for the individual to be consciously involved in the process. The visual and auditory stimuli respond to and match the individual’s brainwaves and these stimuli are in turn generated by the overall frequency of the individual’s brainwaves. The aptitude of this system is the capacity for the clinician to alter the feedback frequencies upward or downward, in effect, providing flexibility into a “set” or “characteristic” brainwave pattern.

The flexibility of individual neurofeedback training is evident in the various approaches designed to intensify certain types of EEG activity either by itself, or to intensify certain types of EEG activity and decrease other types of EEG activity occurring at the same time. Overall, the relatively high number of recent neurofeedback training studies with consistent positive results strongly demonstrate the changes in cognitive and behavioral variables resulting from the alteration of individual brainwave patterns.

Research with Binaural-Beat Sound Stimulation

Binaural-beat stimulation is an important element of a patented auditory guidance system developed by Robert A. Monroe. In fact, Robert Monroe has been granted several patents for applications of psychophysical entrainment via sound patterns in (Atwater, 1997). In the patented process referred to as Hemi-Sync®, individuals are exposed to factors including breathing exercises, guided relaxation, visualizations, and binaural beats. Extensive research within the Monroe Institute of Applied Sciences, which has documented physiological changes associated with Hemi-Sync use, along with consistent reports of thousands of Hemi-Sync users, appears to support the theory that the Hemi-Sync process encourages directed neuropsychophysiological variations (Atwater, 1997).

The underlying premise of the Hemi-Sync process is not unlike that adopted by many EEG neurofeedback therapists, that an individuals’ predominant state of consciousness can be reflected as a homeostatic pattern of brain activity (i.e., an individual differential bandwidth activity within the EEG spectrum) and can often be resistant to variation. Atwater (1997) reported that practitioners of the Hemi-Sync process have observed a state of hypnagogia or experiences of a kind of mind-awake/body asleep state associated with entrainment of the brain to lower frequencies (delta and theta) and with slightly higher-frequency entrainment associated with hyper suggestive states of consciousness (high theta and low alpha). In line with current EEG research relating to ADHD (see Lubar,1991), Hemi-Sync researchers have noted deep relaxation with entrainment of the brain to lower frequencies and increased mental activity and alertness with higher frequency entrainment. The Monroe Institute has been refining binaural-beat technology for over thirty years and has developed a variety of applications including enriched learning, improved sleep, relaxation, wellness, and expanded mind-consciousness states (Atwater, 1997).

Binaural beat stimulation can be further understood by considering how we detect sound sources in daily life. Incoming frequencies or sounds can be detected by each ear as the wave curves around the skull by detraction. The brain perceives this differential input as being “out of phase”, and this waveform phase difference allows for accurate location of sounds. Stated simply, less noise is heard by one ear, and more by the other. The capacity of the brain to detect a waveform phase difference also enables it to perceive binaural beats (Atwater, 1997). The presentation of waveform phase differences (different frequencies), which normally is associated with directional information, can produce a different phenomenon when heard with stereo headphones or speakers. The result of presenting phase differences in this manner is a perceptual integration of the signals; the sensation of a third “beat” frequency (Atwater, 1997). This perception of the binaural-beat is at a frequency that is the difference between the two auditory inputs.

Binaural beats can easily be heard at the low frequencies (<30 Hz) that are characteristic of the EEG spectrum (Austere, 1973). This perception of the binaural-beat is associated with an EEG frequency following response (FFR). This phenomenon is described by Atwater (1997) as EEG activity which corresponds to the fundamental frequency of the stimulus, such as binaural-beat stimulation.

The sensation of auditory binaural beating occurs when two coherent sounds of nearly similar frequencies are presented one to each ear with stereo headphones or speakers. Originating in the brainstem’s superior olivary nucleus, the site of contralateral integration of auditory input (Oster, 1973), the audio sensation of binaural beating is neurologically conveyed to the reticular formation (Swann, Bosanko, Cohen, Midgley & Seed, 1982) and the cortex where it can be observed as a frequency-following response with EEG equipment. The word reticular means ‘net-like’ and the neural reticular formation itself is a large, net-like diffuse area of the brainstem (Anch, et al. 1988). The RAS regulates cortical EEG (Swann et al. 1988) and controls arousal, attention, and awareness – the elements of consciousness itself (Tice & Steinberg, 1989; Empson, 1986). How we interpret, respond, and react to information (internal stimuli, feelings, attitudes, and beliefs as well as external sensory stimuli) is managed by the brain’s reticular formation stimulating the thalamus and cortex, and controlling attentiveness and level of arousal (Empson, 1986). Binaural beats can influence ongoing brainwave states by providing information to the brain’s reticular activating system (RAS). If internal stimuli, feelings, attitudes, beliefs, and external sensory stimuli are not in conflict with this information, the RAS will alter brainwave states to match the binaural- beat provocation.

A recent study by Foster (1991) was conducted in an effort to determine the effects of alpha-frequency binaural beat stimulation combined with alpha neurofeedback on alpha-frequency brainwave production. Foster found that the combination of binaural-beat stimulation and alpha neurofeedback produced significantly higher alpha production than that of neurofeedback alone, but that the group which received only binaural-beat stimulation, produced significantly higher alpha production than either group. In a review of three studies directed towards the effects of Hemi-Sync tapes on electrocortical activity, Sadigh (1994) reported increased brainwave activity in the desired direction after virtually minutes of exposure to the Hemi-Sync signals.

Research to date, therefore, has suggested that the use of the binaural-beat sound applications can contribute to the establishment of prescribed variation in individual psychophysiological homeostatic patterns (brainwave patterns), which can precipitate alterations in cognitive processes. The relationship between individual patterns of cognitive variables and characteristic brainwave patterns affords not only a methodology for change, but also an objective unit for measure of change.

Purpose of the Present Study

The present study was an effort to develop, and to test the efficacy of, techniques designed to increase anterior theta activity and susceptibility to hypnosis as measured by currently employed standardized instruments. Contemporary hypnosis / EEG research studies have found individual electrocortical differences (anterior theta activity) to be reliable predictors of hypnotic susceptibility. Clinicians and researchers within the field of neurofeedback training have also demonstrated the efficacy of prescribed changes in individual EEG patterns and behavioral variables, with a number of medical and psychological disorders. Practitioners and researchers utilizing the binaural-beat technology developed by the Monroe Institute have produced impressive changes in individual EEG patterns. Given the strong support of brainwave modification, and the efficacy of the  binaural-beat sound patterns to modify brainwave patterns, it is logical and advantageous to make use of a binaural-beat sound based protocol. Since theta activity is positively related to individual level of hypnotic susceptibility, it follows that the employment of a protocol designed to increase frontal theta activity could also mediate an increase in hypnotic susceptibility. It was proposed that a binaural beat protocol designed to increase anterior theta activity will result in a significant increase in theta measure (% activity), and a related increase in hypnotic susceptibility, as measured by standardized instruments. In consideration of the previous association between hypnotic susceptibility and anterior theta activity, the potential exists for differential increases in theta activity relative to hypnotizability group. The examination of potential differential changes in theta activity relative to initial level of hypnotizability could provide further data supporting the association of theta activity and hypnotic susceptibility.

Research Hypotheses

Hypothesis l. Increases in hypnotic susceptibility, after exposure to binaural-beat sound stimulation protocol, will be observed for all participants from pre to post-measures. The Significant Change Index (SCI) was used to evaluate change between pre and post SHSS:C scores. Graphing was used to provide visual interpretation of individual level of hypnotizability.

Hypothesis 2. Theta activity will increase in all individuals as a result of the binaural beat sound stimulation protocol. The C Statistic was performed on the time series of theta measures across baseline and stimulus sessions for each individual.

Hypothesis 3. Increases in theta activity after exposure to binaural-beat sound stimulation protocol YAII be of greatest significance in individuals in the medium-hypnotizable group. The C Statistic was performed on the time series of theta measures across baseline and stimulus sessions for each individual.

Hypothesis 4. Increases in theta activity after exposure to binaural-beat sound stimulation protocol will be of least significance in individuals in the low hypnotizable groups. The C Statistic was performed on the time series of theta measures across baseline and stimulus sessions for each individual.

METHOD

Participants

Six participants were selected from a pool of Northern Arizona University (NAU) undergraduates who were administered the Stanford Hypnotic Susceptibility Scale, Form C (SHSS:C, Weitzenhoffer & Hilgard, 1962). The six participants were grouped according to varying degrees of hypnotizability (two lows, two mediums, and two highs) for participation in the stimulus sessions. The variations in hypnotic susceptibility within each group were minimal, assuring the participants were relatively homogeneous in terms of initial hypnotic susceptibility measures. To reduce the risk of attrition during this study, participants were paid $40.00 each for participation in the study.

Instrument

Stanford Hypnotic Susceptibility Scale, Form C (SHSS:C). Each participant’s score on the SHSS:C served as a baseline measure of hypnotic susceptibility. Also, after completion of the three stimulus sessions, raw scores were obtained on the SHSS:C for each participant a second time. The raw scores obtained in this post treatment evaluation provided an index of each participants’ hypnotic susceptibility level after exposure to the  binaural-beat stimulus protocol. The following general hypnotizability level designation and raw-score ranges are used with the SHSS:C: (a) low hypnotizable (0-4), (b) medium hypnotizable (5-7), (c) high hypnotizable (8-10), and (d) very-high hypnotizable (1 1-12). The Kuder-Richardson total scale reliability index, which provides a measure of the degree of consistency of participants’ responses, was reported by E. R. Hilgard (1965) as .85, with retest reliability coefficients ranging from .60 to .77 over the range of twelve items on the SHSS: C.

Apparatus

EEG-Recording. The NRS-2D (Lexicor Medical Technology, Inc.) is a miniaturized two channel Electroencephalograph (EEG) system. The device is approximately one inch tall, three inches wide, and six inches long and is connected directly to a 486 computer via the parallel port. It has a built in impedance meter and operates with both BIOLEX (BLX) neurotherapy software and NeuroLex (NLX) EEG acquisition software. The BLX and NLX systems comprise an array of tools including an audio/visual display system, graphing and reporting features, fast Fourier transformation and spectral analysis of complex wave forms, as well as conventional EEG recordings. An artifact inhibit feature stops all recording v,/hen the artifact (e.g., eye movement or other muscle signals) exceeds the selected artifact inhibit amplitude threshold. The computerized system was used to measure participants’ theta activity for each 2-second epoch. In the EEG data analysis, fast Fourier transformation was performed, and a power spectrum calculated, for each epoch.

Binaural-Beat Sound Tapes. The audio cassette tapes used in this study were produced by the Monroe Institute specifically for this study. Both a control tape and experimental tape were used in this study. The binaural beats provided in the experimental tape are unique in that they were designed to be complex brain-wave-like patterns rather than simple sine waves. The right-left differences in stereo audio signals on these tapes were assembled in a sequence to produce a dynamic wave pattern (brain-wave-like) as compared to a static, uniform sine wave pattern. Specifically, the experimental tape used in this experiment was produced with a binaural-beat pattern that represents a theta brainwave pattern of high hypnotic susceptibility. The Monroe Institute provided objective data verifying the binaural-beat components imbedded in the experimental tape, both in wave form and frequency spectra formats.

The experimental tape was produced with pink sound and theta binaural beats imbedded in carrier tones. The control tape was produced with pink sound and tones without binaural beats.

Procedures

General. For all participants, informed consent forms were provided. All participants mere debriefed at the completion of the study. All participants, at each stage of the study, were treated according to the ethical guidelines of the American Psychological Association.

Participant EEG Setup. During all sessions earlobes and the forehead electrode sites were cleaned with Ten-20 Abrasive EEG Prep Gel to decrease skin resistance prior to attaching EEG electrodes. Ten-20 EEG conductive paste was used as a conduction medium to fill the cups of silver-chloride electrodes. One monopolar EEG derivation was used, located according to the 10-20 system (Jasper, 1958) at FZ; the references were linked ears (R1, R2).

Participant Binaural-Beat Audio Setup. During all sessions participants wore headphones, providing audio input of pink sound and tones (baseline) or pink sound and theta binaural beats imbedded in carrier tones (stimulus).

Multiple Baseline EEG Recordings. The length of pre-stimulus session baseline for participants within each category of hypnotizability varied as follows: the duration of baseline recordings for Participant #1 was 5 minutes, Participant #2 was 10 minutes. For each category of hypnotizability, the two participants were exposed to a baseline session of either 5 or 10 minutes, and three 20 minute stimulus sessions. This procedure allowed participants to be exposed to the same stimulus sessions under “time-lagged” conditions. This approach is the foundation of the Multiple Baseline single-subject experimental design, which allows for examination of changes in stimulus sessions relative to the varied baseline periods.

Theta Measures. EEG measures of percent theta activity at frontal (FZ) placement were recorded during all sessions. Data were recorded at each 2second epoch during EEG recording. These data support trend analysis over time of baseline and stimulus sessions.

Hypnotizability Measures. Pre-stimulus data for level of hypnotizability (SHSS:C scores) were collected for each participant during the selection process. Post-stimulus sessions data for level of hypnotizability (SHSS:C scores) were collected following each participant’s last stimulus session.

Baseline Session. During this session participants were given information regarding-. (a) general understanding of theta binaural-beat sound stimulation and (b) the purpose/protocol of stimulus sessions. Prior to recording of EEG data, the experimenter instructed participants to close their eyes and to take two to three minutes to allow themselves to become relaxed. The experimenter instructed the participant to visualize herself as relaxed and comfortable and still, to experience a feeling of inner quietness. This procedure was used to allow the participant’s brainwave activity to stabilize prior to baseline recordings.

Binaural-Beat Stimulus sessions. The duration of each session was 20 minutes. Prior to recording of EEG data, the participants were allowed 2-3 minutes for stabilization of brainwave activity as previously described in the baseline session procedures. Prior to exiting the room, the experimenter started the cassette tape, the EEG recording function, and turned off the overhead light, leaving a single table lamp as a source of illumination in the room. The stimulus session was preset to terminate at 20 minutes. Each participant completed three sessions over a period of one week.

Interviews. Following each stimulation session, each participant was asked about her experience. This free-flow interview was used to assess the participants’ subjective experience of listening to the binaural-beat sound stimulation, and to test for adverse effects or reactions on the part of each participant.

Schedule of Sessions. The four sessions (1 baseline and 3 stimulus) were completed for each participant in two meetings within a five day period. During the initial meeting, the participants completed the first two stimulus sessions in addition to the baseline session. The sessions were scheduled in this manner to reduce participant response cost and to decrease participant attrition. Participants were allowed to take breaks of approximately 1 0 minutes between each session. The second meeting took place on the second day following the initial meeting. During this second meeting the participants completed the third stimulus session.

Data Analysis

Data were analyzed in order to evaluate changes in theta activity across sessions and changes in hypnotizability levels from pre-stimulus to post-stimulus scale administrations (SHSS:C).

The EEG data of each 2-second epoch during the baseline sessions were averaged to yield 10 data points for the 5-minute baseline recording and 20 data points for the 1 0-minute baseline recording. The EEG data for each stimulus session was averaged to yield 25 data points for each 20-minute recording.

In an effort to determine if the pretest to posttest change hypnotizability scores on the SHSS:C exceeded that which would be expected on the basis of measurement error, the Significant Change Index (SCI) as suggested by Christensen & Mendoza (1 986) was used. Descriptive techniques (graphical representations) were used to indicate the change in hypnotizability from pre to post-measures.

The C statistic was used to analyze the series of theta activity data across baseline and stimulus sessions. This approach was used to determine if a statistically significant difference existed between baseline and stimulus session observations of theta activity.

When comparing baseline and stimulus sessions observations, the C statistic provides information about changes in the level and direction between the two time series. In the determination of statistical significance of an obtained C value, a Z value is obtained from the ratio of the C value to its standard error of the mean. Graphical representations of the time series of theta activity measures were used to allow confirmation of the statistical findings by visual inspection of the data.

RESULTS

Participant Characteristics

The six participants in this study were female, ranging in age from 19 to 32. In order to facilitate association of each participant with relevant data, the following labels will be used in reference to the participants by hypnotizability group ( LOW, MED, HIGH) and by duration of baseline (1 = 5-minute baseline, 2 = 1 0-minute baseline). The three participants (one from each hypnotizability group) with 5-minute baselines are referred to as LOW1, MED1 and HIGH1, the three participants (one from each hypnotizability group) V,/ith 10 minute baselines are referred to as LOW2, MED2, and HIGH2. The majority of participants reported having no previous experience with relaxation-oriented experiences such as hypnosis, meditation, or formal relaxation training.

Test of Hypotheses

Hypothesis 1. Increases in hypnotic susceptibility, after exposure to binaural-beat sound stimulation protocol, will be observed for all participants from pre to post-measures. Both participants in the low-susceptibility group (LOW1, LOW2) increased by a raw score of 1 from pre to post-measures. Both of the participants in the medium-susceptibility group (MED1, MED2) increased to the raw score of 8. MED1 increased from a raw score of 6 to a raw score of 8, MED2 increased from a raw score of 7 to a raw score of 8. No changes in raw score values were observed with the participants in the high-susceptibility group (HIGH1, HIGH2) between pre and postmeasures. A calculation of the Significant Change Index (SCI) [used to assess pretest to posttest SHSS:C scores considering the standard error of the difference (SD) between the two test scores: SCI value > 1.65 denotes significance at p<.05 ] for each participant in the low and medium susceptibility groups revealed the following values: LOW1 – SCI = 1.96, SD =.51, p< .05; LOW2 – SCI = 1.96, SD = .51, p< .05, MED1 – SCI = 3.92, SD = .51, p< .05, MED2 – SCI = 1.96, SD =.51, p<.05. According to these calculations, a change of .84 or greater in rawscore value was required to establish a significantly different change in hypnotic susceptibility. Therefore, these data suggest that this hypothesis was supported in participants LOW1, LOW2, MED1, and MED2.

Hypothesis 2. Theta activity will increase in all individuals as a result of the binaural-beat sound protocol. Evaluation of intersession theta activity relative to baseline theta activity first required an analysis of baseline data to assure stability for subsequent comparison. In the examination of baseline trends of theta activity, the C statistic was calculated for each participant. LOW1 demonstrated no significant trend during the 5-minute baseline session (C = .18, n=10, p>.05). LOW2 demonstrated a significant downward trend during the 10-minute baseline session (C =.75, n=20, p<.05). MED1 demonstrated no significant trend during the 5-minute baseline session (C -.20, n=10, p>.05). MED2 demonstrated no significant trend during the 10-minute baseline session (C =.32, n=20, p>.05). HIGH1 demonstrated no significant trend during the 5-minute baseline session (C = -.28, n=10, p>.05). HIGH2 demonstrated no significant trend during the 10-minute baseline session (C = -.07, n=20, p>.05). In five of six participants, the baseline time series of theta activity data did not show a constant direction or trend, and indicated no departure from random variation. One participant (LOW1) demonstrated a significant downward trend. Therefore, the baseline data for all six participants provided adequate support for subsequent comparisons.

In the examination of trends in theta activity across baseline and the three binaural-beat stimulation sessions, the C statistic was calculated for each participant. LOW1 demonstrated a significant upward trend (C = .36, n=85, p<.01). LOW2 demonstrated a significant upward trend (C =.35, n=95, p<.01). MED1 demonstrated a significant downward trend (C =.74, n=85, p<.01). MED2 demonstrated a significant upward trend (C = .88, n=95, p<.01). HIGH1 demonstrated a significant upward trend (C =.70, n=85, p<.01). HIGH2 demonstrated a significant upward trend (C =.77, n=95, p<.01).

Thus, in five of six participants significant upward intersession trends in theta activity were observed. This significant intersession activity in relation to nonsignificant baseline activity provides support for this hypothesis in five of six participants.

Hypothesis 3. Increases in theta activity will be of greatest significance in the participants in the medium-hypnotizable group. An examination of the derived C statistic values for each hypnotic susceptibility group provided data regarding the relative significance of theta activity increases between groups. Mean C values for each susceptibility group (LOW, MED, HIGH) were calculated. The mean value for the medium-hypnotizable group does not include MED1, as this participant demonstrated a decrease in theta activity across stimulus sessions. Therefore, comparing the mean C value for the low and the high susceptible groups with the single C value for the medium susceptibility group which increased, the following values were obtained: LOW (M =.36), MED (M =.88), HIGH (M =.74). This analysis indicates a supportive trend in the data, but without inclusion of participant MED1, it does not provide support for this hypothesis.

Hypothesis 4. Increases in theta activity will be of least significance in the participants in the low-hypnotizable group. An examination of the derived C statistic values for each hypnotic susceptibility group provided data regarding the relative significance of theta activity increases between groups. Mean C values for each group of susceptibility (LOW, MED, HIGH) were calculated. The mean value for the medium-hypnotizable group does not include MED1, as this participant demonstrated a decrease in theta activity across stimulus sessions. The mean C values for each group of susceptibility are as follows: LOW (M =.36), MED (M = .88), HIGH (M = .74). Therefore, these data suggest support for this hypothesis.

DISCUSSION

Hypothesis l.

Increases in hypnotic susceptibility, after exposure to binaural-beat sound stimulation protocol, will be observed for all participants from pre to postmeasures. As mentioned earlier, the participants who demonstrated a significant increase in hypnotic susceptibility were Participants LOW1, LOW2, MEDI, and MED2. The participants in the high-hypnotizable group did not change in the measure of hypnotic susceptibility. Graphical analysis allowed for a simplified examination of the changes in hypnotizability levels from the pre to post binaural-beat stimulation administrations.

Inasmuch as no decreases in demonstrated raw-score values were observed across the six participants, these data suggest support of previous data indicating the relatively stable nature of hypnotic ability over time (Perry, Nadon & Button, 1992).

As previously mentioned, a potential ceiling effect may be present in the SHSS:C. The items on the SHSS:C are presented in a progressively greater difficulty. Data reported by Perry, Nadon & Button (1992) showed that 68% of the normative sample passed the first four items, and only 16% passed the last four items. The items begin relatively easy and become progressively more difficult and therefore are rank-ordered and do not meet interval level requirements. Thus, to accurately interpret of the findings of this study, the progressive organization of the SHSS:C items must be taken into consideration. The obtained changes in the medium-susceptible group may be more meaningful than observed changes in the low-susceptible group, as a change of 1 raw-score point would be a more difficult task in the medium-susceptible group than would a change of 1 raw-score point in the low-susceptible group. This indicates that the application of the Significant Change Index may not reveal the true significance of changes in hypnotic susceptibility with the SHSS:C. The organization of the SHSS:C is also an important factor in the ceiling-effect phenomena observed in the two participants in the high-susceptible group.

Low-Hypnotizable Group. The two participants in the low-hypnotizable group demonstrated modest increases in SHSS:C raw score values. Both participants LOW1 and LOW2 increased 1 raw-score value from 2 to 3. As previously suggested, the lack of initial hypnotic ability in less hypnotizable individuals often leads to unsuccessful attempts at modification of hypnotizability with this population. Although both participants in this group demonstrated only a single point increase in raw-score values on the SHSS:C, a positive increase suggests that modification of hypnotizability % with less susceptible individuals using binaural-beat stimulation can lead to positiveresults.

Medium-Hypnotizable Group. Considering the previously mentioned hierarchy of difficulty with the SHSS:C, it may be said that the two participants in the medium-hypnotizable group demonstrated the greatest increase in SHSS:C raw score values. Both participants MED1 and MED2 changed in general hypnotizability level from medium to high, with raw-scores of 6 to 8 and 7 to 8, respectively. These data also suggest support for Perry’s (1977) findings, in which successful modification of hypnotizability was most common in medium hypnotizable subjects.

These individuals appear to possess a certain essential cognitive framework or a predisposition which provides for a variety of hypnotic experiences, as demonstrated on the SHSS:C.

In relation to the effects of binaural-beat sound stimulation on hypnotic susceptibility, these data reveal mixed conclusions. An interesting point is that Participant MED1 demonstrated the largest increase in hypnotic susceptibility and also a significant decrease in theta activity in response to the binaural-beat sound stimulation. In contrast, Participant MED2 demonstrated the most significant increase in theta activity in response to the  binaural-beat sound stimulation. Therefore, these data indicate that theta activity is not the only contributing factor in hypnotic susceptibility, suggest that modification of hypnotizability with medium susceptible individuals using binaural- beat stimulation can be effective, and highlight the importance of individual variation. These data can provide a meaningful direction for researchers and practitioners of hypnosis interested in increasing hypnotic susceptibility.

High-Hypnotizable Group. The two participants in the high-hypnotizable group demonstrated no change in SHSS:C raw-score values. The possibility exists for a ceiling-effect with individuals scoring at the upper end of the SHSS:C scale. Both participants HIGH1 and HIGH2 had the same pre and post raw-scores, 9 and 10, respectively. The items or skills an individual must demonstrate to increase in raw score above 9 are cognitive items of greater difficulty including, negative and positive hallucination tasks. This potential ceiling-effect is also evident in Hilgard’s (1965) report on relative item difficulty within the SHSS:C, in which only nine percent of participants in the normative base passed the positive and negative hallucination tasks. These data suggest that those who are high in hypnotizability, in terms of the SHSS:C, may be less responsive to binaural-beat stimulation relative to individuals who demonstrate less hypnotic ability. Perhaps there is a ceiling effect on an individual’s abilityto produce theta as well.

Hypothesis 2.

Theta activity will increase in all individuals as a result of the binaural-beat sound protocol This hypothesis was supported in data from five of six participants, each showing an upward intersession trend in theta activity across stimulus periods. The subject in the medium hypnotizable group with the 5-minute baseline (MED1) demonstrated a downward intersession trend in theta activity across stimulus periods. The theta activity of Participant MED1 changed significantly in session-3. No significant change or trend in theta activity was observed for this participant prior to session-3. These data indicate that some confounding factor(s) may have been in effect during the session-3 stimulation/recording period of participant MED1.

In a post-hoc analysis of intersession theta activity, the C statistic was calculated for the five participants who demonstrated a significant increase in theta activity over the three binaural-beat stimulation periods. This analysis was employed to determine which of the three binaural-beat stimulation sessions produced the most significant increase in theta activity relative to the baseline measures. For all five participants, the data from the third stimulation session (session-3) produced C values of the highest significance relative to baseline. These third session C values follow. LOW1 (C =.49, n=35, p<.01), LOW2 (C = .67, n=45, p<.01), MED2 (C = .89, n=45, p<.01), HIGH1 (C = .62, n=35, p<.01, HIGH2 (C =.83, n=45, p<.01. These data suggest that continued exposure to binaural-beat stimulation could have an incremental positive effect on theta activity, and that in this study the most significant incremental effect was observed in the third stimulus session.

In a post-hoc analysis of intersession theta activity, the C statistic was calculated for all six participants using the combination of data from session-1 and session-2 relative to data from the baseline session. This comparison was done to further evaluate the initial effects of the binaural-beat sound stimulation. The following C values were revealed: LOW1 (C =.36, n=60, p<.01), LOW2 (C .30, n=70, p<.01), MED1 (C .11, n=60, p>.05), MED2 (C = .74, n=70, p<. 01), HIGH1 (C =.18, n=60, p>.05), HIGH2 (C =.36, n=70, p<.01). These data suggest that the binaural- beat stimulation effected an initial change (increase) in four of the six participants (LOW1, LOW2, MED2, AND HIGH2).

The two participants who did not demonstrate a significant increase in theta activity during the two initial sessions were MED1 and HIGH1. As mentioned earlier, Participant MED1 demonstrated a significant downward intersession trend across all three sessions, most obvious in session-3. The explanation of this anomalous response is uncertain, but as described in the introductory section on binaural-beat sound stimulation, a number of factors influence the EEG frequency-following response. Factors of primary interest in relation to theta activity are internal feelings, attitudes, beliefs, and overall mood-state. As theta is related to an overall relaxed state, any negative affect related to these factors could adversely affect theta production. Participant HIGH1 also demonstrated the most significant response in session-3. Participant HIGHI reported previous experience with head injury and EEG measurements. This experience involved an automobile accident in which the participant was knocked unconscious some ten years previous. Reported results of EEG at that time indicated an “abnormal” pattern during the sleep state. The relationship of possible brainwave abnormalities to measured theta activity in response to binaural-beat stimulation is not known. However, there is the possibility that the theta response of participant HIGH1 was affected by this head injury.

An additional post-hoc analysis was utilized to provide a precise evaluation of the immediate effect of the binaural- beat sound stimulation within the framework of the Multiple Baseline design. In this analysis, within each susceptibility group, the 1 0-minute baseline recording periods of Participant LOW2, MED2, and HIGH2 were compared to the 5-minute baseline recording periods appended with 5-minutes of the first stimulus session of Participants LOW1, MED1, and HIGH1. As previously stated, the participants within each susceptibility group assigned 10-minute and 5-minute baseline recording periods all demonstrated no significant upward trends in theta activity during baseline recordings. An examination of the initial five-minute stimulation period following the baseline period for the participants assigned the 5-minute baseline % within each susceptibility group revealed the following C values; LOW1 (C =.72, n=16, p<.05), MED1 (C =.27, n=16, p>.05), HIGH1 (C = .25, n=16, p>.05). The corresponding Z values for each C value stated above follow. LOW1 (Z = 2.99); MED1 (Z = 1.12); HIGH1 (Z = 1.02). Participant LOW1 demonstrated a significant upward trend during the initial 5-minute stimulus period, and participants MED1 and HIGH1 did not demonstrate a significant trend during the initial 5- minute stimulus period. As mentioned earlier, participants MED1 and HIGH1 did not demonstrate a significant increase in theta activity during the two initial sessions. In contrast, participant LOW1 demonstrated a significant increase in theta activity during all three stimulus sessions. These data highlight the power of individual differences in relation to theta brainwave activity. The observation that the initial recording of stimulus data seemed predictive of a differential theta activity response over time may be particularly important is this analysis. It may be that the significance of an initial theta activity response to binaural-beat sound stimulation is positively related to the significance of the theta activity response over time.

Hypothesis 3.

Increases in theta activity will be of greatest significance in the participants in the medium-hypnotizable group. The obtained unequal number of participants in each group, due to the exclusion of participant MED1 (this participant demonstrated a decrease in theta activity across stimulus sessions), presents difficulties in providing support for this hypothesis.

Participant MED2 demonstrated the highest significant overall increase in theta activity across the baseline and stimulus sessions primarily manifested in session-2 and session-3. Further support for this hypothesis is also indicated in the previously mentioned post-hoc analyses of (a) session-1 and session-2 combined relative to baseline, and (b) session-3 comparison to baseline. In both analyses, participant MED2 demonstrated the highest significant overall increase in theta activity.

Hypothesis 4.

Increases in theta activity will be of least significance in the participants in the low-hypnotizable group,  The observed unequal number of participants in each group, due to the exclusion of participant MED1 (this participant demonstrated a decrease in theta activity across stimulus sessions), also presents difficulties in providing support for this hypothesis. Even with this consideration, the observation that both participants LOW1 and LOW2 demonstrated the least significant overall increase in theta activity across the baseline and stimulus sessions suggests support for this hypothesis.

Conclusions

The findings of this study provide support for the efficacy of the binaural-beat sound stimulation process, pioneered by the Monroe Institute, in effecting an increase in theta brainwave activity. As mentioned earlier, the baseline and stimulus tapes differed only in the presence or absence of the binaural-beat stimulation (i.e., both contained pink sound and tones). Each participant demonstrated no significant upward trend in baseline recordings of theta activity. Thus, the observed trends in theta activity following introduction of the binaural-beat sounds allows one to state, with a good deal of certainty, that it is the effect of the binaural-beat sounds and not merely the passage of time, the measurement operation, or some other independent event that effected the observed increases in theta activity. During the post-session interviews, no descriptions of unpleasant experiences were reported, Individual reports of each stimulation session varied from profoundly insightful to pleasant and relaxing.

The single-subject experimental design used in this study allowed for examination of the effects of binaural beat stimulation on individual theta activity over time. With single-subject methodology there is no need to compromise the effects of stimulation on different subjects by averaging across groups as is done with group designs.

The data in this study relative to hypnotizability suggest support for the stability of hypnotic susceptibility over time and suggest support for previous data showing differential response to modification of hypnotizability relative to initial susceptibility level. This support is evident in the fact that no participant decreased in hypnotic susceptibility over time and in the differential participant responses across general hypnotic susceptibility levels. Surprisingly, the most significant increase in hypnotic susceptibility was observed in the participant with the most significant decrease in theta activity in response to the binaural-beat sound stimulation. Even though the significance of the decrease in theta activity for this participant was explained entirely by third session recordings, it is difficult to draw conclusions regarding the relationship of theta activity to hypnotic susceptibility when reviewing the findings of this study. Overall, this study indicates that theta activity is related to, but cannot uniquely explain, the variation in hypnotic susceptibility.

Limitations. Although the single-subject experimental design used in this study provided a direct examination of individual responses over time, the design of this study is not without inherent limitations. For example, as the participants in this study are not representative of the general population, it would be difficult to generalize the findings of this study, even to a similar group of females. It is worth noting, however, that the issue of external validity, which often essentially relates to possible inconsistencies in the data due to small sample sizes, is tempered somewhat in this study by the adequate number of recorded data points within each subject.

The demographic data were collected post-hoc, and thus prevented the homogeneous selection of subjects based on such variables as previous experience with EEG recordings or head-injury. Also, data collected in intersession interviews was not recorded for further analysis. This is unfortunate, as information regarding the subjective experience of binaural-beat stimulation is meaningful not only in and of itself but could have provided data relating to the differential participant theta activity in response to binaural-beat sound stimulation observed in this study.

Future Research.

In future related research with the use of binaural-beat stimulation, the time of exposure could be increased. An increase in exposure time could provide important data relating to modification of theta brainwave activity and hypnotic susceptibility. This could be easily accomplished by using a home-practice protocol, not unlike homepractice relaxation training commonly used in behavioral medicine settings with disorders such as migraine headaches. This type procedure would allow for extended stimulation periods in a true applied setting. Another possible line of research could involve the use of binaural-beat stimulation within background music during hypnotic procedures in an effort to increase participant response to hypnotic susceptibility evaluation measures. The use of “background support” via binaural-beat sound stimulation could also prove a valuable asset to clinical practitioners as well. Data from this study may also provide a foundation for subsequent group comparison designs directed toward the generalization of stimulation effects across larger groups of individuals.

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Music and Hemi-Sync in the Treatment of Children with Developmental Disabilities

Open Ear, 2, pp. 14-17, 1996

ABSTRACT 

The role of music and Hemi-Sync has been explored in the rehabilitation of 20 developmentally disabled children. The children ranged in age from 5 months to 8 years with an average age of 2 years. Within the broad category of developmental disability the children had received specific diagnoses of cerebral palsy (16), mental retardation (10 ), autism (5 ), and uncontrolled seizure disorder (4 ). The children were referred for therapy because of severe feeding and pre-speech problems. Eighteen of the children were non-verbal and non-ambulatory because of the motor incoordination of cerebral palsy or an overall delay in development.

THE PROGRAM 

Music was included in the child’s program as a way of creating an auditory environment to make learning easier. Music with a regular rhythm and a tempo of 60 beats-per-minute was selected to provide a quieting background and a regular rhythm and rate which was similar to the tempo of the heartbeat, sucking and walking rhythms. This structure of music has also been shown to increase the learning of verbal materials and enhance their retention. It is also probable that the regular rhythm and specific tempo of this music contributes to a greater symmetry of function of the two hemispheres of the brain. Largo and adagio movements from baroque composers such as Vivaldi, Bach, Albinoni and Correlli were selected for the therapy program. Modem compositions by Halpern (Comfort Zone) and Hoffman (Mind-Body Tempo) which contain the same structural elements were also used.

The response to this “superleaming music” was very positive. Most children become calmer and less distractible during the therapy sessions. Several showed a more normal response to touch and an increased ability to organize sensory information. The improved reactions were noted during the therapy period. There appeared to be minimal carryover of the improved sensory organization.

Because of the positive response to this type of nonverbal auditory facilitation of learning, a comparison of the child’s response to music alone and music containing Hemi-Sync signals was begun. In the initial phases of the program, the Metamusic series had not yet been produced. Robert Monroe imbedded a special tape of Halpern’s Comfort Zone with Hemi-Sync signals. This enabled a comparison of the child’s response to therapy under three conditions:

    1. no music,
    2. Comfort Zone and
    3. Comfort Zone + Hemi-Sync.

When the child showed a neutral or positive response to the Hemi-Sync version of Comfort Zone, other music containing the Hemi-Sync signals was introduced into the program. This included Metamusic Blue, Metamusic Green, Soft and Still and a wide variety of quiet background music combined with the Hemi-Sync synthesizer.

The child’s non-verbal responses to therapy were carefully documented. Each change of expression, body movement, shift of attention etc., was interpreted as a means of communicating like or dislike, comfort or discomfort with what was occurring at that moment. These non-verbal reactions became the clearest clues indicating whether a musical or Hemi-Sync background was acceptable to the child’s system. Non-verbal responses were positive in 18 of the 20 children. Two children showed negative responses. One older boy became more distractible and hyperirritable; a five-month-old girl screamed with the Hemi-Sync music. Both children tended to become irritable with high frequency sounds and responded negatively to any music containing higher pitches. It is possible that the high frequency tones which are often used in creating the Hemi-Sync signal may have been the interfering factors for these children.

The frequency with which Hemi-Sync was used and the total length of time in a program with a Hemi-Sync environment varied. The 18 children who continued to receive therapy combined with Hemi-Sync music were exposed to the signals primarily during their therapy periods. These varied from one to eight 45 minute therapy sessions per month. Hemi-Sync tapes were provided to the families of 11 children for use during one play-learning session at home and while falling asleep at night. The total length of time spent using Hemi-Sync tape varied from one month to three years. The majority of the children were involved with the tapes for approximately 4-6 months.

The purpose of the observations was to obtain a clinical impression of the role which Hemi-Sync in a musical format could play in the feeding and pre-speech rehabilitation of the child. The study was explorational in nature and formal data collection was not included. Clinical records were maintained which described the activities worked on, the child’s response and the type of auditory background which was used.

TRENDS 

Fifteen of the 18 children who continued to receive the music containing Hemi-Sync showed positive changes in behaviors worked on in therapy. During treatment sessions which did not utilize a musical or Hemi-Sync background, these changes were not evident. In several instances behavioral changes were noted with the “superlearning music” background; however the degree of change and permanence of change was more pronounced when Hemi-Sync was combined with the music. Three of the 18 children showed minimal or inconsistent changes in their behaviors with Hemi-Sync.

Five behavioral areas showed the greatest change as a result of treatment provided with a Hemi-Sync background:

Disorganized Sensory Input may be described as difficulty processing and integrating multiple sensory information. The child is unable to filter, discriminate and organize sensory input. The world becomes an over stimulating, chaotic environment. Reactions such as tactile hypersensitivity, irritability, disorganized movement patterns and distractibility are common. In response the child shows a variety of characteristics which may be interpreted as an attempt to cope or survive. These include withdrawal with poor eye contact, and rhythmical stereotypes such as rocking, flapping and spinning. Because of a lack of interactive response to the environment, these children are often diagnosed as severely retarded or autistic.

Five of the seven children whose behavior was characterized by disorganized sensory input showed major improvement as a result of the Hemi-Sync environment. Changes included:

    1. a reduction in tactile hypersensitivity and overall sensory defensiveness,
    2. an improved focus of attention for learning sensory discrimination,
    3. a reduction or elimination of coping strategies (withdrawal, poor eye contact, rocking, general autistic behaviors),
    4. improved sensory-motor organization resulting in improved movement patterns
    5. greater spontaneous exploration of the environment.

Two children with uncontrolled seizures showed a marked reduction in seizures as their ability to organize sensory input increased. The two children who had negative reactions to Hemi-Sync showed severe problems with sensory organization. It is hypothesized that the signal added to their overall sensory processing problems.

Distractibility can be defined as a less-severe manifestation of sensory disorganization. Children with this behavioral characteristic typically had difficulty sustaining a focus of attention to a task. Shifts of attention occurred with tactile, auditory and visual distractions. Several children were described as being hyperactive. A mild degree of tactile defensiveness was also seen. This correlation between tactile defensiveness and a hyperactive attention has been previously described in the literature. As a result of the poor focus of attention these children showed difficulty learning or retaining information and poor sustaining of coordinated muscle contraction. Increases in abnormal muscle tone and abnormal movement patterns were associated with attentional shifts in two children with severe athetoid cerebral palsy.

Four of the seven children whose learning was affected by poor focus of attention showed clinically measurable gains when treatment was provided with a Hemi-Sync background. Attention was more focused and the child was able to attend to activities involving listening and processing information. Two children with expressive language delays spoke their first words within a month of introducing the Hemi-Sync music. Three children made major gains in oral feeding and motor skills as a result of a more sustained focus of attention.

Three of the seven children in this group showed minimal gains in improving their attentional focus and reducing hyperactivity. Each of these children had a history of severe respiratory disorder. This varied from structural lung disorders related to prematurity to severe respiratory incoordination with irregular breathing and breath-holding. One child was on a portable oxygen unit. As a group, these children were unresponsive to Hemi-Sync. On days when the breathing was less stressful two children were able to respond with greater attention and less hyperactivity. One child who eventually showed major gains in focusing attention was initially highly inconsistent in his initial response to Hemi-Sync. Because there was no negative reaction and the music assisted the therapist in meeting his needs in a more creative fashion, Hemi-Sync music was continued as a background to therapy. Over a three month period (24 sessions) a change was observed in his breathing patterns. As the breathing became more regular and breath-holding incidents reduced, his attentional response to Hemi-Sync improved and he showed a consistently positive response to his therapy sessions. This was particularly significant since the no measurable gains had been seen in therapy for 9 months. It is possible that the other children with respiratory problems would also have profited from a longer trial with Hemi-Sync.

Motor Incoordination Difficulties are characteristic of children with cerebral palsy. The connection between the mind and body has received relatively little attention in these children. The involuntary body movements associated with athetoid and ataxic cerebral palsy frequently make it difficult for the child to focus attention for learning. In a similar fashion, difficulty sustaining a focus of attention can increase the involuntary shifts in muscle tone and abnormal movement patterns. Difficulties can include respiratory incoordination, involuntary movement and increases in muscle tone during thinking, and loss of postural stability when distracted.

Three children initially showed major difficulties in the relationship between attention and movement. Gains during the period of Hemi-Sync usage included:

    1. regularization of breathing patterns with more sustained vocalization,
    2. more sustained trunk control and postural stability,
    3. more normal movement patterns during sleep at night with greater ease of handling for dressing in the morning
    4. reduction of incoordination of feeding movements, and
    5. easier learning of new motor patterns during therapy.

Fear of Change in Vulnerable Areas is common in disabled children. who have had a stormy medical history. Long periods of hospitalization can create a deep-seated distrust of adults and new experiences. Severe respiratory problems can create an underlying fear of any experiences which stress breathing. Children with severe feeding problems often experience repeated failures and perceived threats to survival as they deal with problems of choking, aspiration and tube feedings. As the child deals with negative or stressful experiences and repeated failures, he begins to erect behavioral barriers which protect against further failure or perceived danger. These barriers can make it difficult for the tube-fed child to develop the oral motor skills which could eventually lead to oral feeding.

The addition of Hemi-Sync and music to the oral motor treatment program was highly beneficial for eight children who were fed by gastrostomy tube. There was less overprotection of the mouth and respiratory system and a greater willingness to use the mouth for exploration and discovery. It became easier for the child to develop a trust in the guidance of the therapist. It was also easier for the therapist to trust the child’s inner wisdom and develop a program which introduced new experiences without pushing.

Benefits to Others Sharing the Hemi-Sync Environment with the Child are seen as part of the overall change. When Hemi-Sync music becomes part of the therapy or home environment, it creates a shared envelope of sound which surrounds the child, therapist and family members. Changes during therapy sessions are related to the direct effect of the signals on the child’s central nervous system and the indirect effect of the signals on the information processing abilities of the therapist and parents. Because the Hemi-Sync signals contribute to a greater balance of activity of right and left hemispheres and cortical and subcortical areas of the brain, the adult working with the child is able to draw from a full repertoire of information processing abilities. There appears to be a greater awareness of non-verbal or subtle communicative signals and a greater trust of intuitive knowledge which may guide the therapy session.

Parents have reported changes in their own reactions to activities with the child when the tapes were used at home. One mother volunteered that she felt very relaxed when feeding her son and less angry and impatient with his feeding problems. Another mother was initially quiet and withdrawn during therapy sessions held at her home. She was often out of the room during therapy. She was interested in using Hemi-Sync tapes at home because she knew that her son was happier with the music. Within a month of regular Hemi-Sync use at home, she was more outgoing, wanted to be present during therapy sessions and offered more spontaneous comments about his progress and needs. Changes have also been observed in brothers and sisters. This was particularly evident when tapes were played for 45 minutes as children who shared a room were going to sleep. One sibling showed a reduction in bed-wetting and another showed major improvements in her school work.

CONCLUSIONS 

The results of this informal study show that Hemi-Sync in a musical format can be an effective adjunct to a pre-speech and feeding rehabilitation program. It serves to enhance the effectiveness of a program which is appropriate to the child’s needs. The fifteen children (75% of the group) who made gains in the program had not made similar gains when the program was implemented without the Hemi-Sync background. Significant changes occurred in thirteen of these children within the first two Hemi-Sync sessions.

It is important to establish a point of reference or baseline for the child’s behavior and skills without the use of the Hemi-Sync music background. Any changes which occur as Hemi-Sync is added to the program can be interpreted more meaningfully. The effectiveness of Hemi-Sync appeared to be cumulative. Children responded more consistently to sessions with Hemi-Sync as their experience with the signals increased. As the child experienced a more balanced and organized way of dealing with the sensory input for learning it became easier to re-create this new organization when the Hemi-Sync signals were not present. It is significant that major permanent changes were seen in children who experienced Hemi-Sync less than three hours per month. Hemi-Sync contributes to long-term changes in the child’s abilities and ways of organizing information.

The Facilitation of Attention Utilizing Therapeutic Sounds

by George Guilfoyle, Ph.D., and Dominic Carbone, Ph.D.

When each ear is presented simultaneously with a pure tone signal, and these tones differ by only a small amount (from 1 to 25 Hz), they continually mesh in and out of phase with each other to produce a binaural beat. According to Atwater (1996) “the binaural beat [is] perceived as a fluctuating rhythm at the frequency of the difference between the two auditory inputs” (p. 4). Apparently the binaural beats are generated in the brain stem and are associated with a pattern of electrical activity over the surface of the cortex known as the frequency following response, which can be measured by an electroencephalograph. Morris (1991) says: “For example, if the individual listens to a tone with the frequency of 440 Hz in one ear and another tone of 444 Hz in the other ear, a binaural beat of 4 Hz will be produced. This electrical signal occurs with relatively equal frequency and strength in both hemispheres of the brain and creates a synchronization of the two sides of the brain. Because of this synchronization, Monroe has called this effect Hemi-Sync® (p. 281).

Research investigations of brain activity patterns demonstrate that particular states of consciousness are associated with some of these patterns. Thus, the delta pattern (0.5 to 4 Hz) is associated with sleep, the theta pattern (4 to 8 Hz) with deep states of meditation, the alpha pattern (8 to 12 Hz) with relaxation, and the beta pattern (12 to 30 Hz) with concentration. What Hemi-Sync is apparently able to do is to create the possibility of attaining any one of these states of consciousness by varying the frequencies of the pure tones delivered to each ear, as well as by varying the differences between the two frequencies. Delivering the relevant frequencies to the listener’s ears, however, is only one factor in attaining a particular state of consciousness. The listener must be cooperative and in a receptive state of mind in order for the signals to work. In other words, it is not automatic. One can reject the effect if one so chooses.

Research with this technology is promising. Edrington (1984) used Hemi-Sync “cognitive learning enhancement tapes” with college students taking an Introductory Psychology course (Tacoma Community College, spring 1981). There were two sections taking the same course. One listened to Hemi-Sync during class, the other did not. Six tests were administered during the semester. In all but the first test, the students listening to the Hemi-Sync tapes scored, on the average, approximately ten points higher on each of the tests. The likelihood that these differences were the result of chance factors was no more than two times in a hundred.

Morris (1991) reported that when Hemi-Sync relaxation music was added to an ongoing program of remediation therapy with twenty developmentally disabled children suffering from feeding and pre-speech problems, fifteen of them showed positive changes in the problematic behaviors, including improvements in focus of attention, overall sensory organization, and motor coordination. Physical relaxation increased and there was a corresponding reduction in fearfulness and tactile defensiveness. According to Morris, “All of the children exhibited a greater openness and enthusiasm for learning” (p. 284).

Robert Sornson, executive director of special education for Northville Public Schools, Northville, Michigan, and fellow Monroe Institute Professional Members have investigated the use of Hemi-Sync with people suffering from attention deficit disorder (ADD). Sornson (Bullard 1995) noted that people with ADD exhibit lower levels of glucose metabolism in their brains. Generally they use less oxygen across the cerebral cortex, produce brain waves that are somewhat slower than normal, and have difficulty maintaining the high levels of arousal associated with sustained alertness and focused attention. The Hemi-Sync Remembrance tape that was employed was designed to foster quantum learning and peak performance. Although no formal investigation was carried out, reports from teachers and parents administering the Attention side of the Remembrance tape to children diagnosed with ADD indicate that the faster beta frequencies embedded in the music have resulted in improvements in the children’s focus of attention.

According to Zigler and Finn-Stevenson (1987) ADD children “tend to move from one site to another, they are unable to inhibit action, and they are constantly diverted by sounds and objects. Not only are the children chaotic in their behavior, they also tend to forget what they are told to do, and they seem at a loss when asked to engage in sequentially ordered behaviors (for example, when they are asked to go outside and fetch something)” (p. 460). These same symptoms–short attention span, distractibility, hyperactivity, impulsiveness, and emotional instability–can be seen in a number of mentally retarded/developmentally disabled (MR/DD) adults in day treatment settings. So if Hemi-Sync can improve the focusing ability of ADD children, can it perform a similar function with these MR/DD adults? To find out, we created a pool of twenty mentally retarded adults from members of our program population who expressed a willingness to participate in the study, matched them on the basis of IQ (Leiter International Performance Scale), then randomly assigned them to either an experimental or a control group. Both groups attended approximately fifteen sessions of one-half hour each extending over a two-month period.

The subjects in both groups sat in a double column of five rows placed in the center of a room approximately twenty feet by twenty feet equipped with large stereo speakers at the far ends of the back wall. Both groups watched nature videos without the sound tracks and listened to the Attention side of the Remembrance tape for thirty minutes per session. The only difference in the treatment given to the experimental and control groups was the Hemi-Sync signal which was present in the experimental condition and absent in the control. Before the treatment began and again after it was terminated, each subject was administered three subtests of the Wechsler Adult Intelligence Scale, each of which demands some degree of focused attention. The first, a test of short-term auditory memory, requires subjects to immediately repeat (forward or backward) sets of numbers spoken to them. Matarazzo (1972) noted that “difficulty in the reproduction of digits correlates with lack of ability to perform tasks requiring concentrated effort” (pp. 204-5). In the Block Design Test, which requires the subject to reproduce patterns of red and white blocks, the subject must simultaneously attend to both color and pattern in solving the problem. Finally, the Digit Symbol Test, which requires the subject to associate certain symbols with the numbers one through nine, perhaps more than the other two subtests, demands sustained focus throughout the whole test.

In addition to these measures, six five-point Likert type scales were created to measure various aspects of attentiveness. Two clinician-raters, both former teachers and both familiar with all of the participants in the study, rated each subject both before and after the treatment. The conditions under which they rated the participants were constant and tightly scripted. Each participant was introduced to the study, asked the same questions, and required to perform the same tasks. Their responses to the requirements of the situation provided the basis for the ratings. Also, the raters were unaware, throughout the experiment, of the composition of the groups. The ratings from each rater for each participant on each measure were averaged. Rater agreements on the six scales are shown in Table 1.

TABLE 1

Rater Agreement* on Six Measures of Attentiveness and Associated Behavior

SCALE

Pearson’s

P


r

values**

Attention to Task

.63

.005

Memory for Instructions

.91

.000

Resistance to Distractions

.81

.000

Attention to Speech

.62

.006

Level of Alertness

.36

.142

Level of Irritability

.71

.001

* As mentioned by Pearson’s product-moment correlation coefficient (r)
** P values represent probability that the associated r would have occurred by chance alone.


Following the last treatment session, subjects were retested and rerated. Difference scores were created by subtracting the scores they obtained on each test and rating scale before the treatment began from those obtained after the termination of the treatment. Positive scores indicate improvement. Scores of zero reflect no change. Negative scores indicate deterioration of performance. For both test scores and average ratings, the Mann-Whitney U Test was used to determine if the differences obtained from the two groups were likely to be the result of chance alone, or whether they represented a real effect.


TABLE 2

Average Differences in Raw Scores (Before and After) of Measures of Short-Term Auditory Memory and Perceptual-Motor Skills

SCALE

MUSIC PLUS HEMI-SYNC

MUSIC ONLY

MANN-WHITNEY
U STATISTIC

Digit Span

+0.1

0.0

75

Block Design

+1.6

-1.1

54

Digit Symbol

+2.8

-1.4

50*

* Differences significant at the .05 level of confidence.


TABLE 3

Average Differences in Ratings (Before and After) of Six Measures of Attentiveness and Associated Behavior

SCALE

MUSIC PLUS HEMI-SYNC

MUSIC ONLY

MANN-WHITNEY
U STATISTIC

Attention to Task

-1.0

-2.0

54

Memory for Instructions

+1.3

-0.9

86

Resistance to Distractions

+0.5

-1.0

46*

Attention to Speech

+1.3

-0.5

46*

Level of Alertness

+0.5

0.0

58

Level of Irritability

+1.0

-0.9

48*

* Differences significant at the .05 level of confidence.


In Table 2 we see that for the group exposed to the Hemi-Sync signal, all difference scores were, on the average, positive. By contrast, the average difference scores obtained by the group denied the Hemi-Sync signal were generally negative. Only in the case of the Digit Symbol Test, however, were the differences between the two groups significant, which is to say, not likely the result of chance. (You would expect to obtain differences as great as these only five times in a hundred by chance alone.)

In Table 3 we find a similar pattern. The difference scores obtained by the group exposed to the Hemi-Sync signal were, for the most part, positive, while the difference scores obtained by the control group were predominantly negative. Apparently, repeated exposure to the Hemi-Sync signal resulted in small but real improvements in focusing ability as expressed by increased resistance to distraction and attention to speech. In addition, those people exposed to the signal appeared more serene (less irritable) than their counterparts in the control group. These results seem to confirm earlier anecdotal findings regarding the focusing effect produced by repeated exposure to the beta-inducing frequencies embedded in the Remembrance tape. Interestingly, when asked if they would like to continue the sessions, all members of the experimental group, but only two or three members of the control group, raised their hands. In fact, for several weeks after the termination of the experiment, we were approached almost exclusively by former experimental group members asking when the sessions were to begin again.

From a practical standpoint the obtained increases in focused attention were–while real–not overly large. Nor did it seem that the effects had generalized appreciably to classroom behavior. A second study has been inaugurated to determine if greater exposure to the Hemi-Sync frequency patterns (longer sessions and more sessions) results in greater increases in attentiveness. This is being explored by exposing selected participants to the Hemi-Sync signal in twice-weekly individual sessions during which they are required to play computer games demanding sustained attention. Scores per game and number of games per session are being recorded. The early sessions (with no Hemi-Sync signal present) have been devoted to obtaining baseline data. Later, Hemi-Sync sessions will continue for a minimum of six months in order to gauge the long-term effects of the signal upon attentiveness.

References

Atwater, F. H. 1996. The Hemi-Sync process. Faber, Va.: The Monroe Institute.
Bullard, B. 1995. The road to Remembrance. Hemi-Sync journal 13 (1).
Edrington, D. 1984. A palliative for wandering attention. Unpublished paper. Tacoma, Wash.
Matarazzo, J. D. 1972. Wechsler’s measurement and appraisal of adult intelligence. 5th ed. Baltimore: Williams & Wilkins.
Morris, S. 1991. Facilitation of learning. In Neurodevelopmental strategies for managing communication disorders in children with severe motor dysfunction. Austin, Tex.: Pro-ed.
Zigler, E. F., and Finn-Stevenson, M. 1987. Children: Development and social issues. Lexington, Mass.: D.C. Heath and Company.

George Guilfoyle is a licensed psychologist in the state of New York. He has spent the bulk of his career working with the emotionally and physically challenged. He is presently a senior psychologist on the staff of the Young Adult Institute, Manhattan Day Treatment Program, which serves mentally retarded/developmentally disabled adults in New York City. Dr. Guilfoyle has been a Professional Member of The Monroe Institute since June, 1996. Co-investigator Dominic Carbone is psychology unit head at the Young Adult Institute. This article was adapted from a paper presented at the New York State Association of Day Service Providers Symposium, October 18, 1996, Albany, New York.

EEG and Subjective Correlates of Alpha-Frequency Binaural-Beat Stimulation Combined with Alpha Biofeedback

by Dale S. Foster
Memphis State University
May 1990

This study is dedicated to my Mom and Dad, my sisters, Denise and Diann, and my brother Doug without whose encouragement and support this project would have been much more difficult.

Acknowledgements

I would like to express my appreciation to Dr. Robert Crawford, Dr. Robert Davis, Dr. Todd Davis, Dr. Burl Gilliland and Dr. Kenneth Lichstein for their advice, encouragement and support throughout the completion of this work. I would also like to thank Dr. Jane Davis at Christian Brother’s College for the opportunity to solicit participants from her introductory psychology classes. My appreciation also goes out to Dr. Michael Daley, Ryan Eason and Palitha Jayasinghe in the MSU Electrical Engineering Department for their technical assistance in creating the hardware and software necessary for the A/D conversions of the EEG data.

I also express my thanks to Libby Keenan, Coordinator of MSU’s Computer Services Training Center, for her help with the software used to transform the raw data. I would also like to thank George Relyea, Manager of MSU’s Statistical Services, for his assistance with the SPSSX statistical analysis.

Abstract

The purpose of this study was to determine the effects of alpha-frequency binaural-beat stimulation combined with alpha biofeedback on alpha-frequency brain-wave production and subjective experience of mental and physical relaxation. The study compared the alpha brain- wave production and subjective report of mental and physical relaxation of four groups, each of which received brief relaxation response training and one of four treatments: 1) alpha-frequency binaural-beat stimulation, 2) visual alpha- frequency brain-wave biofeedback, 3) alpha- frequency binaural-beat stimulation combined with visual alpha biofeedback, or 4) artificially produced ocean surf sounds. Sixty volunteer undergraduate and graduate students were randomly assigned to the four groups and instructed to utilize their respective treatment as the “mental device” in Benson’s relaxation response paradigm while they relaxed with eyes open for twenty minutes. Two 2 X 4 mixed ANOVAs revealed that all groups evidenced increased subjective report of relaxation and increased alpha production. An interaction effect was found in which the group with both alpha binaural beats and alpha biofeedback produced more treatment alpha than the group with alpha biofeedback alone. Additionally, nine of the fifteen subjects with both binaural beats and feedback reported being able to control alpha production via their focus on the alpha binaural beats. The data suggest the possibility that binaural beats can be used to evoke specific cortical potentials through a frequency-following response. Further investigation is warranted into the possibilities of using binaural beats alone and in conjunction with brain wave biofeedback to promote the self- regulation and management of consciousness.

Introduction

In recent years, the self-regulation of physiological processes has received an increasing amount of attention from the behavioral science community due to a number of factors, the most important of which is the increasing sophistication of techniques for measuring and feeding back meaningful information concerning these processes. Technological advances in the areas of electronics and computers have promoted the application of cybernetic principles to such biological events as heart rate, blood pressure, skin temperature, electrodermal responses, and spontaneous and evoked cortical potentials (Yates, 1980). The ability to empirically quantify these biological events and their operant control has also sparked renewed interest from behavioral scientists in the objective study of the self- regulation of consciousness (Schwartz & Shapiro, 1976). In fact, although at one time conscious and/or volitional processes were considered to be outside the proper domain of psychological investigation, the study of consciousness is now viewed as a central issue in cognitive psychology (Davidson, Schwartz & Shapiro, 1983).

The empirical investigation of the operant control of spontaneous and evoked cortical potentials began with the invention of the electroencephalograph (EEG) by Richard Caton around 1875 (Empson, 1986). Since that time advances made in EEG technology have enabled feedback of specific cortical potentials in forms which have allowed individuals to achieve control over certain specific cortical potentials under certain conditions (Rockstroh, Birbaumer, Elbert, & Lutzenberber, 1984). EEG technology has promoted the conditioned self-regulation of electrical brain rhythms through biofeedback procedures and thus has enhanced operants’ abilities to self-regulate the behaviors and states of consciousness with which those rhythms are associated.

The empirical investigation of the sensory stimulation of cortical potentials also dates from Caton’s invention of the EEG. Various forms of rhythmic stimulation such as flashing lights or pulsing sound have been found to entrain the electrical activity of the brain through the frequency-following response (FFR). Another form of auditory stimulation which may invoke a FFR, although much more subtle than bursts of sound, is binaural beats.

The present study is viewed within the context of the empirical investigation of the self-regulation and management of consciousness. More specifically, the aspects of consciousness which are focused upon are those which relate to the self-regulation and management of alpha-frequency brain waves, a primary correlate of certain aspects of consciousness. A distinction is made between self-regulation and management of consciousness for two reasons. First, much of consciousness appears to be outside the realm of direct self- regulation. For example, regardless of the level of motivation for maintaining a waking state of consciousness, humans find themselves losing consciousness, or falling asleep, almost daily. Second, information concerning past and present events related to consciousness is useful for planning or managing present or future events related to consciousness. For example, if I am aware that I tend to move from a waking state into a sleeping state after being awake for a certain number of hours, then I may use this information to plan to be in or near a bed when that event occurs. Thus those aspects of consciousness which are outside of my direct control are managed rather than regulated.

In relation to this study, two techniques are considered, alpha brain-wave biofeedback and alpha-frequency binaural-beat stimulation. Alpha brain-wave biofeedback is considered a consciousness self-regulation technique while alpha-frequency binaural-beat stimulation is considered a consciousness management technique. The distinction adopted here between self- regulation and management, however, is seen as a conceptual convention for the promotion of clarity. Both techniques could be considered to contain components of both self-regulation and management of consciousness.

Brain wave biofeedback has already been demonstrated to be an effective technique for the self-regulation of consciousness (Brown, 1970; Green & Green, 1979; Kamiya, 1969). Through the presentation of auditory or visual stimuli which convey useful information concerning the amount of alpha or theta brain-wave production, subjects are able to voluntarily increase or decrease the production of those brain waves. Through the self- regulation of a specific cortical rhythm, one begins to control those aspects of consciousness associated with that rhythm. For example, if I am aware that alpha-frequency brain waves are associated with mental relaxation, I may learn to self-regulate my level of mental relaxation by learning to self-regulate my alpha-frequency brain waves. Brain wave biofeedback techniques are presently being used successfully in the operant conditioning of specific frequency bands as well as single neurons (Rockstroh, Birbaumer, Elbert, & Lutzenberger, 1984).

Although the existence of the phenomenon of binaural beats is well documented (Oster, 1973), the application of binaural-beat stimulation as a consciousness management technique has as yet received little attention except among a small population of researchers (Atwater, 1988; Hutchison, 1986; Monroe, 1982). However the principle of using sensory stimuli to entrain specific cortical rhythms through the frequency- following response is well documented (Gerken, Moushegian, Stillman, & Rupert, 1975; Neher, 1961; Sohmer, Pratt, & Kinarti, 1977; Stillman, Crow, & Moushegian, 1978; Yaguchi, & Iwahara, 1976).

Binaural beats are auditory brainstem responses which originate in the superior olivary nucleus of each hemisphere. They result from the interaction of two different auditory impulses, originating in opposite ears, below 1000 Hz and which differ in frequency between one and 30 Hz (Oster, 1973). For example, if a pure tone of 400 Hz is presented to the right ear and a pure tone of 410 Hz is presented simultaneously to the left ear, an amplitude modulated standing wave of 10 Hz, the difference between the two tones, is experienced as the two wave forms mesh in and out of phase within the superior olivary nuclei. This binaural beat is not heard in the ordinary sense of the word (the human range of hearing is from 20-20,000 Hz). It is perceived as an auditory beat and theoretically can be used to entrain specific neural rhythms through the frequency-following response (FFR)–the tendency for cortical potentials to entrain to or resonate at the frequency of an external stimulus. Thus, it is theoretically possible to utilize a specific binaural-beat frequency as a consciousness management technique to entrain a specific cortical rhythm.

The entrainment of the alpha rhythm is perceived as a justifiable starting point in this investigation. The alpha rhythm was discovered by Hans Berger around 1924 and has been the object of extensive investigation since. However, there is still disagreement concerning the nature and origins of alpha. The alpha frequency range is usually considered to be from eight to twelve cycles per second and is generally associated with a relaxed but awake state of consciousness. Kamiya (1969) was one of the first to demonstrate operant control of the alpha rhythm through an auditory feedback stimulus. Brown (1970) demonstrated operant conditioning of alpha activity through the use of a visual feedback stimulus. Both researchers reported that enhanced alpha activity was usually accompanied by subjective experiences of pleasant affect. Cade and Coxhead (1979), on the basis of EEG data from “some four thousand” (p. vii) subjects, maintain that the maintenance of a prominent alpha rhythm in the EEG is a prerequisite to developing a state of consciousness which they have reportedly quantified and termed “the awakened mind.” Elmer and Alyce Green in their book Beyond Biofeedback report that alpha and theta biofeedback training facilitated states of consciousness which were conducive to creative imagery and personal psychotherapeutic insights.

This study seeks to empirically examine some of the effects of alpha-frequency biofeedback combined with alpha-frequency binaural beats on EEG alpha production and subjective experience of mental and physical arousal. The rationale behind this approach includes the possibility that learning to enhance alpha-frequency brain waves by allowing the binaural beats to entrain the cortex through a FFR may provide the subject with a skill that is generalizable to other environments.

Purpose

The purpose of this study is to begin to examine some of the electroencephalographic (EEG) and subjective effects of alpha-frequency binaural beats stimulation alone and in combination with alpha-frequency brain-wave biofeedback. Conceivably, as the EEG and subjective effects of binaural beats become better understood, their use as a consciousness management technique will become more effective.

Need for the Study

The literature on alpha biofeedback training illuminates the fact that there is yet much research to be done on the nature of the alpha rhythm and the factors involved in its operant control. The already reported successful practical applications of alpha biofeedback training provide reasonable motivation to continue to explore the phenomenon. Additionally, the preliminary attempts to utilize binaural beats and the FFR to facilitate specific brain-wave frequencies provide adequate justification for further examination of binaural-beat stimulation in order to better understand its effects. A visual eyes-open biofeedback task may serve to compliment the binaural-beat technique by providing the subject a measure of degree of entrainment achieved. A computerized search of the Psychological Abstracts and Index Medicus revealed no examples of research combining alpha biofeedback with a binaural-beat technique. The importance of the alpha rhythm and the possible benefits of its operant control provide motivation to begin to examine alpha biofeedback paradigms in conjunction with binaural beats. This study will examine the effects of both eyes-open visual alpha biofeedback and a binaural-beat technique on the production of alpha-frequency brain waves and subjective report.

Research Question

This study addresses the broad research question concerning what the individual and interaction effects of alpha-frequency binaural-beat stimulation and alpha biofeedback are upon subjects’ EEG alpha production and subjective experience of mental and physical relaxation.

Hypotheses

The following four hypotheses were tested:

H(1) Alpha frequency binaural-beat stimulation will increase alpha brain wave production above eyes- open baseline levels.

H(2) Visual eyes-open alpha-biofeedback training will increase alpha production above eyes-open baseline levels.

H(3) The combination of visual eyes-open alpha- biofeedback training with alpha-frequency binaural-beat stimulation will interact to increase alpha production more than either technique alone.

H(4) The combination of alpha binaural beats with alpha biofeedback will result in increased subjective report of relaxation.

Definitions of Terms

For the purposes of this research the following terms are operationally defined as follows:

Alpha production: Alpha production is defined as the ratio of the 10.5 Hz band of the Mind Mirror II EEG (Blundell, undated; Cade & Coxhead, 1979) to the entire measured EEG spectrum.

Eyes-open baselines: Eyes-open baselines are defined as the ratio of the 10.5 Hz band of the EEG to the entire measured EEG spectrum during the two minute period of time after orientation and before the procedure while the subject is mentally and physically relaxed in dim ambient light with eyes open and gaze fixed.

Alpha-frequency binaural-beat stimulation: The alpha frequency binaural beats were produced by a model 201B Hemi-Sync Synthesizer (Instruction manual, undated) and vibrated at 10.5 Hz.

Visual eyes-open alpha biofeedback: Alpha feedback was provided by the 10.5 Hz band of a Mind Mirror II EEG (Blundell, undated; Cade & Coxhead, 1979). In dim ambient light subjects observed two lights which indicated strength of alpha production by diverging laterally from a middle point. Orientation to the procedure included information concerning oculomotor strategies which have been found to affect alpha production. Subjects were instructed to maintain a fixed gaze throughout the procedure and not to use other oculomotor strategies to control alpha production.

Subjective report: Subjective report of mental and physical relaxation is defined as scores on a Self-Report Form.

Assumptions

The analysis of variance techniques used in this study rest upon a mathematical model which assumes that the error effects are distributed normally in the treatment population, the error effects are independently determined and distributed in the treatment population, and the error effects vary homogeneously in the treatment population.

Limitations

This study is subject to the following limitations:

Inasmuch as no frequency of binaural beats is provided other than alpha frequency, the assumption is not made that any increase in alpha production is necessarily unique to alpha- frequency binaural-beat stimulation.

Due to the fact that subjects were not screened for susceptibility to the treatment stimuli, the variability of susceptibility between subjects may obscure the findings of treatment effects.

Although subjects were informed of oculomotor strategies which have been found to increase alpha production and instructed uniformly concerning their use, no objective control for use of oculomotor strategies was used.

Although dominant alpha frequencies vary between and among individuals, no effort was made to evaluate and feed back the dominant alpha frequency of subjects. It seems reasonable that a technique which provides a beat frequency which is more natural to the system would have greater impact on the system.

Review of the Literature

Since the discovery of the human electroencephalogram (EEG) numerous applications have been found for utilization of the developing knowledge of the electrical rhythms of the brain. Brain wave biofeedback research has contributed evidence of operant control of the EEG and continues to provide increasing illumination into the nature and functions of the brain’s electrical rhythms. The interaction of these rhythms with the environment has also become better understood with the aid of EEG technology by allowing measurement of the effects of sensory stimuli on cortical potentials. The frequency-following response (FFR) is the tendency for the EEG to become entrained to the frequency of an environmental stimulus. The following study employs a combination of alpha brain-wave biofeedback and utilization of the frequency- following response through an alpha-frequency binaural-beat technique in an effort to determine the subjective and EEG correlates of this combination.

Electroencephalography

The history of electroencephalography, the measurement and study of the brain’s electrical activity, dates back to the mid- to late nineteenth century when advances made in the science of electromagnetism began to be applied to human physiology. Richard Caton developed a technique for detecting the electrical activity from the exposed surfaces of the brains of living rabbits and monkeys. He demonstrated his findings at a meeting of the British Medical Association in 1875 and later published them in the British Medical Journal (Caton, 1875). He is credited with the discovery of the spontaneous EEG in animals and with demonstrating the ability to detect electrical brain responses to stimuli. In 1924 Hans Berger, a German psychiatrist, developed and applied electroencephalographic techniques for use with humans and in 1929 published his first paper on the subject (Empson, 1986).

Since Berger’s discovery, the human EEG has provided information which has promoted a wide variety of discoveries about the brain. Functional roles of different areas of the brain have been discovered (Giannitrapani, 1985), development of the brain has become better understood (Surwillo, 1971), and correlations have been found between EEGs and behavior, personality factors and mental disorders (Saul, David, & Davis, 1949; Glaser, 1963; Robinson, 1974).

The normal human EEG has a frequency range from 0.5 Hertz (Hz) to 30 Hz which is usually subdivided into four or five bands: delta (0.5-3.5 Hz), theta (4-7 Hz), alpha (8-12 Hz), beta (13-28 Hz), and gamma (28+ Hz). Each of these bands has been correlated with specific behavioral states. Delta frequency waves are generally associated with deep sleep, theta waves with light sleep or dreaming, alpha waves with relaxed consciousness, and beta and gamma waves with active consciousness. Modern computerized EEGs can provide immediate feedback of the brain’s electrical activity according to location, frequency, and amplitude. This information can be utilized to identify and possibly modify specific functional states of individuals. Also, this information, when compared with normative data, can be used to indicate deficiencies or specialties of function of an individual.

The Alpha Rhythm

Hans Berger is credited with the discovery of the human alpha rhythm in 1924 (Empson, 1986). Berger’s first recognizable pattern in the human EEG was a relatively dominant, stable, synchronous wave form of about ten cycles per second which occurred primarily when the eyes were closed and during states of relaxation. Berger also noted that alpha was replaced by beta waves when the eyes were opened or when the individual was engaged in mental activity such as arithmetic calculations. For Berger, alpha waves represented a form of automatic functioning, a state of electrical readiness which exists when the subject is awake and conscious but inattentive. By 1934 (Adrian & Matthews, 1934) a consensus had been reached that alpha activity was related to relief from both visual activity and attention (Klinger, Greqoire, & Barta, 1973). The relationship of alpha to both the visual/oculomotor system and mental activity has been an important factor in alpha biofeedback research.

In most individuals there is a fairly consistent alpha frequency of around 10 cycles/second (Wieneke, Deinema, Spoelstra, Storm Van Leeuwen, & Versteeg, 1980). Although the alpha range is usually defined to be from 8-12 Hz, within this range the actual dominant alpha frequency varies between individuals (Schwibbe, Bruell, & Becker, 1981), within individuals across time according to differing conditions (Banquet, 1972, 1973), and within some individuals’ brains at the same time (Inouye, Shinosaki, Yagasaki, & Shimizu, 1986). This variation of the alpha rhythm within and between individuals illustrates the complex and idiosyncratic nature of the phenomenon. Additionally, numerous variables have been correlated with the alpha rhythm in various ways.

Alpha and Arousal

Some researchers have attempted to relate alpha activity to physiological arousal. The alpha rhythm is most evident when the subject is awake, has closed eyes and is relatively relaxed, and tends to disappear or decrease when the subject engages in mental concentration or physical movement, or becomes tense, apprehensive or anxious. It has thus been described as occupying a mediating position on the continuum of nervous activation ranging from deep sleep to high emotional excitement as described by arousal theory (Malmo, 1959). Lindsley (1952) characterizes synchronized, optimal alpha rhythm as a state of relaxed wakefulness in which attention tends to wander, free association is enhanced, and behavioral efficiency of routine reactions and creative thought is good. Evans (1972) suggests that alpha is related to cognitive arousal and attention in a U-shaped manner in the sense that it disappears at either extreme of arousal and attention. Cade and Coxhead (1979) describe a two factor theory of arousal in which the alpha rhythm is indicative of relaxed cortical arousal. Other physiological measures such as skin resistance reflect peripheral or somatic arousal. In their model cortical and peripheral arousal interact but may vary independently.

Alpha and Hypnosis

A number of researchers have focused on the alpha rhythm as a possible physiological correlate of hypnosis. London, Hart, and Leibovitz (1968) found evidence that hypnotic susceptibility is positively correlated with higher levels of waking alpha production. However, other researchers attempting to replicate this finding have had both positive and negative results (Engstrom, London, & Hart, 1970; Evans, 1972; Galbraith, London, Leibobitz, Cooper, & Hart, 1970; Nowlis & Rhead, 1968; Ulett, Akpinar, & Itil, 1972).

Alpha and Meditation

In the late 1950’s and early 1960’s research into the EEG effects of meditation began to reveal that the alpha rhythm appears different during meditation and may undergo long-term changes in persistent meditators (Bagchi & Wenger, 1958; Kasamatsu & Hirai, 1969). Anand, Chhina, and Singh (1961) reported that the EEG of meditators showed a high amplitude slowed alpha rhythm which gradually spread from the occipital to the frontal areas. Banquet (1973) also found high amplitude alpha rhythms during meditation. Additionally, Banquet noted a second stage of meditation in which theta frequencies appeared and moved from frontal to posterior channels. A third stage, which Banquet observed in only the most experienced meditators, was characterized by high-frequency beta waves over the whole scalp. Banquet also noted that during meditation alpha blocking did not occur to low intensity light and sound stimulation. Empson (1986) summarizes the recent research on meditation and concludes that the experience of meditation “requires the constant maintenance of a fairly low level of arousal which allows the sort of dissociated, free-associative thinking that meditation entails” (p. 31). The low-frequency, high-amplitude alpha rhythms generally found during meditation thus seem to represent a voluntary lowering of arousal by the meditator.

These findings concerning the EEG activity of meditators sparked increased interest in the meanings of these rhythms and how to control them. Stewart (1974) observes that the interest in alpha brain wave biofeedback training appears to have originated from EEG monitoring of Zen and Yoga practitioners. The perceived link between meditation and alpha production influenced many to assume that increased alpha production would result in the ability to reap the benefits of meditation. This assumption has been a driving force behind the interest in alpha biofeedback training. However, over two decades of research into alpha biofeedback training indicates that this assumption is at best simplistic.

Alpha Biofeedback Training

Alpha biofeedback training was first introduced by Kamiya in 1962 (Kamiya, 1969) when he demonstrated that subjects who were required to guess whether or not alpha was present in their EEGs and were subsequently informed of their accuracy, could, within a few hours, correctly identify when they were producing alpha with high accuracy. He also found that those subjects who were successful in discrimination training could also produce or suppress alpha activity at will. He later successfully utilized auditory alpha-biofeedback devices which informed subjects of their alpha production through the presentation or absence of a tone generated by their alpha rhythms (Nowlis & Kamiya, 1970). The mental states which Kamiya’s subjects associated with increased alpha production were reported to be feelings of relaxation, “letting go,” and pleasant affect.

Brown (1970) studied alpha biofeedback in an eyes open condition and found that subjects were able to increase their alpha production with a visual feedback stimulus in the form of a small blue light which was activated by alpha production. She reported that successful alpha enhancement was correlated with subjective experiences of narrowing of awareness and pleasant feeling states. Other researchers have reported successful attempts to enhance alpha production with both visual and auditory feedback (Green, Green, and Walters, 1970; Honorton, Davidson, and Bindler, 1972; Inouye, Sumitsuji, & Matsumoto, 1980). Although Kamiya and Brown used the occipital regions to train alpha, successful alpha training has also occurred using central (Potolicchio, Zukerman, & Chernigovskaya, 1979), parietal and frontal regions (Nowlis & Wortz, 1973). There has also been success training interhemispheric synchronization of alpha (Mikuriya, 1979).

Since the advent of alpha biofeedback training, research in the area has revealed relationships between alpha production and such diverse topics as pain control (Pelletier & Peper, 1977) and extrasensory perception (Rao & Feola, 1979). Alpha production has also been correlated in various ways with creativity (Martindale & Hines, 1975), reaction time (Woodruff, 1975; Ancoli & Green, 1977), locus of control (Goesling, 1974; Johnson & Meyer, 1974), neuroticism (Travis, Kondo, & Knott, 1974b), and other personality variables (Degood & Valle, 1975).

Alpha Training and Contingent Feedback

One of the most fundamental principles of biofeedback is the necessity of accurate monitoring and feedback of the physiological process of interest in order for that process to be operantly controlled. It seems to be a comment on the complexity of the phenomenon of alpha biofeedback that after over twenty years of research there is still a lack of agreement among researchers that the increased alpha production observed in alpha biofeedback training paradigms is dependent upon the presence of accurate contingent feedback. While some researchers contend that alpha control is dependent upon true feedback (Kondo, Travis, Knott, & Bean, 1979; Pressner & Savitsky, 1977; Travis, Kondo, & Knott, 1974a), other researchers have found that alpha enhancement occurs under conditions of false feedback or no feedback and is thus less dependent upon accurate feedback than on other situational factors such as expectancy, instructions, or reinforcements other than the feedback (Brolund & Schallow, 1976; Holmes, Burish, & Frost, 1980; Lindholm & Lowry, 1978; Lynch, Paskewitz, & Orne, 1974; Prewett & Adams, 1976; Williams, 1977).

EEG Alpha and the “Alpha Experience”

According to the early research into alpha control, the successful enhancement of alpha was accompanied by “pleasant feeling states,” “dissolving into the environment,” altered perception of time, relaxation, “letting go,” “letting mind wander,” and visual inattentiveness (Brown, 1970; Nowlis & Kamiya, 1970). These observations led to the conclusion that enhanced alpha production resulted in an altered state of consciousness referred to as the “alpha state.” However, further research into the subjective experiences which accompany alpha biofeedback training reveal that there are many other factors involved which influence these experiences. While some research indicates that the “alpha experience” requires both enhanced EEG alpha production and an “instructional set” (Walsh, 1974), other research indicates that the “alpha experience” does not necessarily accompany high or enhanced levels of EEG alpha (Plotkin, 1976, 1978; Plotkin & Cohen, 1976; Plotkin, Mazer, & Loewy, 1976), and may be relatively independent of alpha production (Plotkin, 1979). Enhanced alpha has been accompanied by elevated mood states as well as neutral or unpleasant mood changes (Bear, 1977; Cott, Pavloski, & Goldman, 1981; Travis, Kondo, & Knott, 1975). Marshall and Bentler (1976) contend that the level of physical relaxation is probably the determining factor in the experience of the “alpha state” rather than the amount of alpha production. This interpretation lends itself to a discrimination between cognitive and somatic relaxation. Although alpha production is related to both physical and mental arousal, it is neither a necessary consequence of nor a prerequisite to physical relaxation. Nor is it necessarily accompanied by pleasant affect. It is a multifaceted phenomenon which exists in a web of relationships with these and other variables.

Alpha and the Oculomotor System

As was mentioned earlier, Berger recognized that alpha production was somehow associated with both the visual system as well as mental effort. The further definition of these associations has been an ongoing theme since Berger’s discovery. While Kamiya and Brown were further defining the links between alpha and subjective experiences of relaxation and pleasant affect, other researchers were further defining the links between alpha and the oculomotor system (Dewan, 1967; Mulholland & Evans, 1966).

The assumption that increased alpha control results in increased control over arousal breaks down when the link between alpha and the oculomotor system is not controlled for (Goodman, 1976). Brown (1974) relates an incident in which a colleague who had been practicing alpha biofeedback requested to have his EEG monitored in her lab to check his progress. They discovered that he had learned to control his alpha production by moving his eyes, not by producing it by itself. Even though he thought he had learned to control his alpha production by lowering his level of arousal, he had actually only learned to keep the alpha feedback tone on by unconsciously discovering and using another mechanism by which alpha may be controlled. The fact that the alpha rhythm is correlated with numerous cognitive and behavioral variables has spawned controversy over whether or not cognitive strategies are primary factors in alpha control or merely mediate oculomotor control of alpha (Hardt & Kamiya, 1976; Plotkin, 1976a; Plotkin, 1976b).

Alpha Control and Baseline Alpha

The intimate relationship between the oculomotor system and the alpha rhythm has revealed some design difficulties in alpha training procedures. It seems that success in increasing alpha density depends partially on whether or not eyes-open or eyes-closed baselines are used and upon the amount of light available during the training procedure. Paskewitz and Orne (1973) compared two groups of subjects who were trained with alpha feedback tones. One group was trained in total darkness and the other was trained in dim ambient light. The group trained in darkness demonstrated no increases in alpha densities while the group trained in dim ambient light demonstrated increases in alpha densities compared to eyes- open baseline levels. Neither group demonstrated increases in alpha when compared to eyes-closed baselines. They concluded that alpha training can lead to changes in alpha densities only when conditions have lowered alpha densities below the levels spontaneously seen under optimal conditions. They concluded, “Subjects can acquire volitional control over alpha activity only under conditions which normally lead to decreased densities. . . Alpha feedback training may enable a subject to overcome suppressing effects when they are present” (p. 363). They further state that the pleasant subjective experiences reported to be associated with alpha feedback training are likely consequences of the acquisition of skill in disregarding stimuli in the external and internal environments which would ordinarily inhibit alpha activity. Seen within this context, they describe an increase in alpha density as not an end in itself but an index of the subject’s ability to disregard or remain unaffected by alpha blocking stimuli.

Other studies have indicated that the individual subject’s baseline alpha amplitude and density is an important factor in obtaining increases in alpha through feedback training (Kondo, Travis, & Knott, 1973).

Alpha and Attention

Alpha is usually associated with mental states of nonattention, disappearing when the individual focuses attention on something either in the external or internal environments. Brown, however, (1974) reports that during visual alpha feedback training sessions her subjects demonstrated alpha during the periods when they were attending to the visual stimulus and produced desynchronized beta frequencies during the rest periods when they were not attending to the feedback light. The link between alpha production and attention is thus more complex. She noted that “the subjects who lost awareness of all environmental factors except the light . . . were those subjects with the highest levels of alpha production. Conversely, the subjects who remained aware of the environment . . . produced the smallest amounts of alpha” (Brown, 1974, p. 333). One interpretation of this seeming paradox is that the subjects entered a state of selective attention which did not require an alert, no-alpha EEG. Possibly, the subjects were attending to being nonattentive during the feedback trials and became less attentive to being nonattentive during the rest periods.

Alpha and Anxiety

There are indications that alpha production is related to anxiety (Nowak & Marczynski, 1981). However, the use of alpha-biofeedback training to reduce anxiety has met with mixed success. Hardt and Kamiya (1978) reported that with high trait anxiety subjects alpha training resulted in anxiety reduction in proportion to alpha increases and anxiety increases in proportion to alpha suppression. Watson, Herder, and Passini (1978) report long-term improvement in both state and trait anxiety with alcoholics who participated successfully in alpha training. Plotkin and Rice (1981), however, found that anxiety reduction was related more to perceived success in the feedback task than to actual changes in alpha production. They thus attribute the reductions in anxiety that occur during alpha feedback training to placebo effects.

In a study by Orne and Paskewitz (1974) subjects were given alpha feedback training and were told that their alpha production would determine whether or not they would receive electrical shock during periods signaled by a tone. Although the subjects indicated increased physiological and psychological arousal during times of jeopardy, as measured by increased heart rate, skin conductance responses, and reported subjective apprehension and anxiety, their alpha production was not affected. These results indicate that a reduction in alpha production is not a necessary consequence of increased anxiety or physiological arousal. However, the results do not necessitate the conclusion that increased alpha production does not reduce anxiety.

Therapeutic Applications of Alpha Training

Although there have been reports of unsuccessful attempts to utilize alpha biofeedback training therapeutically (Hord, Lubin, Tracy, Jensma, & Johnson, 1976; Leib, Tryon, & Stroebel, 1976; Mandelzys, Lane, & Marceau, 1981; Watson & Herder, 1980), positive results have been reported with several therapeutic applications. Goldberg, Greenwood, and Taintor (1976) reported that a decrease in illicit drug use accompanied learned control of alpha in four chemically addicted subjects. Peniston and Kulkosky (1989) utilized alpha-theta brain-wave training with alcoholics and reported long-term improvement in depression scores and sustained prevention of relapse. Alpha training paradigms have been successful in reducing seizures and abnormal brain rhythms in epileptics (Johnson & Meyer, 1974a; Rouse, Peterson, & Shapiro, 1975; Sterman, 1973). Success has been noted in the treatment of migraine headaches (Andreychuk & Skriver, 1975; Cohen, McArthur, & Rickles, 1980), although alpha training was not found to be superior to other biofeedback strategies. The control of pain has been found to be related to alpha production in meditators (Pelletier & Peper, 1977) and alpha-biofeedback strategies have been found to facilitate control of chronic pain in conjunction with hypnotic suggestion (Melzack & Perry, 1975) and stress inoculation training (Hartman & Ainsworth, 1980). Mills and Solyom (1974) used alpha training successfully with five ruminating obsessives and found that virtually no ruminations occurred during alpha, indicating possibilities for further research and application of alpha training in this area. Alpha suppression training has been successful improving performance on an arithmetic task with mentally retarded subjects (Jackson & Eberly, 1982), and improving attention and reading skills (Ludlam, 1981).

Binaural Beats and the Frequency-Following Response

As has already been seen, the alpha rhythm is influenced by many factors, both internal and external. Environmental factors such as photic and auditory stimulation have been found to influence alpha production in various ways. Flickering lights can entrain the electrical rhythms of the brain through the frequency- following response. A more subtle example of the frequency-following response occurs through binaural beats, an auditory brainstem response.

Photic Stimulation

Research clearly indicates the possibility of entraining specific frequencies of brain waves by presenting subjects with frequency-specific flickering lights (Arinibar & Pfurtscheller, 1978; Nogawa, Katayama, Tabata, Ohshio, & Kawahara, 1976; Regan, 1966; Williams & West, 1975; Yaguchi & Iwahara, 1976). For example, alpha-frequency brain waves may be entrained by exposing subjects to a light stimulus flickering at a rate within the alpha frequency range. The tendency for the electrical rhythms of the brain to become entrained to frequencies of sensory stimuli in the environment is called the frequency-following response (Moushegian, Rupert, & Stillman, 1978; Sohmer, Pratt, & Kinarti, 1977; Stillman, Crow, & Moushegian, 1978).

Auditory Stimulation

Research also indicates that auditory stimuli can be used to entrain the electrical rhythms of the brain (Neher, 1961; Picton, Woods, & Proulx, 1978a; Picton, Woods, & Proulx, 1978b). Auditory entrainment of cortical rhythms can occur through two different routes. One may achieve entrainment through bursts of sounds such as through drum beats, or one may achieve entrainment through the less direct and more subtle route of binaural beats.

The range of the electrical rhythms of the human cortex is 0 Hz to about 40 Hz. Since humans have an auditory range of 20 to 20,000 Hz, it is not possible to directly entrain cortical rhythms below 20 Hz with pure tones. However, the phenomenon of binaural beats, an auditory brainstem response, allows the entrainment of frequencies below 30 Hz through the interaction of pure tones within the superior olivary nuclei.

In 1839 H. W. Dove, a German experimenter, discovered the auditory effect of binaural beats (Oster, 1973). He found that when two different frequencies of sound were presented, one to each ear, a third frequency equal to the difference between the two frequencies was experienced. This third, binaural beat is actually the result of the interaction of the two primary tones within the auditory brainstem. For example, if a pure tone with a frequency of 400 Hz is presented to one ear and a second tone of 410 Hz is presented to the other ear, a third binaural beat with a frequency of 10 Hz will also be heard as a result of the interaction of the two frequencies. Binaural beats can be generated at frequencies below 40 Hz and may be used to entrain electrical rhythms of the brain to vibrate at the same frequency through the frequency-following response (Dobie & Norton, 1980; Gerken, Moushegian, Stillman, & Rupert, 1975; Moushegian, Rupert, & Stillman, 1978; Smith, Marsh, & Brown, 1975; Smith, Marsh, Greenberg, & Brown, 1978; Sohmer, Pratt, & Kinarti, 1977; Stillman, Crow, & Moushegian, 1978; Yamada, Yamane, & Kodera, 1977). Mediating processes through which the auditory brainstem binaural beat may entrain the cortex are likely to include attentional and motivational factors. Binaural-beat techniques are reportedly being used to successfully entrain specific brain-wave frequencies for specific purposes (Atwater, 1988). Preliminary reports indicate that the techniques may lend themselves to therapeutic applications. The combination of binaural beats and brain wave biofeedback may also prove therapeutically useful in the future.

Methodology

The Pilot Study

A pilot study was implemented January 1989, in order to further define the parameters necessary to test the utility of binaural beats in enhancing alpha production. The purposes of the study were to determine (a) the effectiveness of the binaural- beat technique in enhancing alpha production within a single session, (b) the effectiveness of the binaural-beat technique in enhancing alpha production across sessions, and (c) the number of sessions necessary in order for the binaural-beat technique to enhance the self-regulation of alpha in subjects.

Method

Subjects

Four volunteer students, one undergraduate female, one graduate female, one undergraduate male, and one graduate male, were used ranging in age from 20-38. A total of eighteen sessions of usable data was compiled. One subject completed six sessions, two subjects completed five sessions, and one subject completed two sessions.

Procedure

The initial session included a discussion of a handout describing the components of the “relaxation response” (Benson, 1975) and a brief introduction to the binaural-beat phenomenon. Subjects were told that the experiment was designed to provide a binaural beat to serve as the “mental device” (p. 27) in Benson’s paradigm. Subjects were reminded of the importance of maintaining a passive attitude and focusing on the binaural beat before each session.

The procedure for each session was the same; (a) subjects completed a brief pre-test of subjective experience of relaxation and anxiety, (b) subjects were given instructions to relax and breathe slowly and deeply for three to five minutes, (c) EEG activity was recorded while subjects listened with eyes closed for seven minutes each to three conditions of sound–artificially produced surf sounds, surf sounds with audible alpha-frequency binaural beats, and surf sounds with subaudible alpha-frequency binaural beats, (d) subjects completed a brief post-test of subjective experience of the procedure and levels of relaxation and anxiety.

Instruments

The binaural beats were produced by a Model 201B Hemi-Sync Synthesizer (“Instruction Manual,” undated). EEGs were recorded bipolarly from occipital and temporal sites of both hemispheres (T3, T4, 01, & 02 sites as per Jasper, 1958) by a Mind Mirror II EEG (Blundell, undated; Cade & Coxhead, 1979).

Scoring

Average alpha ratios were computed for each condition of each session. Each of the 28 channels was sampled three times per second. For each condition a ratio of alpha/all frequencies was computed. These ratios were utilized in the statistical analysis.

Results

Early in the study it became evident that methodological refinements were needed in order to demonstrate any effects of the binaural beats. The analysis of variance of the data revealed that there were no significant differences in alpha production either within sessions across conditions or across sessions. Although alpha production was observed to increase in the binaural-beats condition early in some sessions, a tendency was observed for the subjects to move through alpha into desynchronized theta, indicating light sleep. Subjective reports of “dozing off” corroborated these observations. These periods of light sleep, almost devoid of alpha, affected the average alpha ratios.

Subjective reports indicated that the procedure was experienced as either pleasing and relaxing or neutral. Open interviews revealed that one subject who was certain he had found the key and was controlling his alpha was in actuality producing no more EEG alpha than before.

Discussion

Since the procedural conditions of the pilot study were insufficient to document that the alpha binaural beats could stimulate increased alpha, the strategy of adding the biofeedback task was conceived to provide subjects with an ongoing measure of success. It is conceivable that with feedback, subjects will be able to discover successful strategies for letting the binaural beats entrain their brain rhythms to the frequency of the stimulus.

The Study

Based on the results reported in the pilot study, the following study was conducted which incorporates a feedback condition into the binaural-beat procedure. The feedback will theoretically provide the subject a measure of the success with which he or she is allowing the binaural beat to entrain the EEG.

Subjects

Sixty volunteer undergraduate and graduate students from Memphis State University and Christian Brother’s College participated in the study. The students from Christian Brother’s College were volunteers from Jane Davis’ introductory psychology classes. The Memphis State students were from Burl Gilliland’s, Bob Davis’, and Fleetis Hannah’s counseling classes. Participants were screened for known neurological damage and abnormalities.

Instrumentation

The binaural beats were provided by a model 201B Hemi-Sync Synthesizer (“Instruction Manual,” undated). The alpha-frequency binaural beats were created by presenting two pure tones, one to each ear, through a set of headphones, which differed in frequency by 10.5 Hz. The instrument was tested for validity and reliability on an oscilloscope and found to meet adequate standards for both.

EEGs were recorded bipolarly from occipital and temporal sites of both hemispheres (T3, T4, 01, 02 sites as per Jasper, 1958) by a Mind Mirror II EEG (Blundell, undated; Cade & Coxhead, 1979). After recording the EEGs on magnetic tape, the information was converted to digital form and computer analyzed.

Design and Procedure

Sixty subjects received brief relaxation response training based on a handout they were given, and randomly assigned to one of four groups: (a) alpha frequency binaural-beat stimulation, (b) visual, eyes-open alpha brain-wave biofeedback, (c) both alpha-frequency binaural beats and alpha biofeedback, or (d) artificially produced surf sounds. The ratio of males to females was kept constant for all groups.

The procedure for each subject consisted of the following steps: (a) the subject completed a pre- test of subjective mental and physical relaxation, (b) the subject was introduced to the four components of the “relaxation response” (Benson, 1975), (c) the subject was introduced to the stimulus which served as the mental device to theoretically elicit the relaxation response (either alpha binaural beats, alpha biofeedback, both, or phased white noise), (d) the subject was connected to the EEG, (e) the subject was instructed to become comfortable, relax, and breathe slowly and deeply for three to four minutes, (f) a two-minute eyes-open EEG baseline was recorded, (g) the subject was provided with the appropriate stimulus and allowed to become oriented to the situation, (h) the subject engaged in a ten minute eyes-open session of attempting to passively allow the stimulus to serve as the mental device to elicit the relaxation response, (i) the subject was briefly interviewed concerning strategies being used and subjective experience of the procedure and possibly reminded of previously mentioned strategies, (j) the subject engaged in a second ten minute session identical to the first, (k) the subject was disconnected from the EEG, (l) the subject completed the Self-Report Form and was interviewed concerning subjective experience of the procedure.

Data Analysis

Hypotheses H(1), H(2), and H(3) were tested by utilizing a 2 X 4 mixed analysis of variance and appropriate follow-up procedures. The between subjects independent variable was be the specific stimulus used by the subject as a mental device to elicit the relaxation response. The within- subjects variable was the time of the sampling of the alpha production; baseline or treatment sample. The dependent variable was the alpha production of the subject.

Hypothesis H(4) was tested by utilizing a 2 X 4 mixed analysis of variance with appropriate follow- up procedures. The between subjects independent variable was the stimulus used as the mental device and the within subjects independent variable was the time of testing; pre- or post- procedure. The dependent variable was the level of relaxation reported.

Summary

This study attempts to examine the effects of alpha-frequency binaural-beat stimulation combined with alpha-frequency brain-wave biofeedback on alpha production and subjective report of relaxation through the utilization of a 2 X 4 mixed ANOVA design. It seems plausible that the combination of visual alpha feedback and alpha binaural beats will enhance the frequency- following response and assist the subjects voluntarily entrain their cortical rhythms to the stimulus.

Analysis of the Data Demographics of Subject Sample

Sixty volunteer subjects, forty females and twenty males, from various Memphis State counseling classes and from two Christian Brother’s College introductory psychology classes participated in the study. Volunteers from Christian Brother’s College were offered extra credit for their participation. Subjects were solicited by the author to participate in a study of the relaxation response. Age of subjects ranged from eighteen to forty-five with a mean of 27.7, a mode of 19, and a standard deviation of 7.64. Data was gathered between October 6, 1989 and October 21, 1989.

Data Analysis Techniques

Subjects were randomly assigned to four treatment groups of fifteen, each with ten females and five males. Each of the four groups received brief relaxation training followed by one of four treatments, a) alpha-frequency binaural-beat stimulation, b) alpha-frequency brain-wave feedback, c) alpha-frequency binaural beats with alpha-frequency brain-wave feedback, or d) artificially produced ocean surf sounds. Baseline and treatment alpha production ratios were obtained as well as pre- and posttreatment measures of subjective experience of mental and physical relaxation. The data was analyzed using the Statistical Package for the Social Sciences X (SPSSX) analysis of variance and followup procedures (Norusis, 1988). Since the form of the alpha production scores was proportional, arcsine transformations were performed on the alpha ratios prior to analysis in order to promote homogeneity of error variance and normality of error effects and to obtain additivity of effects (Kirk, 1982). For the experimental effects which achieved significance, the omega squared statistic was computed to indicate the strength of the associations (Kirk, 1982).

Assumptions

The mathematical model upon which the SPSSX analysis of variance procedures rest assumes that the error effects are distributed normally in the treatment population, independently determined and distributed in the treatment population, and vary homogeneously in the treatment population. The degree to which these assumptions were met affects the validity of the findings.

Homogeneity of variance

Homogeneity of variance is a major assumption underlying the SPSSX analysis of variance procedures. The Bartlett-Box F test for univariate homogeneity of variance was used as a starting point for testing this assumption. The results of this procedure are reported in Table 1.

Table 1

Bartlett-Box F Test for Homogeneity of Variance

Measure F P

Alpha Production

Baseline 1.109 .344

Treatment 2.305 .075

Relaxation Scores

Pre-test 0.121 .948

Post-test 0.735 .531

The significance levels indicate that there is no reason to reject the hypothesis that the variances in the two groups are equal. However, an additional test which examines the variances and covariances simultaneously is necessary in order to sufficiently test for homogeneity of dispersion (Norusis, 1988).

Homogeneity of dispersion

Homogeneity of dispersion matrices must be considered when using multivariate analysis of variance (Norusis, 1988). Box’s M test is based on the determinants of the variance-covariance matrices in each cell as well as the pooled variance-covariance matrices, thus providing a multivariate test for the homogeneity of the matrices. The results of this procedure are presented in Table 2. As indicated, there appears to be no reason to reject the hypothesis that the variance-covariance matrices are equal across all levels of the between-subjects factors. We can conclude, therefore, that the assumption of homogeneity of variance of the error effects is not violated in this data set.

Table 2

Box’s M Test for Homogeneity of Dispersion

Measure F P

Alpha Production 1.128 .338

Total Relaxation 0.317 .970

Hypothesis 1

It was hypothesized that alpha-frequency binaural- beat-stimulation would increase alpha brain wave production above eyes-open baseline levels.

Table 3 shows the results of the 2 X 4 SPSSX repeated measures ANOVA of alpha production.

Table 3

ANOVA Summary for Alpha Production Ratios

Source SS df MS F

Between .01 3 .003 1.07

Error .20 56 .004

Within .04 1 .04 101.84*

Interaction .01 3 .003 4.16**

Error .02 56 .0004

*p < .01

**p < .05

Between effect showed no significant differences among the groups, indicating that all groups were essentially equal in their baseline alpha production. However, the within effect, the difference between baseline and treatment alpha ratios, was significant (F(1,56) = 101.84; p<.01). Table 4 displays the group means for baseline and treatment alpha production.

Table 4

Mean Alpha Production Ratios

| Baseline | Treatment | Marginal*

Group| Mean SD | Mean SD | Mean

A | .081 (.033) | .114 (.044) | .098

B | .073 (.028) | .092 (.033) | .083

C | .084 (.040) | .134 (.052) | .109

D | .075 (.045) | .127 (.068) | .101

—–+——————+——————–+————

* | .078 (.036) | .117 (.052) | .098

—–+——————+——————–+————

*row and/or column averages

Additionally, a significant interaction effect was found (F(3,56) = 4.16; p<.05), indicating that significant differences were present in cell group means.

Post-hoc analysis was accomplished by the SPSSX one-way analysis of variance follow-up procedure. As demonstrated by Table 5, the treatment alpha production ratio of Group A was found to be significantly higher than the baseline alpha production ratio (F(1,56) = 93.34; p<.01). Thus Hypothesis 1 was not rejected. Omega squared for the effect ( = .613) indicates that we can conclude that the treatment for group A accounts for about 61% of the variance in the alpha production scores.

Table 5

ANOVA Summary for Followup on Group A

Source SS df MS F

Between groups .0327 1 .0327 93.3429*

Error .0196 56 .0004

*p < .01

Hypothesis 2

It was hypothesized that visual eyes-open alpha biofeedback training will increase alpha production above eyes-open baseline levels.

As demonstrated by Table 6, post-hoc analysis reveals that the treatment alpha production ratio of Group B was found to be significantly higher than the baseline alpha production ratio of Group B (F(1,56) = 30.94; p<.01). Thus Hypothesis 2 was not rejected. Omega squared ( = .346) indicates that the treatment accounts for about 35% of the variance in the alpha production scores of Group B.

Table 6

ANOVA Summary for Followup on Group B

Source SS df MS F

Between Groups .0108 1 .0108 30.9429*

Error .0196 56 .0004

*p < .01

Hypothesis 3

It was hypothesized that the combination of visual eyes-open alpha biofeedback training with alpha frequency binaural beats stimulation will interact to increase alpha production more than either technique alone.

As demonstrated by Table 7, post-hoc analysis reveals that the treatment alpha production ratio of Group C is significantly higher than the baseline alpha production ratio (F(1,56) = 214.29; p < .01). Omega squared ( = .785) indicates that the treatment effects account for about 79% of the variance in the alpha production of Group C.

Table 7

ANOVA Summary for Followup on Group C

Source SS df MS F

Between Groups .0750 1 .0750 214.286*

Error .0196 56 .0004

*p < .01

Follow-up analysis of the interactions between groups is displayed in Table 8. As indicated, a significant interaction was found (F(3,112)=2.6914; p < .05).

Table 8

ANOVA Summary for Followup on Interaction

Source SS df MS F

Between Groups .0153 3 .0051 2.6914*

Error .2128 112 .0019

*p < .05

Tukey’s HSD test revealed that the groups which were significantly different at the .05 level were Groups B and C. Omega squared ( = .0417) indicates that the differential treatment of groups B and C accounts for about 4% of the variance between the two groups’ alpha production scores.

Group C did not differ significantly from Group A, thus Hypothesis 3 was rejected.

Hypothesis 4

It was hypothesized the combination of alpha binaural beats with alpha biofeedback would result in increased subjective report of relaxation.

Table 9 displays the results of the 2 X 4 SPSSX repeated measures ANOVA on subjective report of

Table 9

ANOVA Summary for Subjective Report of Total Relaxation

Source SS df MS F

Between 37.67 3 12.56 1.20

Error 585.20 56 10.45

Within 1116.30 1 1116.30 214.97*

Interaction 19.90 3 6.63 1.28

Error 290.80 56 5.19

*p < .01

Between effect showed no significant difference among the groups, indicating that the groups were essentially equal in their pretest scores on subjective report of mental and physical relaxation. However, results also indicated that the within effect, the difference between pre- and post-test scores of mental and physical relaxation, was significant (F(1,56) = 214.97; p<.01). No interaction effect was found. Table 10 provides the means and standard deviations of the pre- and post-treatment scores of relaxations.

Table 10

ANOVA Summary for Mean Subjective Report of Total Relaxation

| Pre-test | Post-test | Margin*

Group| Mean SD | Mean SD | Mean

A | 11.1 (3.62) | 4.07 (1.67) | 7.59

B | 10.2 (3.26) | 4.53 (2.33) | 7.37

C | 11.3 (3.56) | 6.33 (1.76) | 8.82

D | 11.4 (3.16) | 4.73 (2.22) | 8.07

  • | 11.0 (3.40) | 4.92 (2.00) | 7.96

*row and/or column averages

In relation to Hypothesis 4, the post-treatment relaxation scores of Group C were found to be significantly higher than the pre-treatment scores (F(1,56)=144.51; p<.01), resultantly Hypothesis 4 was not rejected. Table 11 displays the results of the follow-up ANOVA on pre- and post-test total relaxation scores. Omega squared ( = .712) indicates that the treatment effects account for about 71% of the variance in the total relaxation scores of Group C.

Table 11

ANOVA Summary for Follow-up on Group C Total Relaxation

Source SS df MS F

Between Groups 750.0 1 750.0 144.5*

Error 290.6 56 5.19

*p < .01

Qualitative Data Gathered

In addition to the quantitative data gathered, anecdotal information was gathered during open interviews which supplements the quantitative data already reported. At the end of the procedure, each subject was uniformly asked, “How was your experience?” Subjects in groups A and C were also asked, “How was your experience of the beats?” Subjects in groups B and C were asked, “How was your experience of the feedback?” and “What strategies were successful in increasing alpha?” Subjects in group C were asked, “Were there any associations between your focus on the beats and your alpha production?” Group D subjects were asked, “How was your experience of the surf sounds?” Information concerning the responses to these questions is reported as it relates to common themes among the groups and differential themes between the groups.

All Groups

The characteristic response of subjects, regardless of the treatment group, was that the experience was enjoyable, pleasant and relaxing. Numerous subjects reported various visual, auditory, tactile or kinesthetic sensations. These sensations are reported in relation to the group or treatment with which they were associated. A number of subjects in all groups reported drowsiness and a desire to close the eyes. Other common themes reported were feelings of peace, calm and tranquility, altered perception of time, feelings of numbness, and disassociation from the body. An additional theme noted in all groups was difficulty eliminating intrusive thoughts.

Associations With the Binaural Beats

Subjects in groups A and C received alpha- frequency binaural-beat stimulation. In response to the question, “How was your experience of the beats?” the following themes were noted: a) the beats were comfortable, pleasant and relaxing, b) felt more physically relaxed when focused on the beats, c) the beat was helpful in eliminating intrusive thoughts and relaxing mentally, d) perception of the beat tended to change in frequency and amplitude, depending on focus e) creative imagery or insights came to mind, f) physical sensations such as bodily warmth or tingling, and g) intracranial sensations, such as feelings of light pressure, especially in the temporal and frontal areas.

Three subjects reported difficulty focusing on the beat. Three subjects with previous meditation experience reported the beats to be more relaxing than other relaxation or meditation strategies. One subject reported that she could use the memory of the beat to recall the feelings she experienced with it.

One subject reported that the color of the visual stimulus seemed to fade when focusing on the tones. The same subject noted a visual perception of a clockwise rotation of the colors green and red at a rate of about two cycles per second.

Two subjects associated the beats with sensations in the sinuses; one reported that the beat caused a pressure build-up while another reported that the beat seemed to cause her sinus drainage to stop. The subject who reported that the beats caused her sinus drainage to stop reported that she “moved it around my body and it stopped my cough and relieved the tension in my neck.”

Associations With Alpha Feedback

Subjects in groups B and C received alpha feedback and were asked how they experienced the feedback and what strategies were helpful in increasing alpha. Subjects generally reported that the feedback was pleasant and interesting. Several also reported that it was difficult not to let the movement of the lights interfere with their efforts to become mentally relaxed.

Themes which surfaced in regard to successful strategies discovered included a) confirmation of oculomotor strategies which affected alpha, b) deep breathing and or exhalation was associated with increased alpha, c) verbal strategies such as affirmations increased alpha, d) mental imagery such as pleasant memories or scenes increased alpha, e) mental effort or thinking decreased alpha, f) alpha increased when momentarily between thoughts, g) alpha increased when focused on the binaural beats, and h) it became easier to control alpha production as the session progressed.

Three subjects reported identifying no successful strategies for increasing alpha and two reported identifying no feelings which corresponded to increased alpha.

Associations With the Surf Sounds

In response to questions regarding experience of the surf sounds subjects unanimously reported positive feelings and associations. There seemed to be a higher level of enthusiasm for the surf sounds than for the binaural beats. One obvious explanation is that surf sounds often are associated with pleasant beach and ocean memories. Several subjects in Group D reported such associations.

Group C

Group C subjects were asked uniformly if they noticed any correlation between their focus on the binaural beat and the movement of the two lights indicating increased alpha. Nine of the fifteen subjects stated in various ways that focusing on the beat was a successful strategy in increasing alpha. The following statements are verbatim reports from four of these subjects:

Subject #53 was observed to have an unusually high alpha production near the end of the session. During the interview he reported to have gained complete control of the lights by his focus on the beats. He stated, “The beat increased slightly in frequency and volume right after alpha increased dramatically. Then I used that memory to make alpha increase again.”

Subject #56 reported that he felt “a moving rolling pressure across the frontal area and then filling both sides as the beats filled my mind and the alpha increased.”

Subject #27 reported “the tones became like a bar in the front of my head and when the bar formed the beat disappeared and the alpha increased.”

Subject #34 reported that she “was able to focus on the lower tone in my right ear and bring it to the other until when they came together and I heard the beat, the alpha lights would go all the way out.”

Summary, Conclusions and Recommendations Summary

The data provides evidence that all groups demonstrated increases in alpha production and subjective experience of both mental and physical relaxation resulting from the treatment procedures. The only interaction found was that of groups B and C. Under the conditions of this study, the combination of alpha-frequency binaural beats and alpha brain-wave feedback resulted in significantly more alpha production than alpha brain-wave feedback alone.

Conclusions

The conclusions that can be drawn from this study are presented as they relate to each hypothesis.

Hypothesis 1

Hypothesis 1, that alpha-frequency binaural beats stimulation would increase alpha brain wave production, was not rejected. However, the increase in alpha production over baseline was due to numerous factors, one of which was the binaural- beat stimulation. The subjects also received brief relaxation response instructions and conditions conducive to relaxation were provided. It should be noted that group A, which received alpha- frequency binaural beats, did not differ significantly in treatment alpha production from Group D, which received artificially produced surf sounds. It cannot be concluded from this data that the increase in alpha for Group A was due to a frequency-following response.

Hypothesis 2

Hypothesis 2, that visual eyes-open alpha- frequency biofeedback training would increase alpha production above eyes-open baseline levels, was not rejected. However, the amount of alpha increase which is due to the biofeedback training as opposed to other treatment effects such as the relaxation-response training or naturally occurring biological rhythms is indeterminable from these results.

Hypothesis 3

Hypothesis 3, that the combination of alpha feedback and alpha binaural beats would interact to increase alpha production more than either technique alone, was rejected. The treatment alpha production of Group C (feedback and beats) was significantly greater than that of Group B (feedback only) but not that of Group A (beats only). Before concluding that the difference between Groups B and C was due to the alpha- frequency binaural beats, it must be noted that the most parsimonious explanation of this difference is that the addition of a pleasant, constant auditory stimulus made conditions more conducive to spontaneous alpha for subjects in Group C. These results do not necessarily lead to the conclusion that the increase in alpha-frequency brain-wave production is due specifically to the presentation of alpha-frequency binaural beats. It should be noted that Group C did not differ significantly in alpha production from Group D, which also received a pleasant, constant auditory stimulus.

A conceptual distinction between spontaneous and evoked cortical potentials is helpful when considering the effects of alpha-frequency binaural beats. Since the human alpha rhythm is a naturally occurring or spontaneous rhythm of the cortex, deciding how much if any of the alpha production was evoked by the alpha-frequency binaural beats is difficult. Due to methodological limitations of this study, it is impossible to state conclusively that any of the alpha production was evoked. It could be argue that the most parsimonious explanation of the difference in alpha production between groups B and C is that group C conditions were more optimal for spontaneous alpha due to the addition of a constant, pleasant auditory stimulus.

It is useful to note that subjects in groups B and C were presented with conditions which usually induce alpha blocking. The alpha feedback was both visual and moving, and subjects were given the tasks of identifying associations with increased alpha and strategies which caused alpha to increase. Given this information–the visual stimuli and complex tasks of these groups–it might be expected that these two groups would produce less treatment alpha than the other seemingly less active groups. Since these two groups produced as much treatment alpha as the other two groups, it could then be argued that these two groups were resultantly more active in their production of alpha than the other two groups. The additional information in the next section concerning the subjective reports of associations made between the beats and alpha production may promote the argument that a significant part of that activity involved, for group C, an active focus on the binaural beats.

Associations Between Alpha Beats and Alpha Production

The subjective reports of associations between alpha production and focus on the alpha frequency beats are not only worthy of note but perhaps the most significant findings of this study. Nine of the fifteen subjects in Group C reported that increased attention to the beats was associated with increased alpha production. One might argue that since this association was implied by the conditions of the treatment, subjects were simply responding to suggestion or expectation effects. However, the detail of the events involved in the association reported by several of the subjects warrants a consideration of the possibility that these subjects did in fact voluntarily self- regulate their own alpha production by their attentional focus on the beats. Another possibility that warrants consideration is that a portion of the alpha production of these subjects was evoked by the alpha frequency binaural beats.

Hypothesis 4

Hypothesis 4, that the combination of alpha binaural beats with alpha biofeedback would result in increased subjective report of relaxation, was not rejected. Evidently the procedure was experienced to be both mentally and physically relaxing. Since there was no interaction among the groups, the beats and feedback procedure was found to be no more relaxing than the other procedures.

Recommendations

The following recommendations are made in regard to the further investigation of the interactions of binaural beats and biofeedback for the purpose of facilitating self-regulation and management of consciousness:

The use of additional beat frequencies and feedback techniques and such methodological refinements necessary to enable more conclusive statements concerning the ability of binaural beats to entrain electrocortical rhythms.

Longitudinal quantification of the effects of binaural-beat techniques on states of consciousness.

The integration of EEG measurement, assessment and feedback wherein naturally occurring rhythms are detected and appropriate binaural beats are fed back which stabilize or enhance a desired indigenous state of consciousness or entrain an otherwise targeted state of consciousness.

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Self-Report Form

Name:                         Date:        Time:

Sex: F     M      Age:      Group: A B C D

Level of Relaxation (pre-procedure):

Mental.

relaxed  1   2   3   4   5   6   7   8   9   10  tense

Physical.

relaxed  1   2   3   4   5   6   7   8   9   10  tense

Level of Relaxation (post-procedure):

Mental.

relaxed  1   2   3   4   5   6   7   8   9   10  tense

Physical.

relaxed  1   2   3   4   5   6   7   8   9   10  tense

Comments

Relaxation Response Handout

The relaxation response is an integrated mind/body reaction which has been found to have such benefits as increased mental and physical health and improved ability to deal with tension and stress. Some physiological components of the response are decreased oxygen consumption, decreased respiratiry rate, decreased heart rate, and increased alpha brain wave production. An individual’s ability to voluntarily control the relaxation response thus enables a degree of control over these bodily processes. Also, gaining voluntary control of these physical processes results in greater control of the general relaxation response.

Herbert Benson in his book The Relaxation Response (1975), surveys some of the major techniques used for eliciting the relaxation response and describes the essential components of these techniques:

A Mental Device. A constant stimulus such as a sound, word, or phrase repeated silently or audibly, or fixed gazing at an object.

A Passive Attitude. If distracting thoughts occur they should be disregarded and one’s attention should be redirected to the technique. One should not worry about how well he or she is doing.

A Relaxed Body. A comfortable position free from muscular stress.

A Quiet Environment. A location free from distracting stimuli.

The research indicates that those individuals who have gained a degree of control over their relaxation response and the accompanying physiological processes through this technique have done so through regular practice. Just like any skill, practice tends to improve performance. Benson recommends that one practice the technique for ten to twenty minutes once or twice per day.

An important component of the ability to voluntarily control the relaxation response is an identification of the subjective feelings associated with it. Once one knows where a place is, getting there becomes easier.

Thanks for volunteering to participate in this study of the relaxation response. I hope you enjoy it as much as I do.