Audio-Visual Entrainment, History and Physiological Mechanisms

Audio-Visual Entrainment, History and Physiological Mechanisms - by Dave Siever

Copyright 2006. Reproduction of this				following exposure to AVE at 7.8 Hz.
material is allowed as long as it is
unaltered and complete with Mind Alive				Figure 9. Forearm EMG Levels During AVE
contact information. Reproduction for				(Hawes, 2000)
marketing purposes is prohibited without
permission from Mind Alive Inc.				*** For the complete article with figures
				included, please see... ***
History
				Figure 10. Peripheral Temperature Levels
Clinical reports of flicker stimulation				During AVE (Hawes, 2000)
appear as far back as the dawn of modern
medicine. It was at the turn of the 20th				*** For the complete article with figures
century when Pierre Janet, at the				included, please see... ***
Salpêtrière Hospital in France, reported
that when he had his patients gaze into the				Neurotransmitters
flickering light produced from a spinning
spoked wheel in front of a kerosene lantern,				There is evidence that blood serum levels of
it lowered their depression, tension and				serotonin, endorphine, and melatonin rise
hysteria (34). Then, in 1934, Adrian and				considerably following 10 Hz., white-light
Matthews published their results showing that				AVE (42). Increases in endorphines reflect
the alpha rhythm could be "driven" above and				increased relaxation while increased
below the natural frequency with photic				norepinephrine along with a reduction in
stimulation (1).				daytime levels of melatonin, indicate
				increased alertness (Figure 11).
This discovery further propagated dozens of
small physiological outcome studies on the				Figure 11. Neurotransmitter Levels Following
"flicker following response" by many well				AVE (42)
respected researchers (4,5,11,20,18,22,43).
However no one considered the subjective and				*** For the complete article with figures
behavioral effects of photic stimulation.				included, please see... ***
Finally in 1956, W. Gray Walter published the
results on thousands of test subjects				Dendritic Growth
comparing flicker stimulation with the
subjective emotional feelings it produced				There is evidence that stimulating neurons
(46).				with mild electrical stimulation promotes
				growth of dendrites and dendritic shaft
Meanwhile, William Kroger accomplished other				synapses in the cells being stimulated (6,
important developments in photic stimulation.				25). However, studies do not yet exist on the
Kroger was a physician investigating why				influence of AVE on dendritic growth,
radar operators were going into trances in				although it is suspected because many people
front of their radar sets and of course,				with autism, palsy, stroke and aneurysm (36)
leaving the ship or plane at great risk to				have gained significant motor and cognitive
the enemy. He concluded that the rhythmic				function following a treatment program of
"blip" of the radar was "pulling" the radar				AVE.
operators into a trance state. These findings
compelled Kroger to team up with Sydney				Cerebral Blood Flow
Schneider of the Schneider Instrument Company
of Ohio to construct and market the first				Cerebral blood flow (CBF) is essential for
electronic clinical photic stimulator, called				good mental health and function. SPECT and
the "Brainwave Synchronizer." It comprised of				FMRI imaging of CBF show that hypoperfusion
an intense xenon strobe light complete with a				of CBF is associated with many forms of
rotating dial that could be set to the				mental disorders. CBF increases dramatically
frequencies of the standard four brain wave				during AVE (12, 39). Figure 18 shows an
rhythms. They found the Brainwave				increase of 28% in cerebral blood flow within
Synchronizer had powerful hypnotic qualities				the striate cortex, a primary visual
and soon published a study on hypnotic				processing area within the occiput. As an
induction (24). They also prompted other				interesting note, maximal CBF occurs at 7.8
studies involving hypnotic induction in				Hz, the Schumann Resonance of the earth.
surgery and dentistry, and studies of general
interest to the hypnosis profession (38, 31,				Figure 12. Cerebral Blood Flow at Various
29).				AVE Repetition Rates (12)

In 1981, my wife, Nancy, and I incorporated				*** For the complete article with figures
Comptronic Devices Limited, with a focus on				included, please see... ***
designing TENS units and EMG feedback devices
for dental (TMJ) applications. In 1984, I				Following Fox and Raichle's study was a whole
designed the "Digital Audio-Visual				head PET analysis of visual entrainment at 0,
Integration Device" (DAVID1), used for				1, 2, 4, 7, and14 Hz (32). This study on 19
hypnotic induction and to calm anxiety in				healthy, elderly (mean age=64 years) subjects
performing arts students at the University of				found that regional cerebral blood flow
Alberta. The "light and sound" (L&S) market				(rCBF) was activated differentially with the:
at this time was in its infancy and resided
primarily within the new age sector. There				1) left anterior cingulate showing maximal
was little "known" research to support L&S				increases in rCBF at 4 Hz.
technology, and professionals by and large
showed disinterest. Due mainly to poorly				2) right anterior cingulate showing decreases
designed L&S products and a lack of research,				in rCBF with frequency.
about 40 L&S companies have come and gone,
most of them during the 1980s and 1990s.				3) left middle temporal gyrus showing
However, since the time of Adrian and				increases in rCFB at 1 Hz.
Matthews, a considerable number of studies
have verified photic and auditory "driving"				4) striate cortex showing maximal rCBF at 7
of the EEG. I have since re-named this				Hz.
phenomenon as "audio-visual entrainment" or
AVE, as any given frequency of stimulation				5) lateral and inferior visual association
that is reflected in brain wave activity and				areas showing increases in rCBF with
observable on an EEG or QEEG can be				frequency.
entrained. Many more studies on photic or
combined audio/photic stimulation exist than				While there may be benefits to increasing
pure audio stimulation studies, however				occipital CBF, there is even greater concern
audio-only stimulation studies have confirmed				regarding conditions involving hypoperfuson
audio entrainment (8) and its effect on				of CBF in frontal regions. Frontal disorders
calming masseter muscle tension (30).				include: anxiety, depression, attentional and
				behavior disorders, and impaired cognitive
Physiology of Audio-Visual Entrainment				function (2). Figure 13 shows an increase in
				frontal CBF recorded on Hershel Toomin's
In order for entrainment to occur, a				"Thinking Cap" (or "Hemoencephalogram") using
constant, repetitive stimuli of sufficient				infra-red light to measure perfusion of CBF.
strength to "excite" the thalamus must be				Notice that CBF at FPZ increases by 15% in 10
present. The thalamus then passes the stimuli				minutes (Toomin, personal communication).
onto the sensory-motor strip, the cortex in
general and associated processing areas such				Figure 13 Hemoencephalographic Measure of
as the visual and auditory cortexes. Figure 1				Cerebral Blood Flow During 10 Hz AVE
shows the visual pathway with the retina of
both eyes becoming excited and sending pulses				*** For the complete article with figures
down the optic nerve, through the optic				included, please see... ***
chiasm, and into the lateral geniculate of
both thalami. From here, the visual signals				Normalized EEG Activity
are passed onto the visual and cerebral
cortexes for further processing. Notice that				Figure 14 shows a fairly typical brain map in
there is very little delay from the onset of				1 Hz bins of a person with mild depression
the flash to the response in the optic nerve,				and anxiety as shown on the Skil database.
but a delay of approximately 100 msec occurs				Notice that alpha is slowed and approaching
by the time the visual evoked potential (VEP)				+2SD from the norm and that some beta
is elicited in the visual cortex. This delay				frequencies (16-18 Hz) are high (>1SD) in
may be why entrainment occurs best at the				central frontal areas.
natural alpha frequency -- as 100 msec
equates to 10 Hz.				Figure 14. Brain Map in 1 Hz Bins of
				Individual with Depression and Anxiety
Figure 1. The EEG Photic Stimulation Path				(SKIL-Eyes Open)

*** For the complete article with figures				*** For the complete article with figures
included, please see... ***				included, please see... ***

Photic entrainment begins its process as a				Following an AVE session of 7.8 Hz., both
series of overlapping evoked potentials (23).				alpha and beta activity are normalized as
Kinney broke down a simple VEP into its				shown below in Figure 15.
various components (Figure 2) representing
the passage of time for 4, 8, 12 and 20 Hz.				Figure 15. Brain Map Following 7.8 Hz AVE
As can be seen, much of the VEP occurs within				(SKIL-EO)
250 msec, correlating to four Hz. The various
overlapping parts were then vector summed				*** For the complete article with figures
into the mathematical VEP and compared with				included, please see... ***
the actual VEPs observed by EEG at the
higher, entrained frequencies, shown in				Conclusion
Figure 2.
				In closing, AVE has the ability to quickly
Figure 2. EEG Wavelet				and effectively relax people out of high
				sympathetic activation and traumatic states
*** For the complete article with figures				of mind, bringing a return to homeostasis.
included, please see... ***				AVE may be used alongside hypnotic
				suggestions on tape/CD or live via a
When this mathematical model was compared				microphone. At the same time however, AVE
with the actual observed EEG of the entrained				exerts a powerful influence on brain/mind
stimuli (Figure 3), a high degree of				stabilization and normalization. At the end
predictability was observed, demonstrating				of an AVE session, the user may realize that
that photic entrainment is indeed a vector				he/she has not felt so relaxed for years --
summation of VEPs and not a novel neuronal				perhaps not since childhood.
process.
				Footnote:
Figure 3. EEG VEPs - Vector Addition
(theoretical) Model vs Observed EEG				1. For more information, address all
				correspondence to:
*** For the complete article with figures
included, please see... ***				David Siever, c/o Mind Alive Inc., 9008 - 51
				Avenue, Edmonton, Alberta, Canada, T6E 5X4
By definition, entrainment occurs when an EEG
reflects the brain wave frequency duplicating				Toll Free: (800) 661-6463 Fax: (780)
that of the stimuli, be it audio, visual or				461-9551 Web:
tactile (41). Entrainment occurs best near
one's own natural alpha frequency (43, 23).				Email: References
LEDs and xenon strobe lights contain much
harmonic content due to the "squareness" or				1) Adrian, E. & Matthews, B. (1934) The
rapid turn-on and turn-off transitions of the				Berger rhythm: Potential changes from the
stimuli and these harmonics are reflected				occipital lobes in man. Brain, 57, 355-384.
within the EEG. Figure 4 shows a strong and
pure entrainment at 12 Hz. The harmonics				2) Amen, D. (1998). Change your brain, change
(small wavelets) seen in the EEG are a				your life. New York: Three Rivers Press.
reflection of the actual harmonics contained
within the stimulus. Square wave stimulation				3) Barlow, J. (1960). Rhythmic activity
is associated with an increased risk of				induced by photic stimulation in relation to
seizure (21, 37). The only way to produce				intrinsic alpha activity of the brain in man.
entrainment without harmonics is via sine				Electroencephalography and Clinical
wave stimulation in which the stimuli turn on				Neurophysiology, 12, 317-326.
and turn off in slow, gentle transitions and
do not contain harmonics. (45, 44, 35, 41).				4) Bartley, S. (1934). Relation of intensity
				and duration of brief retinal stimulation by
Figure 4. EEG Showing Photic Entrainment				light to the electrical response of the optic
				cortex of the rabbit. American Journal of
*** For the complete article with figures				Physiology, 108, 397-408.
included, please see... ***
				5) Bartley, S. (1937). Some observations on
AVE at 18.5 Hz has also been shown to produce				the organization of the retinal response.
dramatic increases in EEG amplitude at the				American Journal of Physiology, 120, 184-189.
vertex (14), where it was found that:a)
eyes-closed 18.5 Hz. photic entrainment				6) Beardsley, T. (1999, June). Getting
increased 18.5 Hz EEG activity by 49%.b)				wired. Scientific American, 24-25.
eyes-open auditory entrainment produced
increased 18.5 Hz. EEG activity by 27%.c)				7) Brownbeck, T. & Mason, L. (1999).
eyes-closed auditory entrainment produced				Neurotherapy in the treatment of
increased 18.5 Hz EEG activity by 21%.d)				dissociation. In J. R. Evans, & A. Arbanel.
eyes-closed AVE produced increased 18.5 Hz.				(Eds.), Introduction to quantitative EEG and
EEG activity by 38.3%.				neurofeedback (pp 145-156). San Diego:
				Academic Press.
Entrainment primarily shows itself frontally
and near the vertex (41). Figure 5 is a QEEG,				8) Chatrian, G., Petersen, M. & Lazarte, J.
or "brainmap" from the SKIL (Sterman-Kaiser				(1959). Response to clicks from the human
Imaging Labs) database, in 1Hz bins showing				brain: Some depth electrographic
the frequency distribution of AVE at 7.8 Hz.				observations. Electroencephalography and
The area within the circle at 8Hz shows				Clinical Neurophysiology, 12, 479-489.
maximal effects of AVE in central, frontal
and parietal regions (at 10uv in this case)				9) Dempsey, E. & Morison, R. (1942). The
as referenced with the oval area on the				interaction of certain spontaneous and
legend. It is through these effects that AVE				induced cortical potentials. American Journal
has proven effective in treating depression,				of Physiology, 135, 301-307.
anxiety and attentional disorders. A harmonic
is also present at 16 Hz. (the circled				10) Donker, D., Njio, L., Storm Van Leewan,
image), which is typical of semi-sine wave				W., & Wieneke, G. (1978). Interhemispheric
(part sine/part square wave) stimulation.				Relationships of Responses to Sine Wave
				Modulated Light in Normal Subjects and
Figure 5. Brain Map in 1Hz Bins -- During				Patients. Encephalography and Clinical
7.8 Hz AVE (SKIL-Eyes Closed)				Neurophysiology, 44, 479-489.

*** For the complete article with figures				11) Durup, G. & Fessard, A. (1935).
included, please see... ***				L'electroencephalogramme de l'homme (The
				human electroencephalogram). Annale
Body/Mind Effects of Audio-Visual Entrainment				Psychologie, 36, 1 -32.

We conceptualize AVE as achieving its effects				12) Fox, P. & Raichle, M. (1985). Stimulus
through several mechanisms at once (40).				rate determines regional blood flow in
These include:				striate cortex. Annals of Neurology, 17, (3),
				303-305.
1) dissociation / hypnotic induction,
				13) Fox, P., Raichle, M., Mintun, M., &
2) increased neurotransmitters,				Dence, C. (1988). Nonoxidative glucose
				consumption during focal physiologic neural
3) possible increased dendritic growth,				activity. Science, 241, 462-464.

4) altered cerebral blood flow, and				14) Frederick, J., Lubar, J., Rasey, H.,
				Brim, S., & Blackburn, J. (1999). Effects of
5) normalized EEG activity.				18.5 Hz audiovisual stimulation on EEG
				amplitude at the vertex. Journal of
Dissociation				Neurotherapy, 3 (3), 23-27.

Dissociation is described as a process where				15) Glista, M.D., Frank, M. D., & Tracy, M.
feelings, memories and physical sensations				D. (1983). Video games and seizures. Archives
are kept apart from other information that				of Neurology, 40, 588.
would normally be logically associated. In
pathological terms, dissociation is a				16) Glicksohn, J. (1986-87). Photic driving
maladaptive disruption in integrated				and altered states of consciousness: An
functioning typically associated with				exploratory study. Imagination, Cognition and
depersonalization, stress, identity, amnesia				Personality, 6 (2), 1986-87.
and depersonalization disorders (7).
				17) Goldberger, L. (1982). Sensory
On the other hand, dissociation occurs when				deprivation and overload. Handbook of Stress,
we meditate, exercise, read a good book, take				The Free Press, New York, 410-418.
in a movie or enjoy a sporting event, because
we get drawn into the present moment and				18) Goldman, G., Segal, J., & Segalis, M.
dissociate from all of our daily hassles,				(1938). L'action d'une excitation
worries, anxieties and the resulting				inermittente sur le rythme de Berger. (The
unhealthy mental chatter. Several techniques				effects of intermittent excitation on the
such as dot staring and stimulus depression				Berger rhythms (EEG rhythms). C.R. Societe de
have been shown to induce dissociation (26).				Biologie Paris, 127, 1217-1220.
Audio dissociation analgesia using white
noise has been shown to effectively increase				19) Hear, J. (1971). Field dependency in
pain threshold and pain tolerance during a				relation to altered states of consciousness
dental procedure (33).				produced by sensory-overload. Perception and
				Motor Skills, 33, 192-194.
Regardless of the activity, this type of
dissociation reduces our weekly stress load,				20) Jasper, H. H. (1936). Cortical excitatory
whether we are aware of it or not. In				state and synchronism in the control of
essence, when we focus on something, we				bioelectric autonomous rhythms. Cold Spring
dissociate from other things. The saying, "a				Harbor Symposia in Quantitative Biology, 4,
change is as good as a rest," has much more				32-338.
truth to it than initially meets the eye
(40).				21) Joyce, M. & Siever, D. (2000).
				Audio-visual entrainment program as a
The first study on dissociation induced via				treatment for behavior disorders in a school
entrainment involved hypnotic induction and				setting. Journal of Neurotherapy, 4 (2) 9-25.
found that photic stimulation at alpha
frequencies could easily put subjects into				22) Jung, R. (1939). Das Elektroencephalogram
hypnotic trances (24, 29). Figure 6 shows				und seine klinische Anwendung.(The
the results of Kroger and Schneider's study				electroencephalogram and its clinical
in which nearly 80% of the participants in				application). Nervenarzt, 12, 569-591.
the study were in a hypnotic trance within
six minutes of photic entrainment.				23) Kinney, J. A., McKay, C., Mensch, A., &
				Luria, S. (1973). Visual evoked responses
Figure 6. Photic Stimulation Induction of				elicited by rapid stimulation.
Hypnotic Trance (24)				Encephalography and Clinical Neurophysiology,
				34, 7-13.
*** For the complete article with figures
included, please see... ***				24) Kroger, W. S. & Schneider, S. A. (1959).
				An electronic aid for hypnotic induction: A
Psychologists have been looking for ways to				preliminary report. International Journal of
dissociate their clients as a part of fear				Clinical and Experimental Hypnosis, 7, 93-98.
and phobia treatment. Inducing dissociation
using AVE delivered by the DAVID1 was found				25) Lee, K., Schottler, F., Oliver, M., &
to be more effective than dot staring or				Lynch, G. (1980). Brief bursts of
stimulus deprivation (26) as shown in Figure				high-frequency stimulation produce two types
7.				of structural change in rat hippocampus.
				Journal of Neurophysiology, 44 (2), 247-258.
Figure 7. AVE Induced Dissociation (26)
				26) Leonard, K., Telch, M., & Harrington, P.
*** For the complete article with figures				(1999). Dissociation in the laboratory: A
included, please see... ***				comparison of strategies. Behaviour Research
				and Therapy, 37, 49-61.
Furthermore, Leonard completed a second study
with people who experience dissociative				27) Leonard, K., Telch, M., & Harrington, P.
anxiety (27). People with dissociative				(2000). Fear response to dissociation
anxiety feel a need to have a sense of				challenge. Anxiety, Stress and Coping, 13,
control in their lives and become anxious or				355-369.
panicky when they dissociate, be it driving
home, at the office, or in a clinical				28) Lipowsky, Z. (1975). Sensory and
setting. The Acute Dissociation Inventory				information inputs over-load: behavioral
(ADI) is a 35-item self-report scale (26). It				effects. Comprehensive Psychiatry, 16,
assesses dissociative sensations (ADI-Dissoc)				199-221
and subjective anxiety, or dissociative
anxiety in response to dissociative				29) Lewerenz, C. (1963). A factual report on
provocation (ADI-Anx). Leonard and her				the brain wave synchronizer. Hypnosis
colleagues clinically dissociated people who				Quarterly, 6 (4), 23.
become anxious when dissociating, by using a
DAVID Paradise HemistepTM alpha session. As				30) Manns, A., Miralles, R., & Adrian, H.
expected, the participants' anxiety (ADI-Anx)				(1981). The application of audiostimulation
had almost doubled by the end of the AVE				and electromyographic biofeedback to bruxism
session. The surprise, however, was that				and myofascial pain-dysfunction syndrome.
their heart rate actually decreased, contrary				Oral Surgery, 52 (3), 247-252.
to normal anxiety reactions (Figure 8). With
the ability to clinically dissociate these				31) Margolis, B. (1966, June). A technique
people, yet simultaneously calm them down				for rapidly inducing hypnosis. CAL (Certified
somatically, AVE can be used as a				Akers Laboratories), 21-24.
desensitization tool for reducing
dissociative anxiety.				32) Mentis, M., Alexander, G., Grady, C.,
				Krasuski, J., Pietrini, P., Strassburger, T.,
Figure 8. Dissociative Anxiety and Somatic				Hampel, H., Schapiro, M. & Rapoport, S.
Arousal (27)				(1997). Frequency variation of a
				pattern-flash visual stimulus during PET
*** For the complete article with figures				differentially activates brain from striate
included, please see... ***				through frontal cortex. Neuroimage, 5,
				116-128.
A dissociative mindstate or hypnotic trance
may be described in terms of an altered state				33) Morosko, T. & Simmons, F., (1966). The
of consciousness (ASC) in which the subject				effect of audio-analgesia on pain threshold
(or an independent observer of the subject)				and pain tolerance. Journal of Dental
observes a qualitative shift in the normal				Research, Vol 45, 1608-1617.
pattern of mental functioning (16). ASCs
produced via overstimulation also occur when				34) Pieron, H. (1982). Melanges dedicated to
a person is bombarded with higher than normal				Monsieur Pierre Janet. Acta Psychiatrica
levels of sensory input, usually in more than				Belgica, 1, 7-112).
one sensory modality (19, 28, 17). Glicksohn
studied photic entrainment and the ASCs				35) Regan, D. (1966). Some characteristics
produced. He monitored the EEGs of subjects				of average steady-state and transient
during photic entrainment. They all described				responses evoked by modulated light.
a wide variety of reactions to the				Electroencephalogy and Clinical
stimulation with some reporting incredible				Neurophysiology, 20, 238-248.
imagery consisting of items they had seen
before in their lives, intertwined with				36) Russell, H. (1996). Entrainment combined
geometrical patterns while others reported no				with multimodal rehabilitation of a
visual changes at all. At the end of the				43-year-old severely impaired postaneurysm
study, Glicksohn concluded that:				patient. Biofeedback and Self Regulation,
				21, 4.
1) It is the increase in alpha activity
created by photic driving, and not the				37) Ruuskanen-Uoti, H. & Salmi, T. (1994,
natural alpha activity itself, that is				January). Epileptic seizure induced by a
conducive to an ASC.				product marketed as a "Brainwave
				Synchronizer." Neurology, 44, 180.
2) The appearance of visual imagery is
neither necessary nor all that is involved to				38) Sadove, M.S. (1963, July). Hypnosis in
indicate the experience of an ASC.				anaesthesiology. Illinois Medical Journal,
				39-42.
3) If a photic driving response is not
elicited, the subject will not experience an				39) Sappey-Marinier, D., Calabrese, G., Fein,
ASC.				G., Hugg, J., Biggins, C., & Weiner, M.
				(1992). Effect of photic stimulation on human
Glicksohn's observations support the concept				visual cortex lactate and phosphates using 1H
that in order for AVE to occur, the				and 31P magnetic resonance spectroscopy.
stimulating frequency must have a direct				Journal of Cerebral Blood Flow and
impact on brain wave frequency and be				Metabolism, 12 (4), 584-592.
observable on an EEG.
				40) Siever, D. (2000). The rediscovery of
Dissociation and Restabilization				audio-visual entrainment technology.
				Unpublished manuscript.
Dissociating clients with trauma histories,
during the course of treatment is important.				41) Siever, D. (2002). New technology for
The state of mind that a person has at any				attention and learning. Unpublished
given moment is made up of the brainwave				manuscript.
activity associated with apprehension,
anxiety, physical tension (proprioceptive				42) Shealy, N., Cady, R., Cox, R., Liss, S.,
afferent associations), destructive thoughts,				Clossen, W., & Veehoff, D. (1989). A
and conditioned responses relating to the				comparison of depths of relaxation produced
colors, smells, sounds, etc. Once the mind is				by various techniques and neurotransmitters
clear, all of these tensions, conditioned				produced by brainwave entrainment. Shealy and
responses (bracing habits), fearful thoughts				Forest Institute of Professional Psychology.
and the effects of afferance (sensory				A study done for Comprehensive Health Care,
information) subside, allowing the mind and				Unpublished.
brain to relax, become more malleable and
open to new healthy thoughts, post-hypnotic				43) Toman, J. (1941). Flicker potentials and
suggestions, brainwave activity and so on.				the alpha rhythm in man. Journal of
During AVE, the EMG and electro-dermal				Neurophysiology, 4, 51-61.
responses fall, finger temperature increases
and breathing becomes smooth and				44) Townsend, R. (1973). A device for
diaphragmatic. These changes reflect a return				generation and presentation of modulated
to homeostasis or restabilization, hence the				light stimuli. Electroencephalography and
term dissociation and restabilization (DAR)				Clinical Neurophysiology, 34, 97-99.
(40).
				45) Van Der Tweel, L. & Lunel, H. (1965).
Figure 9 shows a typical reduction in forearm				Human visual responses to sinusoidally
EMG and Figure 10 shows a typical increase in				modulated light. Encephalography and Clinical
finger temperature. Notice that				Neurophysiology, 18, 587-598.
restabilization begins after about six
minutes of AVE, when the user begins				46) Walter, W. G. (1956). Color illusions and
dissociating. Figure 11 shows normalization				aberrations during stimulation by flickering
of breathing and heart rate variability				light. Nature, 177, 710.

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Different types of psychology

Audio-Visual Entrainment, History and Physiological Mechanisms - by Dave Siever