Short History of Light and Sound Therapy

by Michael Hutchison

To those seeing them for the first time, sound and light devices may seem
bizarre, like something out of a science fiction movie--the users seem laid back, out
there somewhere, wired into a small box listening through headphones to some
unheard sounds while eerie light pulsations flicker inside futuristic goggles. And to
those encountering these devices from a background of meditative practice, the idea
that one can attain heightened or meditative states of consciousness by using a
machine, and the sheer technical computerized hardware of the devices themselves,
must seem coldly materialistic. But while the hardware may seem new, the
techniques being used are ancient.
The knowledge that a flickering light can cause mysterious visual hallucinations
and alterations in consciousness is something humans have known since the
discovery of fire. It must have been knowledge of great value to the ancient shamans
and poets, who learned how to use the images in the flames to enhance their magic.
Ancient scientists were also intrigued by this phenomenon, and explored its practical
applications. In 125 A.D. Apuleius experimented with a flickering light stimulus
produced by the rotation of a potter's wheel, and found it could be used to reveal a
type of epilepsy. Around 200 A.D. Ptolemy noted that when he placed a spinning
spoked wheel between an observer and the sun, the flickering of the sunlight through
the spokes of the spinning wheel could cause patterns and colors to appear before
the eyes of the observer and could produce a feeling of euphoria.
Light researcher David Siever has found that in the 17th century, a Belgian
scientist, Plateau, used the flickering of light through a strobe wheel to study the
diagnostic significance of the flicker fusion phenomenon. As he caused the light
flickers to come faster and faster, he found that at a certain point the flickers seemed
to "fuse" into a steady, unflickering light pattern. Plateau discovered that healthy
people were able to see separate flashes of light at much higher flicker speeds than
were sick people. (In recent years, studies using light sources such as a
tachistoscope to provide rapid light flashes have revealed that long-term meditators
are able to see discrete flashes of light at much higher flicker rates than nonmeditators.)
At the turn of the century, French psychologist Pierre Janet noticed that
when patients at the Salpetriere Hospital in Paris were exposed to flickering lights
they experienced reductions in hysteria and increases in relaxation.
Similarly, humans had always been enthralled by the effects of rhythmic
sounds, and aware of the mind-altering and brain wave entrainment effects of
rhythmic noises, as evidenced for example by the sophisticated auditory-driving
techniques developed over thousands of years by shamans and priests. As
anthropologist and shamanism authority Michael Harner, points out, "Basic tools for
entering the SSC [Shamanic State of Consciousness] are the drum and
Researcher Andrew Neher investigated the effects of drumming on EEG
patterns in the early 1960s and found the rhythmic pounding dramatically altered
brain wave activity. Other researchers of shamanistic rituals, Harner observes, have
"found that drum beat frequencies in the theta wave EEG frequency range . . .
predominated during initiation procedures."
And humans have always been keenly appreciative of the consciousnessheightening
powers of music, which is of course, among other things, a succession of
rhythmic auditory signals. For thousands of years musicians and composers have
consciously and intentionally influenced the brain states of listeners by manipulating
the frequency of the rhythms and tones of their music.
Humans have also long been intrigued by the possibilities for influencing mental
functioning that emerge from combining both rhythmic light and rhythmic sound
stimulation. Ancient rituals for entering trance states often involved both rhythmic
sounds in the form of drumbeats, clapping or chanting, and flickering lights produced
by candles, torches, bonfires or long lines of human bodies rhythmically dancing,
their forms passing before the fire and chopping the light into mesmerizing rhythmic
flashes. Some composers of the past, such as the visionary Scriabin, actually created
music intended to be experienced in combination with rhythmic light displays.
Technological advances made possible even more powerful combinations of
sound and light. Moving pictures developed
Modern scientific research into the effects of rhythmic light and sound began in
the mid-1930s when scientists discovered that the electrical rhythms of the brain
tended to assume the rhythm of a flashing light stimulus, a process called
entrainment. Research shifted into high gear in the late 1940s when the great British
neuroscientist W. Gray Walter used an electronic strobe and advanced EEG
equipment to investigate what he called the "flicker phenomenon." He found that
rhythmic flashing lights quickly altered brainwave activity, producing trancelike states
of profound relaxation and vivid mental imagery. He was also startled to find that the
flickering seemed to alter the brain-wave activity of the whole cortex instead of just
the areas associated with vision. Wrote Walter: "The rhythmic series of flashes
appear to be breaking down some of the physiologic barriers between different
regions of the brain. This means the stimulus of flicker received by the visual
projection area of the cortex was breakiing bounds--its ripples were overflowing into
other areas." The subjective experiences of those receiving the flashes were even
more intriguing: "Subjects reported lights like comets, ultra-unearthly colors, mental
colors, not deep visual ones."
Walter's research aroused the attention of many artists, including the American
novelist William Burroughs, and they put together a simple flicker device called the
Dreammachine. As Burroughs described it in the 1960s, "Subjects report dazzling
lights of unearthly brilliance and color. . . . Elaborate geometric constructions of
incredible intricacy build up from multidimensional mosaic into living fireballs like the
mandalas of Eastern mysticism or resolve momentarily into apparently individual
images and powerfully dramatic scenes like brightly colored dreams."
A flood of subsequent scientific research in the 1960s and 70s revealed that
such flicker effects at certain frequencies seemed to have amazing powers. Various
scientists discovered that such photic stimulation could have a variety of beneficial
effects, such as increasing I.Q. scores, enhancing intellectual functioning and
producing greater synchronization between the two hemispheres of the brain. Other
researchers found that the addition of rhythmic auditory signals dramatically
increased the mind-enhancing effects.
Throughout history technological advances, such as those in cinema, have
quickly been seized upon to stimulate the human fascination with rhythmic sound and
light. Throughout the 1970s and early 1980s, technological advances also made it
possible for scientists to understand more fully how sounds and lights influenced the
electrochemical activity of the brain. The result was the flood of studies mentioned
above, dealing with photic and auditory entrainment, and hemisperic synchronization.
In the early 1970s, Jack Schwarz, known for his feats of self-healing and selfregulation,
began selling a device known as the ISIS, which used varible frequency
lights mounted in goggles combined with rhythmic sounds to produce heighted
mental states. In 1973, scientist Richard Townsend published a description of his
research with a device using goggle-mounted lights for photic entrainment. In 1974 a
scientist at City College of New York, Seymour Charas, obtained the first patent on a
combined sound and light stimulation device, though it was never put into
commercial production. But by the early 1980s the time was right for a breakthrough
in the combination of sound and light.
The catalyst was the revolution in microelectronics that was taking place at that
time, a revolution that allowed home electronics buffs and garage inventors to put
together astonishingly sophisticated and complex devices for producing and
combining sound and light—devices that could produce a rich assortment of tones,
chords and even beat frequencies; that permitted the selection of a variety of lightflash
patterns and intensities; that enabled the user to select the mode of interplay
between lights and sound; that contained a number of preset “programs” designed to
produce specific states of consciousness, ranging from sleep to meditation to extreme
alertness, at the push of a button; and that permitted the users to design and store
in the device’s computerized memory a variety of their own programs. Before the
breakthroughs in microelectronics, such complex computerized devices would have
been enormously expensive to build, and like the old UNIVAC vacuum-tube
computers, their circuitry and components would have been huge and unwieldy. But
these new sound and light stimulators were relatively small—some of the first models
were about the size of a portable typewriter; soon models were being made with
consoles not much bigger than a pack of cigarettes.
As happened with personal computers, there seem to be new advances, new
machines, and new generations of older devices appearing almost constantly; and as
with PCs, the advances have included smaller size, greater versatility and power, and
steep reductions in price. As this is written, there are well over 20 sound and light
machines in commercial production around the world, and we seem on the verge of
an entirely new generation of devices that combine sound and light stimulation with
biofeedback capabilities. These new devices enable the machine to read the user's
dominant brainwave activity, and then provide the optimal frequency of sound and
light to entrain brainwave activity toward the "target" frequency. One such device
(the DreamWave) is already on the market.
Another significant development is the advent of a sound and light system on a
simple board that can be plugged into your computer's expansion slot. One example
currently on the market is the MindsEye Synergizer, a hardware-software
combination that turns an IBM PC XT/AT/386 or clone into a research laboratory
grade audio-visual synchronizer, permitting users to program hundreds of sessions of
almost any length and complexity, to program each eye and ear independently (this
permits extraordinary effects, such as combining alpha and theta frequencies, or
setting up visual "beat frequencies"), create sounds, chords and beat frequencies on
the computer with a stereo synthesizer, and program thousands of time ramps and
sound-light levels into a single session.
These developments point the way toward the future. I believe it will be only a
short time until we have a fully computerized integrated and interactive system that
would allow the user to put on a few electrodes that would monitor EEG as well as
other physiological indicators (muscle tension [EMG], skin potential, heart rate, skin
temperature, breathing, etc.) and display them on the computer screen in real time;
would use this information to provide the optimal type of sound and light stimulation
(as well as cranial electrostimulation and appropriate digitized music selections or
preprogrammed audio suggestions, hypnotic inductions, information for accelerated
learning, etc.); and would permit the storage of thousands of sessions, with
individual users able to select desired mind states or experiences with the ease of
selecting a channel on the TV, or play back or re-experience past sessions. The
technology for such a system is already available.
It has been well established that these devices can rapidly produce states of
deep relaxation, and may increase suggestibility, receptivity to new information, and
enhance access to subconscious material. New work into the effects of these devices
being undertaken around the world, and preliminary results suggest that the
machines may of being beneficial in the treatment of migraine headaches and
learning disorders, alleviation of pain, enhancement of immune function, and much
more. Here's a summary of some of the most interesting work done in the last
In one preliminary 1980 study of one of the sound and light machines, Dr.
Thomas Budzynski, then of the Behavioral Medicine Associates clinic in Denver, found
that "Results ranged from production of drowsy, hypnagogic-like states (with theta
frequency used), to vivid, holograph-like images. At times, images from childhood
were experienced." This led Budzynski to speak of the device as a "Hypnotic
Facilitator," and a "Facilitator of 'Unconscious Retrieval," that could have therapeutic
value, since the device seemd "to allow the subject to recall past childhood events
with a high degree of 'being there' quality." He also suggested that the device could
be effective for accelerated learning, since it seemed capable of putting users in the
theta (or "twilight state") of hypersuggestibility and heightened receptivity to new
Medical researcher Dr. Gene W. Brockopp of Buffalo, New York, speculated that
sound and light stimulation could perhaps "actively induce a state of deactivation in
which the brain is passive, but not asleep; awake, but not involved with the 'clutter'
of an ongoing existence. If this is true, then it may be a state in which new cognitive
strategies could be designed and developed." Brockopp also suggested that "If we
can help a person to experience different brain-wave states consciously through
driving them with external stimulation, we may facilitate the individuals' ability to
allow more variations in their functioning through brreakup up patterns at the neural
level. This may help them develop the ability to shift gears or 'shuttle' and move
them away from habigt patterns of behavior to become more flexible and creative,
and to develop more elegant strategies of functioning."
In 1988, anethesiologist Robert Cosgrove Jr., Ph.D., M.D., undertook
preliminary studies of sound and light stimulation. In his initial evaluations, in which
he used the Alpha-Pacer II device, Cosgrove, an authority in pharmaceutics and
biomedical engineering, noted that audio-visual stimulation was "clearly very
powerful in its ability to cause deep relaxation in most subjects. Its effectiveness has
been so great that we are very enthusiastic about the prospect of evaluating the
[device] for its sedative properties in patients prior to, during, and immediately
following surgery. We are also undertaking studies to prove [its] utility in chronic
"We are also," Cosgrove continued, "quantitating the electroencephalographic
(brainwave, EEG) effects… in both volunteers and patients. Our preliminary results
show strong EEG entrainment.”
The device, Cosgrove noted, "with appropriately selected stimulation protocols
has been observed by us to be an excellent neuropathway exerciser. As such we
believe it has great potential for use in promoting optimal cerebral performance. . . .
Furthermore, the long-term effects of regular use of the device on maintaining and
improving cerebral performance throughout life and possibly delaying for decades the
deterioration of the brain
In 1989, another researcher, D.J. Anderson, used photic stimulation using red
LED goggles to treat seven sufferers of migraine headaches--none of whom had been
able to relieve their migraines with drug treatments. He found that out of 50
migraines noted, 49 were rated by subjects as being "helped," and 36 sttopped by
the photic stimulation. Significantly, brighter lights were found to be more effective.
Further evidence of the potential therapeutic value of photic stimulation has
come from researcher Jill Ammon-Wexler, Ph.D., of the Innerspace Biofeedback and
Therapy Center in Los Gatos, CA, using a device that uses a flickering light stimulus
without an accompanying sound stimulus. The device, called a Lumatron, uses a
strobe light with color filters to provide rhythmic photic stimulation in variable
frequencies and in selected wavelength or color bands [MEGABRAIN REPORT will
devote a full-length article to this device in a future issue]. Ammon-Wexler did a
controlled study of twenty subjects suffering from phobias and found that
"remarkable resolution of the subjects' phobic systems had occurred over the process
of the 20 experimental sessions. There was also 'across the board' evidence for
enhanced self-concept, and clinically-significant reductions in both anxiety and
Dr. Ammon-Wexler's findings about the potential medical benefits of photic
stimulation have been echoed recently by William Harris, M.D., director of the Penwell
Foundation, an organization for the investigation, research and application of
different modalities for the treatment of those with AIDS/HIV. In preliminary work
with a number of AIDs sufferers he has experimented with the use of a sound and
light machine (the IM-1) and found it extremely effective. He speculates it may boost
immune function by producing states of deep relaxation, by enhancing the patients'
receptivity to suggestions for healing, by improving patients' ability to visualize and
the clarity of their visualizations. "At this point it's conjecture," says Harris, "But I
think that this type of machine may actually be stimulating . . . the body to produce
its own chemical substances," and that these natural substances may enhance
immune function and healing.
In 1990 Bruce Harrah-Conforth, Ph.D., of Indiana University completed a
controlled study of one of the computerized sound and light machines (the MindsEye
Plus) the result of over two years of research into the field of brain entrainment, and
found that compared to the control group, which listened to pink noise with eyes
closed, the group receiving sound and light stimulation showed dramatic alterations
in their EEG patterns responding to the frequency of the sound and light device, and
also showed evidence of hemispheric synchronization. Participants in the study were
asked to describe their experiences. According to Dr. Harrah-Conforth, "the subjects'
comments were such typical descriptions as 'I lost all sense of my body,' 'I felt like I
was flying,' 'I was deeply relaxed,' 'I felt like I was out of my body,' etc."
The report by Harrah-Conforth suggests that sound and light devices may
cause simultaneous ergotropic arousal, or arousal of the sympathetic nervous system
and the cerebral cortex, associated with "creative" and "ecstatic experiences," and
trophotropic arousal, or the arousal of the parasympathetic system, associated with
deep relaxation and "the timeless, 'oceanic' mode of the mystic experience." In
humans, Dr. Harrah-Conforth concludes, "these two states may be interpreted as
hyper- and hypo- arousal, or ecstasy and samadhi."
In a separate letter to MEGABRAIN REPORT, Harrah-Conforth writes: "I have
little doubt that brain entrainment technology is a highly effective means of inducing
changes in consciousness." He continues, "Brain entrainment, at least within my own
research, has shown itself to be virtually foolproof and does indeed facilitate whole
brain experiences." While pointing out that our current understanding of brain
entrainment technology is only in its infancy, he writes "there seems to be little doubt
that this technology has a remarkable future. The evidence, my own and others,
clearly indicates that brain-wave entrainment is produced by these machines. EMG
tests have also made it quite clear that one of the byproducts of this entrainment can
be the relaxation response. And subjective reports range from heightened creativity,
to beautiful visual trips, to increased alertness, and many other states." He
concludes that "the early indications are strong that this now-developing technology
will profoundly revolutionize both our concepts of, and interaction with, our
consciousness. . . . The evolution of human consciousness is a tangibly manipulable
process. We can control our destiny. . . . It would appear as though brain
entrainment will be among the technologies leading the way."
California psychologist Julian Isaacs, Ph.D., working with a private research
group called "The Other 90 Percent," is now engaged in an ongoing study of the
brain-wave effects of sound and light as well as other mind-altering devices.
Megabrain, Inc. is providing assistance in this research by, among other things,
making available a number of devices. Isaacs and his colleagues are using a 24
electrode color brainmapping EEG, with newly developed software that permits
extremely precise and sensitive measurement and statistical analysis of whole brain
electrical activity. In a discussion of his preliminary findings, he told me that there
was "very clear evidence of brainwave driving" using sound and light. He also said
he'd found a very strong correlation between the intensity of the lights used (whether
red LEDs or incandescent bulbs) and the brain-entrainment: the brighter the lights,
the more entrainment. He mentioned one device he had tested that used dim lights,
and found it had "no brain driving capacity at all."
However, Isaacs pointed out that it was easiest to entrain brain-wave activity in
the alpha range, while it seems much more difficult to drive the slower brain
frequencies, such as theta (a fact discussed by the machine manufacturers in the
roundtable discussion elsewhere in this issue). However, the EEG evidence was quite
clear that people using the devices did indeed spend much of their sessions in theta.
Often, however, their dominant theta frequency was very different from the theta
frequency being flashed by the sound and light machine. How to explain this? Isaacs
suggested the possibility that while the devices can clearly and quickly entrain
brainwave activity into the low alpha range, what happens next is that the brain
becomes habituated to the repetitive stimulus and the Reticular Activating System--
the volume control and attention-directing part of the brain--simply tires of the
repetitive stimulus and ignores it, or "blanks out" the conscious perception of the
lights. As a result, the brain drops into the theta state.
The effect, that is, may be very much like that of the ganzfeld, which uses a
featureless and unvarying visual field to cause the "blank out" effect. This theory
brought to my mind the work of Dr. Gene Brockopp mentioned above, who suggested
that sound and light stimulation could perhaps "actively induce a state of deactivation
in which the brain is passive, but not asleep; awake, but not involved with the
'clutter' of an ongoing existence. If this is true, then it may be a state in which new
cognitive strategies could be designed and developed."