(Investigator 129, 2009
The living brain generates minute electrical currents
activity, even in a semi-comatose state. These weak pulsating
electrical currents were discovered by Richard Caton in 1875, and ten
years later, Adolph Beck noticed that the large rhythmic oscillations
apparent when we are relaxed or resting were "blocked", or disappeared
when awake and stimulated. In 1925, Hans Berger, a German psychiatrist,
discovered that these minute currents or brain wave patterns could be
recorded from the brain’s surface by means of small electrodes attached
to the scalp, and using an electroencephalograph and an electromagnetic
pen on continuously moving paper.
In normal adult persons the EEG record is made up of rhythmic
oscillations called alpha, beta, theta or delta
repeated at between 0.5 and 30 Hz. (Hertz = cycles per second.)
Alpha waves (8-12 Hz) are those we are principally concerned with in
connection with biofeedback and are best obtained when a person is
relaxed and with the eyes closed. When the eyes are open or a person is
excited, the waves disappear and are replaced by the low-voltage,
rapid, irregular beta waves.
Observations made in Japan and India of Zen and Yoga meditators showed
much alpha in their EEGs while meditating and the ability to produce
more than normal amounts of alpha with their eyes open.
Because experienced meditators reported a pleasant state of
consciousness, a link was established between alpha waves and the
benefits to be obtained from meditation. It was then argued that if
people could be taught to control their alpha periods by mechanical
means, maximum benefit could be obtained with the minimum effort. The
possibility of achieving a higher state of awareness or "alpha
consciousness" which could be an antidote for stress was appealing, and
Biofeedback apparatus carne into being.
The biofeedback devices are used in a similar way to EEGs, with
electronic sensors attached to the scalp to inform the subject of the
normally imperceptible physiological variations that are taking place,
and which are caused by various brain, muscle and circulatory
Unlike the electroencephalograph, which records the brainwaves
graphically, the home-use biofeedback apparatus consists of
stethoscopic headphones to monitor an audio tone. With this type of
feedback and a little practice it is possible to voluntarily control
these unfelt bodily changes and the alpha waves to advantage. Kits for
building biofeedback monitors have been marketed for as little as $50.
Whilst it is true that alpha waves are the rhythmic pulsations in an
EEG record produced under certain conditions by electrochemical
activity in the cells of the brain, the precise meaning of the alpha
rhythm has not yet been determined by brain researchers. So how does
the claim of the purveyors of feedback devices and "alpha
consciousness" stand up to scrutiny?
The fact that alpha tends to be blocked by opening the eyes gave rise
to the idea that it was inversely related to concentration and led to
the notion that alpha was linked with a transcendent state. The idea
was confirmed after observations of Zen and Yoga meditators in Japan
and India who showed much alpha in their EEGs while meditating.
However, it is a logical mistake to assume that because two things are
correlated, there is cause and effect. Meditation is one of those
states in which people do not process much information, hence the
preponderance of alpha. Trained meditators have developed the ability
to ignore stimuli which usually blocks alpha, but alpha by itself does
not guarantee someone is meditating. While all meditative disciplines
seem about equally related to alpha production they vary considerably
and in some cases, are rejected as being meditative. It has long been
recognized that lower animals also produce alpha but few people would
suggest that animals meditate.
Finally, most people produce alpha when they simply close their eyes
and refrain from active thinking or remembering. A blank mind therefore
It is widely believed, despite these shortcomings, that alpha is
responsible for a self-reported pleasant state of consciousness and
that its control could be beneficial. In 1969, Joe Kamiya reported in Altered
States of Consciousness, that people could learn to
alpha output with feedback. Subjects were presented with an audio tone
whenever an electronic filter detected alpha in their EEGs. They were
told to do whatever they wanted in order to keep the alpha feedback
tone on as much as possible. His subjects reported the experience as
enjoyable and a link between increased alpha and a transcendent state
Rising disillusionment with many conventional beliefs coupled with
questionable advertising touting unsubstantiated scientific claims,
provided the vehicle for commercialism and biofeedback devices stormed
the marketplace. The machines were technically inadequate, as the
electrical signals in the brain are considerably weaker than the
electromagnetic noise that pervades modern buildings, and the EEG can
be swamped by the bio-electrical activity of the muscles, skin, heart,
and eye movements.
Reliable EEG recording requires meticulous care in preparing the skin
to receive the electrodes and fastidious attention must be paid to the
shielding, grounding and filtering of the apparatus, which in hospitals
and laboratories are enormously expensive. Even if the technical
inadequacies of the monitoring apparatus are overlooked, the factors
determining the baseline for later comparison are also critical.
Eyes-closed alpha production is measured at the beginning of a session
as a base line, the task is to do whatever is necessary to produce more
alpha at the end of the session than that of the base line and
eventually exceed the base line with eyes open. To obtain a true
indication of increased alpha production the initial baseline must not
be artificially suppressed. As the conditions prevailing at the onset
of the session are conducive to diminishing alpha, i.e. excitement,
anxiety, anticipation and novelty, the first exposure could initially
depress the alpha baseline. The quieter alpha feedback environment
promotes relaxation and the resulting increase in alpha output gives a
false impression of control.
Why then do recipients of this dubious therapy testify to its efficacy?
Many physical and psychological problems are self-limiting and many
ineffectual treatments coincide with recovery by natural restorative
processes. If any physiologically inert treatment instills the belief
that it will work, it is likely to have positive spin-offs. It is known
as the "placebo effect". Melzack and Wall, in The Challenge of Pain
(1982), conclude that biofeedback was "not found to be superior to less
expensive, less instrument-oriented treatments such as relaxation and
coping-skills training." Its limited value is seen as a distracter —
essentially a mechanical placebo.
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Addison-Wesley. Reading, Mass.
Brown, B. 1974. New Mind. New Body. Harper & Row. NY.
Melzack, R. & Wall P. 1982. The Challenge of Pain. Penguin.
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