(Investigator 129, 2009 November)

The living brain generates minute electrical currents during its 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 waves regularly 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 activities.

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 constitutes meditation.

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 enhance 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 was presumed.

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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[From: A Skeptic's Guide to the New Age, H Edwards]