The straightforward Skin Resistance galvanometer was one of the earliest electronic tools used in psychological research. One of the first references to the use of this device in psychoanalysis is in a book entitled iStudies in Word Analysis! by Carl Gustav Jung, published in 1906. Here the famous Swiss Psychologist describes a technique for connecting a subject to an instrument, which measured changes in the resistance of the skin while words are read to him from a prepared list. If one of these key words were emotionally charged, through past associations with trauma, whether consciously remembered or buried in the sub-conscious, there would be a change in body resistance measured by a deflection of the meter needle of the galvanometer.
By the 1930's, when valve amplifiers came into use, the psychogalvanometer was adapted for use with pen recorders and became a powerful tool in the hands of the Police as a iLie Detector!. After the 2nd World War it was popularised by the C.I.A. and the United States Police forces as the Polygraph. But even in these applications it was only detecting emotional arousal as an adjunct of lying. People with abnormal psychoses would not give accurate readings under interrogation because of the pressure of internal, mental activity, which masked the external word stimuli.
Since 1950 the stigma of iLie Detection! has gradually been overcome and psychoanalysts have more extensively used the psychogalvanometer as a means of monitoring mental arousal and states of relaxation. Latterly it has come to be used by a subject to monitor himself, with the intention of controlling these mental states consciously. Such techniques can be classified under the general heading of Biofeedback.
As a result of a variety of interacting physiological processes, the complexities of which would fill another book, a change in the state of arousal of the human brain will cause a change in the electrical resistance of the skin. The greatest degree of change occurs in the skin of the palms of the hands, as this is a measure of the large volume of the motor cortex involved with hand and finger movement, the delicacy of touch and sensation required for manual skills and pain reception. The second most sensitive area is the soles of the feet. A rise in cortical arousal will lower the resistance of the skin in these areas, mainly through increased activity of the sweat glands, but also connected with the activation of certain pathways known as acupuncture points. The acidity of perspiration interacts with the metal electrodes, usually copper or silver, to produce small electrode potentials. This is known as the Tarchinoff effect. Conversely a state of relaxation will produce heightened resistance to electrical current. All this is called the simple Galvanic response and until now has been the most commonly exploited physiological process for the purpose of psychoanalysis.
Several researchers have noted in passing that one side of the body gives different responses to the other. See Reid and Inbau (1964). No one bothered to investigate this phenomenon however, with the exception of a little known Czech, Vilem Laufberger. He was a cardiologist by profession, and for cardiology one uses an instrument not unlike a psychogalvanometer. (A very sensitive psychogalvanometer will react to heartbeat by a slight movement of the needle). With a specially constructed instrument Laufberger monitored the resistance changes of the body from four pick-up points, namely, the soles of the feet and both palms. He found that the greatest change would occur at the place in the body where the subject concentrated their attention. For example, if the subject were told to concentrate on their left foot, the reading for this electrode would show the greatest change. Though this experiment was duly reported, its true significance was not grasped at the time.
The simple galvanic response is a raising or lowering of the body resistance as a whole, as a result of general cortical arousal. In analogy this may be compared with the opening or closing of the whole hand. The selective arousal reported by Laufberger corresponds to a differentiated movement of just one or two fingers of the hand.
The fact that movement of the subject's attention to different parts of the body could cause selective arousal of a particular part of the cerebral cortex and a localised change in body resistance is reminiscent of the intuitive Yogic practice of instructing a pupil to focus attention on the particular Chakras, or energy centres in the body, the stomach, spleen, heart, throat, brow and crown.
The point of using a Bilateral Psychogalvanometer, or differential Meter for short, is that there is a need to be able to measure this selective state of cortical arousal, and in particular, to monitor the differential arousal of the two hemispheres of the neo-cortex. The left hemisphere of the brain generally controls the right hand side of the body, and the right hemisphere the left hand side. This means that, as Laufberger discovered, attention to the left of the body will cause a fall in resistance on that side because the state of arousal in the right hemisphere of the brain is greater.
Of itself, such a discovery is of no great significance. However, if one takes into consideration the fact that the left hemisphere of the cortex usually controls speech, logical action and symbolic functions, while the right hemisphere is responsible for spatial and holistic processes, there is a value in having a simple device to facilitate cognitive growth through the technique of biofeedback.
With this very simple device certain complex phenomena can be easily and clearly measured, whereas previously such results could only be obtained with an expensive and sophisticated Electroencephalograph, which made a detailed analysis of brain rhythms recorded by electrodes pasted at different locations on the scalp. The precise significance of the different brain rhythms is still a matter of conjecture, while the overall arousal is a more definite index of activity, usually linked with a rise in temperature.
The following Chapters will describe in detail the functions and applications of the BPG device. It will then be evident that this meter constitutes something of a breakthrough in simple bio-monitoring equipment, bringing sophisticated psychoanalytical and mind development techniques within the reach of the training and teaching professions.
There has been a further new development, which enables the high-frequency variations of body resistance to be analysed by computer and used to present an averaged frequency spectrum of the subject. The frequency of these variations is far higher than can be accounted for by the actions of the nerves. Nevertheless, the energy peaks on this frequency spectrum can be seen to vary from person to person and may be found to relate to physical and mental functions in a very definite way. This technique was first discovered by Valerie Hunt of UCLA in connection with Electromyography (1976 The Infinite Mind).
A survey of the energy fields of a number of different people has been conducted both in Britain and the United States to refine the relationship of the energy peaks that are observed and see if they can be correlated with personality traits and professional ability. The early results are quite promising and a broad band of interpretations can be derived, which will be further defined by more energy field measurements. The discovery of these discrete peaks in the human energy field will come as no surprise to those who follow the disciplines of Yoga.
They will have no difficulty in identifying such frequencies as the successive centres of the Chakras, or vortices by which energy is transmitted from the aether to maintain the human body. The tiny electrical effects are merely the correlate of a much greater force which otherwise exists in a medium beyond the limits of our normal physical world.
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