Galvanic Skin Response (GSR)
One of the first references describing the use of GSR instruments in psychoanalysis is in the book by Carl Gustav Jung, entitled "Studies in Word Analysis", published in 1906. Here the Swiss psychologist describes a technique of connecting the subject, via hand-electrodes, to an instrument measuring changes in the resistance of the skin. Words on a list were read out to the subject one by one. If a word on this list was emotionally charged, there was a change in body resistance causing a deflection of the needle of the galvanometer. (reference)
Any words which evoked a larger than usual response on the meter were assumed to be indicators of possible areas of conflict in the patient, and these areas were then explored in more detail with the subject in session. Jung used observed deflections on the meter as a monitoring device to aid his own judgment in determining which particular lines of enquiry were most likely to be fruitful with each subject.
Without amplification, this device was difficult to use, thus it remained as little more than a laboratory curiosity until the development of sophisticated valve amplifiers in the 1930s. Once a portable psycho-galvanometer with amplification was available, the idea of using a psycho-galvanometer was picked up with enthusiasm by criminologists. These meters became known as "lie detectors", and have been used by various police forces, in this manner, for more than 60 years. On the other hand, little further work was done in psychotherapy with the psycho-galvanometer, until Biofeedback Research in the 1970s using the psycho-galvanometer in connection with meditation and relaxation became popular.
Biofeedback is the technique of self-regulation of awareness states by the subject. The level of cortical arousal is central to a person's level of awareness, so a machine that can measure this factor is of the first importance in biofeedback. Many papers have been presented on this subject over the last 25 years, and the most important findings of this research are:
Volney Mathison was a pioneer in the discovery that all fears, feelings, resentments,thoughts, and emotions were electrical in their nature. Mathison found through experiments with lie-detectors during the 1940s that when a person was reminded of certain past events, or when a change of mood was induced in him, the needle in the meter would jump erratically. The degree of jump was in proportion to the strength of unconscious reaction. In skilled hands the meter could be used to locate a particular mental content, the nature of that content, the location of that content in space and time, and the amount of force contained within it.
His researches with lie-detectors in the 1940's made it possible for Mathison to invent the modern type of portable transistorized GSR meter, a type that has survived with very little change, until the present day. Mathison went on to develop a word-list to be used in conjunction with the GSR meter. He would ask the subject under analysis, to take hold of the meter-electrodes, then he would read this list of words to him. Without fail, some of these words would trigger a response on the meter, and in some cases violently. Whenever this was the case, Mathison knew that these words were associated with violent and negative fear or resentment that had its origin in unconscious (reactive) complexes in the subject's mind. Most of the time, the subjects were completely unaware that they were reacting on the meter in this way.