Galvanic Skin Response (GSR)

GSR-built in ITP
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GSR Meter
The simple psycho-galvanometer was one of the earliest tools of psychological research. A psycho-galvanometer measures the resistance of the skin to the passage of a very small electric current. It has been known for decades that the magnitude of this electrical resistance is affected, not only by the subject's general mood, but also by immediate emotional reactions. Although these facts have been known for over a hundred years and the first paper to be presented on the subject of the psycho-galvanometer was written by Tarchanoff in 1890, it has only been within the last 25 years that the underlying causes of this change in skin resistance have been discovered.

The Tarchanoff Response is a change in DC potential across neurones of the autonomic nervous system connected to the sensori-motor strip of the cortex. This change was found to be related to the level of cortical arousal. The emotional charge on a word, heard by a subject, would have an immediate effect on the subject's level of arousal, and cause this physiological response. Because the hands have a particularly large representation of nerve endings on the sensori-motor strip of the cortex, hand-held electrodes are ideal. As arousal increases, the "fight or flight" stress response of the autonomic nervous system comes into action, and adrenaline causes increased sweating amongst many other phenomena, but the speed of sweating response is nowhere near as instantaneous or accurate as the Tarchanoff response.

The most advanced layers of the cortex, unique to Man, link to the thumb and forefinger especially, and there is a further complex physiological response which occurs when the forebrain is aroused. Changes in Alpha rhythms cause blood capillaries to enlarge, and this too affects resistance.

By virtue of the Galvanic Skin Response, autonomic nervous system activity causes a change in the skin's conductivity. The overall degree of arousal of the hemispheres, and indeed the whole brain, is shown by the readings of the GSR psychometer, which does not differentiate between the hemispheres, or between cortical and primitive brain responses. Higher arousal (such as occurs with increased involvement) will almost instantaneously (0.2 - 0.5 sec) cause a fall in skin resistance; reduced arousal (such as occurs with withdrawal) will cause a rise in skin resistance.

Thus a rise or fall relates directly to reactive arousal, due to re-stimulation of repressed mental conflict. Initially this may cause a rise in resistance as this emerging, previously repressed, material is fought against. When the conflict is resolved, by the viewing of objective reality - the truth of exact time, place, form and event - there is catharsis and the emotional charge dissipates; the release of energy giving a fall in resistance.

The Being or "Higher Self" is involved, because it is the Being that knows the objective truth and therefore is in conflict with distorted mental contents. The Being, however, is not part of the brain; it is a quality not a quantity, and is essentially not anywhere, except by consideration. The Being is a non-verbal knowingness that lies back of mental awareness and activity, but which is capable of influencing the composite human being, through will and creative choice, by postulate.

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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:

A low level of cortical arousal is desirable for relaxation, hypnosis, and the subjective experience of psychic states and unconscious manifestations.
A high level of cortical arousal gives increased powers of reflection, focused concentration, increased reading speed, and increased capacity for long-term recall.
Cortical arousal has a simple relationship to skin conductivity. Arousal of the cortex increases the conductivity of the skin and conversely, a drop in arousal causes a drop in skin conductivity. With a sensitive meter the level of arousal can be brought under conscious control. With a few hours' practice the level of arousal can be consciously controlled over wide limits.

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It has long been known in biofeedback research, that meditation and relaxation procedures cause a rise in skin resistance. It has therefore been assumed that high and low skin resistance correlate directly with relaxation and stress respectively, and that a high resistance indicates a pleasant relaxed state of mind, whereas low resistance indicates tension. However, the reverse is true in a psychotherapy session. When repressed material is coming to the surface (e.g. material associated with guilt or pain), the skin resistance rises and the client experiences feelings of tension; thus in a therapy session, high skin resistance indicates tension, and not relaxation as in meditation. Then, when the repressed material reaches the surface and the negative emotion discharges, there is usually a sudden large drop in skin resistance and the client experiences relief. This demonstrates a correlation between low skin resistance and relaxation of tension, which is in contradiction to the pattern of research findings in meditation.

This contradiction has been noted by Dr. Apter of Bristol University in his book "Reversal Theory". He refers to this as Paradoxical Arousal. His discoveries are that high arousal can be pleasant and exciting when a person is in the (active) Paratelic state, whereas high arousal is experienced as unpleasant in the (thinking) Telic state.

Apter's findings are that a person with a heavy traumatic history experiences high arousal as unpleasant, because the cortical arousal is unequal due to restimulation. It can be demonstrated in many cases that one hemisphere is aroused more than the other, as seen on the Bilateral Meter (a special type of differential GSR meter using twin double-electrodes). In contrast, when cortical arousal is uniform this is experienced as a pleasant state of high energy (the Bilateral meter reflects this).

This is similar to Freud's early findings, that high arousal in a neurotic is experienced as internal excitement, which is unpleasant, whereas a person who is substantially free from neurosis experiences arousal as energy for incitement, i.e. energy for action. Our findings substantiate Freud's early findings. Proportional to a client's erasure or transcendence of traumatic material there is an increased capacity to operate at high arousal, in a relaxed state without discomfort, and at a high emotional tone.

In order to resolve the paradox, I suggest that it would be more effective to correlate high and low skin resistance, not with "relaxation" and "stress" but with "withdrawal and "involvement" respectively; both these terms can refer either to a relaxed or to a tense state. The state of withdrawal is relaxed when it means detachment from worldly cares or abandoning responsibility (Telic); and withdrawal is experienced as tense when it means an inability to confront repressed material (Paratelic).

Involvement is experienced as tense when it means over-reach or anxiety (Telic), and is experienced as relaxed when it means enhanced awareness, or when there is a flash of insight and the sudden clearing away of a mental blockage caused by repressed material (Paratelic). A client who is involved in the session of analysis will be in the Paratelic state; if he goes "out-of-session" this will be a reversal to the Telic state:

It is for the above reasons that a fall of the meter needle, i.e. an increase in arousal, is usually more useful than a rise, i.e. a decrease in arousal, when a list is being assessed to find a case entry point - the most appropriate item to handle. Usually, unless the arousal is too high due to overwhelm or terror, the fall of the needle indicates involvement, hence increased awareness and the ability to access and confront charged material. However, when the needle rises in response to a particular word or concept, this indicates withdrawal; it indicates in most cases that the client does not wish to take responsibility for this area of address.


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