Galvanic skin response

Galvanic skin response (or GSR), also known as electrodermal response (EDR) or psychogalvanic reflex (PGR), is a method of measuring the electrical resistance of the skin and interpreting it as an image of activity in certain parts of the body. The mapping of skin areas to internal organs is usually based on acupuncture point.

Practice

GSR is conducted by attaching two leads to the skin, and acquiring a base measure. Then, as the activity being studied is performed, recordings are made from the leads. There are two ways to perform a GSR - in active GSR, current is passed through the body, with the resistance measured. In passive GSR, current generated by the body itself is measued.

History

GSR originated in the early 1900s. It was used for a variety of types of research in the 1960s through the late 1970s, with a decline in use as more sophisticated techniques (such as EEG and MRI) replaced it in many areas of psychological research. GSR still sees limited use today, as it is possible to use with low-cost hardware (galvanometer).

Non-research uses

GSR has seen, outside of the research community, usage as a lie detector, under the theory that telling of lies increases perspiration, changing the conductance of skin. Its accuracy, because of its limited scope, is believed to be even less significant than a regular polygraph. GSR is also used by Scientologists, who call their devices E-meters, in their spiritual counseling.

See also

• Electrical quackery
• Electroacupuncture

External links

• University of Kuopio page on GSR Use
• Quack "Electrodiagnostic" Devices by Stephen Barrett, M.D. (a Quackwatch paper)