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September 8, 1962

Differential Diagnosis Between Psychogenic and Physical Pain: The Conditional Psychogalvanic Reflex as an Aid

Author Affiliations

From the Department of Psychiatry, Tufts University School of Medicine, and the Neurobiologic Unit, Division of Psychiatric Research, Boston State Hospital.

JAMA. 1962;181(10):855-861. doi:10.1001/jama.1962.03050360041008

Observations of skin resistance were made on a test group of 20 patients whose chief complaint was pain and on a contratest group of 14 consecutive patients free from pain. The results indicated that in psychogenic pain the spontaneous fluctuations (expressed in ohms per minute) were smaller than the responses to electrical stimulation of a finger (unconditional psychogalvanic reflex) and smaller than the responses to a tone announcing the electrical stimulus (the conditional psychogalvanic reflex). In physical pain, with demonstrated pathological basis, the spontaneous fluctuations were greater than the responses to the electrical stimulus and to the tone announcing the stimulus.