Human eccrine sweat gland activity and palmar electrical skin resistance

Sweat gland activity, monitored as a function of the rate at which water vapor was removed from the skin surface (EWL), was measured simultaneously with electrical skin resistance (ESR) from adjacent 1-cm2 areas on the human palm. Both ESR and EWL, and Delta ESR and Delta EWL, were correlated throughout 20–30 min of testing during which the subject rested or participated in conversation. The ratio Delta ESR/Delta EWL was greater the lower the EWL level. As EWL approached diffusion levels (0.06 mg/min.cm2), ESR assumed the highest and most stable value (ca. 170 kilohms). Subject differences in ESR at high EWL rates and the pattern of ESR-EWL relationships through the range of sudomotor activity (0.06–0.18 mg/min.cm2) are attributed to individual variation in the density and activity of sweat glands on the palmar surface. The character of ESR-EWL correspondence was also seen to vary with the phase of sweating activity for any one subject. evaporative water loss; physiological testing; galvanic skin reflex; psychological testing; psychogalvanic reflex; sweat measurement Submitted on October 22, 1964