SEX-DIFFERENCES IN TEMPORAL SUMMATION BUT NOT SENSORY-DISCRIMINATIVE PROCESSING OF THERMAL PAIN

Gender differences in experimental pain sensitivity have been widely i nvestigated, and the results generally indicate that females exhibit g reater sensitivity to noxious stimuli than males. However, results usi ng thermal pain procedures have been inconsistent, with some studies r eporting greater responses among females and other studies reporting n o gender differences. The present study investigated gender difference s in thermal pain perception using several different psychophysical pr ocedures. Twenty-seven females and 22 males underwent thermal testing, including: determination of thermal pain threshold and tolerance, a t hermal discrimination procedure, real-time magnitude estimates of heat pulses, and temporal summation of thermal pain. The results indicated lower thermal pain threshold and tolerance and greater temporal summa tion of thermal pain among females, but no gender differences in therm al discrimination or real-time magnitude estimates of discrete heat pu lses. These findings suggest that gender differences in thermal pain p erception may be more robust for sustained, temporally dynamic thermal stimuli with a strong C-fiber component. (C) 1998 International Assoc iation for the Study of Pain. Published by Elsevier Science B.V.