Prepulse inhibition of perceived stimulus intensity: paradigm assessment.

In 1939, Helen Peak reported that the presentation of paired acoustic stimuli, separated by 177ms, resulted in a 25% reduction in the perceived intensity of the second stimulus. After 65 years, this form of prepulse inhibition of perceived stimulus intensity (PPIPSI) remains relatively less developed, compared to technically and analytically complex "gating" measures, e.g. PPI of startle and P50 event related potential (ERP) suppression. We report that unlike PPI, which can be observed at very brief inter-stimulus intervals (ISI's), PPIPSI requires ISI's >or=60ms. It exhibits significant test-retest stability over a 2-week period, does not exhibit sex differences or menstrual cyclicity, and is not significantly associated with personality dimensions of novelty seeking, harm avoidance, reward dependence or sensation seeking. PPIPSI is a robust, stable, parametrically sensitive and "low tech" measure of sensory gating that is relatively unaffected by a number of biological variables in normal individuals.