Stimulus intensity and information processing

Abstract

The physiological and behavioral literature regarding effects of stimulus intensity on the time course of information processing is reviewed. The physiological data describe intensity effects on the sensory pathway. Reaction time studies show that the effect of intensity on behavioral responses also depends on and may be mediated by more cognitive processes. The degree to which intensity affects simple reaction time varies directly with the response criterion subjects use. The lack of this dependence in choice reaction time may indicate different intensity effects on energy and nonenergy pathways. The literature suggests that intensity affects the time course of information processing not only by influencing the speed of processing in sensory pathways, but also by affecting alertness and the time required to direct attention to a stimulus.