Stimulus versus response decisions as determinants of the relative frequency effect in disjunctive reaction-time performance.

Abstract

In a typical disjunctive reaction-time (DRT) task, one cannot separate the relative contributions of stimulus and response events to decisions underlying performance. In the present study, use of a conditional DRT technique permitted independent variation of stimulus and response frequencies. The effects of these variations on response latency and GSR were studied in 4 experiments, on a total of 96 Ss[subjects]. An inverse relation between RT (and GSR) and frequency of the response alternatives, but not of the corresponding stimulus alternatives, was demonstrated. It is suggested that models of DRT performance should stress response-selection, rather than stimulus-identification, factors in decision processing.