The effects of brief variable foreperiods on simple reaction time

Abstract

Highly practiced subjects responded to a visual stimulus that was presented with a probability of 1.00 (no catch trials) or 0.90 (catch trials) after one of five randomly determined brief fore-periods (300, 400, 500, 600, or 700 msec). Mean reaction time decreased linearly under the no catch-trials condition and curvilinearly under the catch-trials condition, as a function of increasing foreperiod duration. The results were consistent with the hypothesis that reaction time covaries with the momentary probability of occurrence of the response signal. Specifically, an increase in this momentary probability leads to an increase in the subject’s readiness to detect the signal. Because performance was virtually errorless, it appears that any concomitant tendency to anticipate the signal can be successfully inhibited. © 1989, Psychonomic Society, Inc.. All rights reserved.