Fore-period effect and stop-signal reaction time

The effect of response readiness on the stop-signal reaction time (SSRT) in a stop-signal task was examined, with the stop-signal delay updated following a staircase procedure. We computed SSRT on the basis of a horse race model. A fore-period effect was computed, which described subjects' readiness to respond to the GO signal. The results showed that the fore-period effect correlated positively with SSRT, providing evidence of the effect of response prepotency on stop signal processing. This finding suggests that response readiness needs to be accounted for in examining response inhibition in a stop-signal task.