The presence of a nonresponding effector increases inhibition of return.

Inhibition of return (IOR) refers to the performance disadvantage for targets presented at an exogenously cued location, relative to an uncued location, at relatively long cue-target onset asynchronies. In this experiment, we investigated the influence on IOR of a nonresponding effector (i.e., the index finger of the nonresponding hand) placed on a response key in a simple-RT task. With peripheral cues and targets, IOR and spatial stimulus-response compatibility effects were larger when the nonresponding hand was placed on a response key. IOR--the slowed responding to go signals at the cued location--was accompanied by a lower false alarm rate when no-go signals were presented there. These findings provide direct evidence for a motoric component to IOR wherein some portion of the inhibition is observed as a criterion shift against responding to the cued location.