The impact of multiple irrelevant visual events at the same spatial location on inhibition

If an irrelevant visual event, such as a nonpredictive cue, is presented prior to a target, performance is impaired when the target appears at the cued location relative to when it is presented at an uncued location. This phenomenon, referred to as inhibition of return, can be found at multiple spatial locations when each is cued in succession. The present study examined the effect of successively cuing the same spatial location. Results suggested that additional inhibition occurred when more than one cue appeared at a single location at longer intercue intervals, but not at shorter intervals. These findings suggest that total inhibition to respond to targets at a spatial location reflects a summation of facilitatory and inhibitory factors generated by the presentation of each cue.