The inhibitory effect of a recent distracter

Abstract

A series of experiments were conducted to examine the inhibitory effect of a visual distracter on saccadic eye movements. Participants were presented with a sequence of two critical displays. In one display a red target was presented together with a green distracter. This was followed by a display with a new red target presented in isolation at one of three locations with respect to the previous display. The lone target was presented either at the location of the recent target, the location of the recent distracter, or a new location. Participants were instructed to fixate the target in both displays and to ignore the green distracter. Experiment 1 revealed a significant increase in saccadic reaction times (SRTs) when the target was presented at the location of the recent distracter. Experiment 2 revealed that SRTs increased only in the conditions where the new target was presented at the location of the recent distracter, irrespective of its colour. Experiment 3 found that the inhibitory effect lasted for at least 2 s. In Experiment 4 the inhibitory effect was abolished when a lone distracter (i.e., anti-target) was presented without a target. Experiments 5 and 6 revealed that inhibition at the location of the recent target ('inhibition-of-return') also emerged with a shorter inter-display interval and when the distracter was removed from the recent display. These results distinguished between inhibition of a recent distracter and 'inhibition-of-return' and are consistent with models of competitive interactions which generate inhibitory effects on the spatial representation of a distracter.