The Effect Of Cognitive Control And Neural Distractor On Inhibition Of Return In Discrimination Tasks

Response to the target at the cued location is slower than that at the uncued location when cue-target SOA (Stimulus Onset Asynchrony) is longer than 250ms. The phenomenon which is called "inhibition of return" (IOR) has been systematically studied by researchers after Posner and Cohen (1984) discovered it. On the base of previous studies, this paper investigated the effect of cognitive control and neutral distractor on IOR in discrimination tasks further.The studies consist of three experiments. In experiment 1 we used two different task demands, examined the effect of top-down cognitive control on location-based and color-based IOR; In experiment 2 we used four different neutral distractors, examined the effect of neural distractor that appeared on different time course on color-based IOR; In experiment 3 we used three different neutral distractors, examined the effect of neural distractor that appeared on different location on location-based IOR.The result showed that the phenomena of color-based IOR happened only asked subjects to manually report the color. Moreover, location-based IOR consistently appeared in both subject tasks even though the subjects were not asked to discriminate the location. It means that the top-down cognitive control is an important factor in the generation of color-based IOR and this also supported the hypothesis of "attention may process location automatically" proposed by Russell. Meanwhile, under the four neural distractor conditions, IOR happened only when the neural distractor appeared on the middle time course of ISI. It means that the time course of ISI when neural distractor appeared is an important factor in the generation of color-based IOR. In experiment 3, the effect of IOR is different when the neural distractor appeared on different locations. It means that the location of neural distractor is an important factor in the generation of location-based IOR.