2010 年 28 巻 2 号 p. 221-231
In general, a visual search for a target that is determined by the conjunction of features becomes inefficient (Treisman & Gelade, 1980). However, Watson and Humphreys (1997) discovered that a search became efficient when half of the distracters were previewed (preview effect). Moreover, Braithwaite, Humphreys, and Hodsoll (2003) found that the preview effect was weakened when the previewed stimuli and the target had the same color (negative carryover). They suggested that there was inhibition which was based on the features of the previewed stimuli, and that the inhibition was generalized to the target. We conducted two experiments to examine whether there is category-based inhibition. The preview effect was observed in both experiments. Also, there was a category-based negative carryover when the target category could not be anticipated (Experiment 2) but with anticipation this phenomenon was eliminated (Experiment 1). The results suggest that, depending on the task setting, category-based negative carryover can occur. However there is a possibility that the effect could be observed with any other factor, rather than the generalization of inhibition.