Abstract
Previous work has shown identical target repetition results in superior search performance (Goldstein & Beck, 2018), a decreased reliance on visual working memory (VWM) as indicated by contralateral delay activity (CDA; Carlisle, et. al., 2011) and possibly, an increased reliance on long-term memory (Woodman, Carlisle, & Reinhart, 2013). However, in the real world, we often have to search for the same category of items rather than the same exact item. For example, an airport security screener needs to repeatedly search for the category of “weapon”. This study evaluated the effect of categorical repetition on search performance and target-related VWM utilization. Participants were cued with two possible targets prior to performing a search task containing one target and five non-target category distractors. Target categories consecutively repeated three to nine times; each target category was presented for two non-consecutive runs of trials. Contrary to identical target repetition findings, there was a speed accuracy trade-off in which search slowed but became more accurate with repetition (both, p< .05), but eye movement measures of search performance showed little effect of repetition. Interestingly, examining target-related CDA over time and repetition revealed a significant interaction (p< .01). Over repetitions, early CDA decreased, whereas late CDA was fairly stable, suggesting that VWM maintenance shortly after preview offset reduced with categorical repetition but later VWM maintenance did not. We speculate that decreased CDA shortly after cue offset may indicate a reduction in feature extraction from the target cue over repetitions. Conversely, the stable presence of CDA in the later time window may be indicative of the maintenance of long-term categorical information in VWM prior to search onset.