Abstract
Typically, whenever one task requires more attention, performance on a second task suffers. However, although target detection exerts greater attentional demand than distractor rejection, target detection enhances, rather than impairs memory for concurrently presented and unrelated scenes (the attentional boost effect). To better understand the nature of this enhancement, we examined whether increasing the perceptual and cognitive load of the detection task decreases the magnitude of the attentional boost effect. In several experiments participants pressed a button whenever a particular target symbol appeared in a stream of other colored symbols. At the same time, a series of scenes appeared behind the symbols. We manipulated perceptual load by varying the perceptual similarity between the target and distractor symbols. Participants responded more slowly to targets that were perceptually similar to distractors than to targets that were not. However, the attentional boost effect was equally robust for these two types of targets, suggesting that it overcomes the negative effects of increasing perceptual load. In contrast, increasing cognitive load had clear detrimental effects on the attentional boost effect. When participants had to keep the two most recent target letters in memory, rather than the most recent target letter, the attentional boost effect was eliminated. These data are consistent with the claim that target detection opens an attentional gate that briefly enhances the perceptual processing of coinciding information. This enhancement offsets and masks the negative effects of increased perceptual load. However, if working memory is occupied by another task, post-perceptual processing of the scenes is impaired. Without working memory resources, better perceptual representations do not result in better long-term memory. We conclude that the attentional boost effect can facilitate perceptual processing, but is dependent upon the availability of working memory resources to solidify its effects in long term memory.
Meeting abstract presented at VSS 2013