Common and distinct neural correlates of perceptual and memorial selection
A working memory selection task combining directed-forgetting and memory-scanning paradigms was used to test the hypothesis that difficulty in selecting target from distractor items in working memory depends on the competition between target and distractor representations, as is commonly assumed in perceptual selection research. Participants memorized two trigrams and were then cued to select one as the new memory set and forget the other. They later saw a test letter and made judgment as to whether the letter was in the selected trigram, i.e., the new memory set. Selection difficulty was examined by manipulating the type of selection cues and the time the cue could be utilized. While re-presenting the targets in the cue display facilitated selection, re-presenting distractors did not impede selection. The results suggest that working memory selection may depend more on the activation from representations of the target than of the distractor.