Abstract
Attention samples spatial positions, visual objects or auditory streams rhythmically. This has been reported for tasks where the attended information was perceptually present. Here we tested whether attentional sampling also applies to internal representations held in working memory. Participants memorized four spatial positions that formed the endpoints of two objects, one of which was cued for a delayed match-non-match test. When uncued positions were probed, participants responded faster to those located on the same object as the cued position than to those located on the other object, revealing object-based attention in working memory. Manipulating the interval between cue and probe revealed that object-based attention oscillated at 6 Hz. Moreover, oscillations showed an antiphase relationship between objects, suggesting that attention sampled them in alternation. The striking similarity between rhythmic sampling of mental representations and perceptual information suggests that attentional sampling is a general mechanism of information processing in human cognition.