The where and how of attention-based rehearsal in spatial working memory.
Rehearsal in human spatial working memory is accomplished, in part, via covert shifts of spatial selective attention to memorized locations ("attention-based rehearsal"). We addressed two outstanding questions about attention-based rehearsal: the topography of the attention-based rehearsal effect, and the mechanism by which it operates. Using event-related fMRI and a procedure that randomized the presentation of trials with delay epochs that were either filled with a flickering checkerboard or unfilled, we localized the effect to extrastriate areas 18 and 19, and confirmed its absence in striate cortex. Delay-epoch activity in these extrastriate regions, as well as in superior parietal lobule and intraparietal sulcus, was also lateralized on unfilled trials, suggesting that attention-based rehearsal produces a baseline shift in areas representing the to-be-remembered location in space. No frontal regions (including frontal eye fields) demonstrated lateralized activity consistent with a role in attention-based rehearsal.
Postle
B R
BR
Department of Psychology, University of Wisconsin-Madison, WI 53706, USA. postle@wisc.edu
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Jonides
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Smith
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D'Esposito
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D000293:Adolescent; D000328:Adult; D001288:Attention / Q000502:physiology*; D005074:Evoked Potentials, Visual / Q000502:physiology; D006801:Humans; D008279:Magnetic Resonance Imaging; D008570:Memory, Short-Term / Q000502:physiology*; D010775:Photic Stimulation; D013028:Space Perception / Q000502:physiology*