Retrospective and prospective prioritization in visual working memory

A growing body of research indicates that items assigned with a higher ‘value’ prior to presentationare better recalled in working memory tasks. This has been interpreted as reflecting the strategic prioritization of these items via selective attention during encoding, maintenance, and retrieval. The current study sought to establish whether value-based prioritization effects can be obtained in a sequential visual working memory task when value information is provided retrospectively during maintenance and items are no longer present in the environment. Enhanced recall of high value items along with costs to low value items (relative to equal value trials) was observed, although the high value benefit was only reliably found on the final sequence position. In comparison, a follow- up experiment in which values were provided prior to presentation found large prioritization benefits across sequence positions. This study illustrates that attention can be retrospective shifted between working memory representations based on value, but the effectiveness of this strategic process depends on item availability and accessibility, either in the environment or in working memory.