Attention modulates retrieval performance and maintenance of representations in visual working memory

"We live in an age of information overload. To optimize our daily task performance, we need to adopt and discard information critically. However, the mechanisms of focusing on task-relevant information and ignoring irrelevant information, and in which states the relevant and irrelevant information are maintained in mind, are largely unknown. The current work investigated how multiple memory objects are retained and manipulated by objects' task relevances and selective attention. In a mixed-design working memory (WM) study, the reliability of a spatial cue that predicted the recall of one of two memory colors was manipulated in three conditions (i.e., nonpredictive: 50% reliable; predictive: 75% reliable; deterministic: 100% reliable) as within-subject factor, and selective attention was directed externally by a pre-cue and internally by a retro-cue as between-subject factor. Depending on the cue reliability, participants memorized one or both of two distinct memory colors. They conducted a series of visual searches concurrently during the WM delay, followed by a test in which participants had to recall one of the memory colors. We used the memory-based attentional capture effect for intervening visual searches during the delay as a behavioral proxy to represent the strength of memory representations. Therefore, our experimental design allowed us to examine the attentional effects on both WM retrieval performance and internal memory representations.The results of the present experiments suggested that guiding attention externally could better improve memory retrieval performance than guiding attention internally and manipulating information priority through cue reliability could also influence memory performance, but not in a linear manner. Importantly, external/internal attention and task relevance could modulate memory representations, both quantitatively (in the degree of memory representation strength) and qualitatively (all-or-none). However, their modulation effects were not as strong as that on the retrieval performance, suggesting a dissociation (partially or wholly) between our measures of memory representation strength and final retrieval performance. We also investigated the temporal changes of strength of memory representations during the WM delay and provided partial support to the claim that guided attention protects memory representations from degradation or volatility.This study, to our knowledge, is the first to systematically investigate the effects of cue type and reliability on WM performance at the retrieval and memory representations during the maintenance. We also demonstrated the potential of using memory-based attentional capture effect to represent memory representations. Future researchers may want to use this paradigm in more research scenarios."--Pages ii-iii.