Does spatial attention modulate sensory memory?

Abstract

According to some theoretical models, information contained in visual short-term memory (VSTM) consists of two main memory stages/storages: sensory memory, a system wherein information is stored for a brief time with high detail and low resistance to visual interference, and visual working memory, a low-capacity system wherein information is protected from visual interference and maintained for longer delays. Previous studies have consistently shown a strong relationship between attention and visual working memory. However, evidence is contradictory on whether or not attention modulates the construction and maintenance of visual representations in sensory memory. Here, we examined whether and how spatial attention differentially affects sensory and working memory contents, by separately analysing attentional costs and attentional benefits. Results showed that both sensory memory and visual working memory were reliably affected by the distribution of spatial attention, suggesting that spatial attention modulates the VSTM content starting from very early stages of memory storage. Moreover, endogenously attending a specific location led to similar performance in sensory and working memory, and therefore to larger attentional benefits in working memory (where there was more room for improvement than in sensory memory, because of worse performance in unattended locations). On the other hand, exogenous attentional capture by peripheral unpredictive cues produced invariant attentional costs and invariant attentional benefits regardless of the memory type, with performance being higher in sensory memory than in working memory even at the attended location.