Prioritization of semantic over visuo-perceptual aspects in multi-item working memory

Abstract

Working Memory (WM) keeps information temporarily available for upcoming tasks. How the contents of WM are distinguished from perceptual representations on the one hand, and from long-term memories on the other, is still debated. Here, we leveraged recent evidence for a reversal of processing dynamics when retrieving episodic long-term memories as opposed to perceiving visual input. In two experiments (n=75 and n=103), we asked participants to hold one or more items in WM and to report their low-level perceptual and high-level semantic qualities. In both experiments, we found faster responses to the items semantic qualities, indicating prioritization over visuo-perceptual aspects, when two or more items were held concurrently in WM. These dynamics of accessing information in multi-item WM were akin to those in retrieving episodic long-term memories and opposite to those in processing visual inputs. Little to no semantic prioritization was evident during single-item maintenance, consistent with a strictly capacity-limited focus of attention within which WM information can be transformed into a prospective action plan.