Unveiling the Abstract Format of Mnemonic Representations

Abstract

Working memory (WM) enables information storage for future use, bridging the gap between perception and behavior. We hypothesize that WM representations are abstractions of low-level perceptual features. Yet the neural nature of these putative abstract representations has thus far remained impenetrable. Here, we demonstrate that distinct visual stimuli (oriented gratings and moving dots) are flexibly re-coded into the same WM format in visual and parietal cortex when that representation is useful for memory-guided behavior. Specifically, the behaviorally relevant features of the stimuli (orientation and direction) were extracted and re-coded into a shared mnemonic format that takes the form of an abstract line-like pattern. We conclude that mnemonic representations are abstractions of percepts that are more efficient than and proximal to the behaviors they guide.

Keywords: working memory, fMRI, representational format