ROLE OF DORSOLATERAL-PREFRONTAL CORTEX AND FRONTAL EYE FIELDS IN MAINTAINING WORKING MEMORY IN THE PRESENCE OF A DISTRACTOR

Abstract

The prefrontal cortex maintains working memory information in the presence of distracting stimuli. It has long been thought that sustained activity in individual neurons or groups of neurons was responsible for the maintenance of information in the form of a persistent, stable code. Here, we show that upon the presentation of a distractor, information in dorsolateral-prefrontal cortex (dlPFC) is reorganized into a different pattern of activity to create a morphed stable code without losing information. In contrast, the code in the frontal eye fields (FEF) persisted across different delay periods, but exhibited significant instability and information loss after the presentation of a distractor. We found that neurons with nonlinear mixed-selective responses were necessary and sufficient for the morphing of code, and these neurons were found to be more abundant in the dlPFC than the FEF. This suggests that mixed selectivity provides populations with code-morphing capability, a property that may underlie cognitive flexibility.