Revisiting the role of persistent neural activity during working memory

Area of Science:

• Neuroscience
• Cognitive Neuroscience
• Systems Neuroscience

Background:

• The dominant theory of working memory (WM) suggests persistent neural activity in the lateral prefrontal cortex (lPFC) underlies information storage.
• Recent research challenges this model, necessitating a re-evaluation of WM's neural underpinnings.

Purpose of the Study:

• To critically review recent findings on the neural mechanisms of working memory.
• To propose a revised model of WM that integrates activity in both the lPFC and sensory cortex.

Main Methods:

• This study is a review of existing literature.
• It synthesizes findings from various experimental studies investigating neural activity during WM tasks.

Main Results:

• High-fidelity representations of WM content are primarily maintained in sensory cortex, not the lPFC.
• The lPFC maintains multiple goal-related variables that modulate sensory cortex activity.
• Working memory involves both persistent activity and temporally dynamic population coding.

Conclusions:

• The traditional model of WM based solely on lPFC persistent activity requires revision.
• A revised model posits a division of labor, with sensory cortex storing information and lPFC guiding attention and biasing sensory processing.
• Understanding the interaction and coordination between lPFC and sensory cortex mechanisms is crucial for a comprehensive view of WM.