Revisiting the role of persistent neural activity during working memory.
What are the neural mechanisms underlying working memory (WM)? One influential theory posits that neurons in the lateral prefrontal cortex (lPFC) store WM information via persistent activity. In this review, we critically evaluate recent findings that together indicate that this model of WM needs revision. We argue that sensory cortex, not the lPFC, maintains high-fidelity representations of WM content. By contrast, the lPFC simultaneously maintains representations of multiple goal-related variables that serve to bias stimulus-specific activity in sensory regions. This work highlights multiple neural mechanisms supporting WM, including temporally dynamic population coding in addition to persistent activity. These new insights focus the question on understanding how the mechanisms that underlie WM are related, interact, and are coordinated in the lPFC and sensory cortex.
Division of Science and Mathematics, New York University Abu Dhabi, 19 Washington Square North, New York, NY 10011, USA. Electronic address: kartik.sreenivasan@nyu.edu.
Kartik K
KK
Sreenivasan
Department of Psychology, and Center for Neural Science, New York University, 6 Washington Place, New York, NY 10003, USA.
Clayton E
CE
Curtis
Helen Wills Neuroscience Institute, and Department of Psychology, University of California, Berkeley, 132 Barker Hall, Berkeley, CA 94720, USA.
Mark
M
D'Esposito
D000818:Animals; D002540:Cerebral Cortex / Q000502:physiology*; D006801:Humans; D008570:Memory, Short-Term / Q000502:physiology*; D009474:Neurons / Q000502:physiology*; D017397:Prefrontal Cortex / Q000502:physiology*
MVPA; decoding; fMRI; forward encoding; prefrontal cortex; top down; working memory