Gabriela Iwama

Subspace partitioning in the human prefrontal cortex resolves cognitive interference

Abstract:

The human prefrontal cortex (PFC) constitutes the structural basis underlying flexible cognitive control, where mixed-selective neural populations encode multiple task features to guide subsequent behavior. The mechanisms by which the brain simultaneously encodes multiple task–relevant variables while minimizing interference from task-irrelevant features remain unknown. Leveraging intracranial recordings from the human PFC, we first demonstrate that competition between coexisting representations of past and present task variables incurs a behavioral switch cost. Our results reveal that this interference between past and present states in the PFC is resolved through coding partitioning into distinct low-dimensional neural states; thereby strongly attenuating behavioral switch costs. In sum, these findings uncover a fundamental coding mechanism that constitutes a central building block of flexible cognitive control.

Authors:

  • Jan Weber

  • Gabriela Iwama

  • Anne-Kristin Solbakk

  • Alejandro O. Blenkmann

  • Pal G. Larsson

  • Jugoslav Ivanovic

  • Robert T. Knight

  • Tor Endestad

  • Randolph Helfrich

Date: 2023

DOI: https://doi.org/10.1073/pnas.2220523120

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