Subspace partitioning in the human prefrontal cortex resolves cognitive interference
Jan Weber, Gabriela Yukari Iwama, Anne‐Kristin Solbakk, Alejandro O. Blenkmann, Pål G. Larsson, Jugoslav Ivanović, Robert T. Knight, Tor Endestad, Randolph F. Helfrich
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.