Schedule of Events | Symposia

The functional organization of task-tailored neural representations for control in human neocortex

Poster Session A - Saturday, March 29, 2025, 3:00 – 5:00 pm EDT, Back Bay Ballroom/Republic Ballroom

Haley Keglovits¹, Robert Zielinski¹, Apoorva Bhandari¹, David Badre¹; ¹Brown University

Cognitive control underlies the adaptability of human behavior. The lateral prefrontal cortex (lPFC) is widely associated with cognitive control function and is thought to represent diverse task information flexibly for use as a top-down control signal. In our prior work (Bhandari et al., 2024), we found that control representations in lPFC are organized in a task tailored way to permit robust, efficient readout. For example, when the task required following a hierarchical rule – wherein a context stimulus feature conditioned which other stimulus feature was relevant to a response – the task representation was organized along an abstract context axis. Further, subspaces for each subtask compressed irrelevant inputs for that subtask and were rotated in order to minimize interference. However, this study left open how specialized such geometry is within lPFC and which of these characteristics are also found in broader cortical networks. To investigate, we measured neural responses while humans performed two categorization tasks: one with a flat, conjunctive rule structure and one with a hierarchical, context-dependent rule structure. Whole brain representational similarity analyses found widespread context sensitivity in the hierarchical task, such that stimulus features were differentially encoded based on context relevance, including in unimodal sensory cortex. This indicates that neural representation is shaped by task context broadly in the brain. Further, we employed dimensionality reduction techniques on patterns of neural activity to explore common organizing principles in task geometry. Our results provide a novel window into brain function and organization based on geometric features of task representations.

Topic Area: EXECUTIVE PROCESSES: Goal maintenance & switching