Intracranial EEG Correlates of Concurrent Demands on Cognitive Stability and Flexibility

Poster Session A - Saturday, April 13, 2024, 2:30 – 4:30 pm EDT, Sheraton Hall ABC

J. Zhang¹ (jzhang7345@gmail.com), A. Earle-Richardson¹, D. Southwell¹, B. Frauscher¹, T. Egner¹, G.B. Cogan¹; ¹Duke University

Two core capacities of cognitive control are conflict-control, the ability to focus attention on task-relevant stimuli while ignoring distracters (cognitive stability); and task-switching, the ability to shift between different rule-sets to guide behavior (cognitive flexibility). Whether they arise from distinct or overlapping neural mechanisms remains unclear as prior studies investigated these capacities in isolation and used only macroscale neural data (fMRI, scalp EEG). Here, we obtained mesoscale neural data (iEEG) from 8 epilepsy patients while they completed a local/global Navon letter task. The task independently varied demands on conflict-control (congruent vs. incongruent stimuli) and task-switching (repeating vs. switching tasks between trials), allowing us to analyze neural activity associated with congruency, task switching, and their interaction. Patients demonstrated robust behavioral congruency effects and switch costs. Prior work suggests the lateral prefrontal cortex (LPFC) is a primary neural substrate for cognitive stability and flexibility. We examined high-gamma activity within individual LPFC electrodes (N=71), focusing on the electrodes that had significant task-related activity (N=22, 31%). Most of these task-sensitive electrodes were sensitive to at least one effect of interest (N=15, 68%), mostly emerging ~500ms post-stimulus-onset. About half of these effect-sensitive electrodes displayed exclusive effects of congruency or task switching (N=8, 53%), while the others exhibited additive or interactive effects (N=7, 47%). We are currently probing the mechanisms that produce this partial overlap by analyzing adaptation in cognitive stability and flexibility to changing congruent/switch proportions. These results suggest concurrent demands on conflict-control and task-switching have both distinct and overlapping mesoscale neural substrates in LPFC.

Topic Area: EXECUTIVE PROCESSES: Goal maintenance & switching