Schedule of Events | Symposia

Impact of Task-Engaged PFC-Targeted tDCS on Neural Markers of Proactive Control in Schizophrenia

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

Megan A. Boudewyn¹ (mboudewyn@ucsc.edu), Ana-Maria M. Iosif², Cameron S. Carter³; ¹University of California, Santa Cruz, ²University of California, Davis, ³University of California, Irvine

INTRODUCTION: This study aimed to evaluate the hypothesis that transcranial direct current stimulation (tDCS) targeting the prefrontal cortex (PFC) enhances neural markers of proactive control in individuals with schizophrenia, and that tDCS effects will be maximal under conditions in which participants are performing a task engaging cognitive control neural circuitry, rather than when tDCS is delivered during rest. METHODS: We examined gamma-band power (30-50 Hz) while participants completed the Dot-Pattern Expectancy (DPX) task, after receiving 20 minutes of 2 mA PFC-targeted tDCS, compared to sham. Active or sham stimulation was administered while participants completed the N-back task or while resting in a within-participants design (4 experimental sessions; N=39). RESULTS: We observed a significant three-way interaction of tDCS, task-engagement and DPX trial type (easy versus hard) on gamma-band power (p=0.02). Follow-up analyses decomposing the three-way interaction showed that gamma power was significantly increased at right frontal electrodes following task-engaged PFC-targeted stimulation for difficult trial types (p=0.04). CONCLUSIONS: These findings are consistent with our hypothesis, suggesting that PFC-targeted tDCS can enhance neural correlates of goal maintenance in individuals with schizophrenia. The results also suggest there is value added in administering tDCS during the performance of a task designed to engage the targeted neural circuits (here, the PFC). These results contribute to the growing body of evidence indicating that PFC-tDCS enhances cognitive control processes such as proactive control in individuals with schizophrenia.

Topic Area: EXECUTIVE PROCESSES: Goal maintenance & switching