Schedule of Events | Symposia

The Role of Human Subthalamic Nucleus in Inhibition of Competing Task Representations

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

Nathan Cremers¹ (nathan-cremers@uiowa.edu), Nathan Chalkley¹, Benjamin Rangel², Jan Wessel¹; ¹University of Iowa, ²Brown University

Inhibitory control is crucial for flexible, intelligent behavior. Evidence suggests that the subthalamic nucleus (STN) plays a critical role in domain-general inhibition of both actions and cognition. In this study, we examine the domain-general role of STN by testing its role in inhibiting task representations. We leverage data from Parkinson’s Disease patients with deep brain stimulators (DBS) implanted in the STN. STN-DBS disrupts normal STN activity, allowing us to assess its causal role by comparing performance during DBS-on and DBS-off conditions. To test inhibition of task representations, we utilize a task that prompts the reactivation of conflicting representations. The necessary inhibition of the conflicting representation incurs a reaction time cost which serves a behavioral marker of representational conflict. So far, 16 STN-DBS patients have performed two sessions of this task – one with DBS-on and one with DBS-off – while undergoing EEG recording. We used representational similarity analysis (RSA) of scalp-wide EEG to measure the strength of the correct and conflicting task representations. We predicted that reaction time costs and strength of the conflicting representation would be greater with DBS-on, due to the disruption of the STN. However, behavioral results show no group-level differences in reaction time or accuracy between DBS sessions. Conversely, RSA shows that conflicting task representation are suppressed with DBS-off. Finally, using mixed effect modelling, we show that stronger conflicting representations predict slower reaction times specific to the DBS-on session. While preliminary, these results suggest that the STN may be active in the inhibition of task representations.

Topic Area: EXECUTIVE PROCESSES: Monitoring & inhibitory control