Neural modeling of frontal evoked responses predicts transient beta events influence inhibitory control via slow GABAergic inhibition

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

Darcy Diesburg¹ (darcy_diesburg@brown.edu), C. J. Abeshaus², Stephanie Jones¹; ¹Brown University, ²Scripps College

In the Stop-Signal Task, frontocentral (FC) EEG signatures such as event-related potentials (ERPs) and pre-stop transient beta (15-29Hz) events (BEs) are often considered proxies of inhibitory control processes. However, minimal understanding of the neural circuit-mechanisms that create these signals makes it challenging to integrate them within behavioral-cognitive theories of stopping. Recent work with Human Neocortical Neurosolver’s (HNN) biophysical model of the thalamocortical cell- and circuit-mechanisms producing human M/EEG signals predicted mechanisms of stop-signal-locked FC-ERPs (Diesburg et al., 2024). Changes in timing and strength of thalamocortical inputs produced differences in timing and amplitudes of FC-ERP deflections in successful (SS) versus failed stops (FS). A larger P2 deflection in FS emerged from stronger early pyramidal cell spiking, possibly associated with erroneous responding. While insightful, these simulations did not account for influences of pre-stop BEs, known to be more numerous during SS and predicted to influence ERPs and underlying cell spiking via recruitment of GABAb-ergic currents (Law et al., 2022). Here, we tested whether BE-generating mechanisms induce differences in SS versus FS FC-ERP amplitudes and modeled spiking activity related to behavior. Simulating pre-stop BEs that recruit GABAb currents, we found that BEs in the 300ms preceding the first thalamocortical input in SS simulations reduced the amplitude of the P2, analogous with the data. Further, pyramidal cell spiking was reduced, supporting the notion that a decrease in early spiking supports SS. These results suggest that the mechanisms that generate BEs drive condition differences in FC-ERPs and downregulate early spiking to support inhibitory control.

Topic Area: EXECUTIVE PROCESSES: Monitoring & inhibitory control