Thalamic modulation of competition between large-scale brain networks revealed by intracranial EEG

Poster Session F - Tuesday, April 16, 2024, 8:00 – 10:00 am EDT, Sheraton Hall ABC

Emily Davidson¹ (emily.davidson@mail.mcgill.ca), Zoe Lusk², Dian Lyu², Josef Parvizi², Nathan Spreng¹; ¹McGill University, ²Stanford University

This project examines the effect of changes in thalamic activation on the activity within canonical, cortical resting-state networks (RSNs), emphasizing the three networks commonly found to be antagonistic to each other: the default network (DN), salience network (SN) and dorsal attention network (DAN). Three subjects were examined with intracranial-EEG (iEEG) while watching two distinct, animated movies. Electrode placement varied across subjects but in all cases included thalamic regions as well as channels corresponding to each of the seven canonical resting-state networks (Yeo 2011). Data was preprocessed and analyzed using the MNE-Python toolbox. Channels were filtered for power line noise and a high-pass filter of 0.1 Hz was applied. Channels were broken up into 1 second epochs. Events were recorded in which channels associated with the DN and SN were anticorrelated over the course of 1 second intervals. Each epoch corresponding to such an anticorrelation event was analyzed using directed phase-locking interval (dPLI) to determine which channels showed a significant leading and lagging relationship in temporal phase within the alpha (8-12 Hz) broadband range. Results demonstrated during epochs where the default and salience networks were anticorrelated, thalamic activation significantly lagged the SN, and the DN lagged the thalamus and SN. The DAN showed no significant leading or lagging relationships with the thalamus, DN, or SN within these events. This work offers insight into the way the thalamus may play a role in modulating the relationships between RSNs.

Topic Area: OTHER