James Pang, Ph.D.
October 19(Thu) - October 19(Thu), 2023
10am
Online ZOOM (ID: 728-142-6028)
Neuro@noon Seminar
Date: 10am, Thu, Oct 19th
Speaker: James Pang, Ph.D. (Monash University)
Title: Geometric constraints on human brain function
Abstract: The anatomy of the brain necessarily constrains its function, but precisely how remains unclear. For a long time, researchers have thought that it is necessary to map the intricate connectivity of the brain to understand how different areas communicate with each other and thus give rise to patterns of brain activity. In this presentation, I will show that our new approach relying on a simpler model of brain connectivity, which prioritizes the role of the geometric and physical properties of the brain, is sufficient to parsimoniously explain brain dynamics across >10,000 different experimental conditions recorded with human magnetic resonance imaging. Specifically, I will show that cortical and subcortical activity can be understood as resulting from excitations of fundamental, resonance modes of the brain’s geometry (that is, its shape) rather than from modes of complex interregional connectivity, as classically assumed. I will also show that the new approach reveals that brain activations evoked by a cognitive task are not confined to focal areas, as widely believed, but instead excite brain-wide modes with long wavelengths. Finally, I will also show that the close link between geometry and function is explained by a dominant role of wave-like activity, and that wave dynamics can reproduce numerous canonical spatiotemporal properties of spontaneous and evoked recordings. These findings challenge prevailing views and identify a previously underappreciated role of geometry in shaping function, as predicted by a unifying and physically principled model of brain-wide dynamics.