BME PhD Prospectus Defense: Omar El Sayed

Title: "Neural Control of Behavior: Circuit Mechanisms, Inter-regional Communication, and Sensorimotor Computation"

Advisory Committee: Michael Economo, PhD – BME (Co-Advisor) Brian DePasquale, PhD – BME (Co-Advisor) Matthias Stangl, PhD – BME (Chair) Chandramouli Chandrasekaran, PhD – Anatomy & Neurobiology, Psychological and Brain Sciences

Abstract: The brain controls behavior through a highly distributed and hierarchical network of interconnected regions, yet understanding how flexible, goal-directed behavior emerges from the coordinated activity of this network remains a central challenge in neuroscience. This is particularly acute in sensorimotor circuits, where higher-order regions plan and coordinate movements through descending control of lower-level areas, while sensory feedback is continuously integrated across the hierarchy to update and refine motor output. The central goal of this proposal is to determine how information is routed and transformed across this distributed system to support sensorimotor computation and enable flexible, goal-directed behavior. Aim 1 will investigate the role of distinct cortical descending pathways in shaping subcortical dynamics during motor planning and execution. Aim 2 will develop BiXformer, a novel transformer-based model to disentangle dynamic and directed information flow across neural populations. Finally, Aim 3 will infer the structure of sensorimotor computations across the motor hierarchy. Together, these aims will establish a mechanistic and computational foundation for understanding how hierarchical circuits coordinate sensation and action, with broad implications for understanding how disruptions to these circuits give rise to neurological and psychiatric disorders.