Laura Lewis, Ph.D.*
Junior Fellow, Society of Fellows
Harvard University

Fast Multimodal Neuroimaging for Tracking Whole-brain Dynamics in Sleep and Wake

Abstract:

            Human cognition and behavior varies dramatically over the course of the day, as the brain transitions between alert, drowsy, and sleep states. Healthy brain function depends on this ability to flexibly reorganize large-scale brain networks over time, but studies of whole-brain network dynamics have been severely limited by the low spatiotemporal resolution of current noninvasive neuroimaging methods. We developed a multimodal approach integrating fast functional magnetic resonance imaging (fMRI) and simultaneous electroencephalography (EEG) to enable the direct imaging of neural oscillations in the human brain. Using this approach, we demonstrated that fMRI can detect faster brain activity than previously thought, achieving timescales of hundreds of milliseconds. We then applied this technique to study human brain activity across sleep and wake states, and show it can identify novel thalamic and cortical circuit activity that predicts transitions into and out of sleep. These studies develop a framework for tracking whole-brain dynamics in humans, and demonstrate their potential for identifying the neural mechanisms that rapidly and flexibly control brain states and cognition, with broad future applications in clinical and basic neuroscience.

Host: Shella Keilholz