Fast multimodal imaging of brain dynamics underlying sleep and wakefulness


Laura D. Lewis
Boston University


Polina Golland
When we fall asleep, brain function and physiology are transformed,
and this process is essential for neurological health. Understanding
the neural basis of sleep requires imaging methods that can capture
multiple aspects of brain physiology at fast timescales. We develop
approaches for analyzing human brain physiology using multimodal
neuroimaging, and apply them to investigate the neural origins and
consequences of sleep. We found that accelerated methods for fMRI can
enable imaging subsecond neural dynamics throughout the human
brain. We applied these methods to investigate the neural dynamics
that occur at state transitions, and identified temporal dynamics
within thalamocortical networks that precede the moment of awakening
from sleep. In addition, we developed a method to image cerebrospinal
fluid flow, and discovered large waves of fluid flow that appear in
the sleeping human brain. Together, these studies highlight the new
biological information that can be extracted from fast fMRI data, and
use this approach to discover neurophysiological dynamics unique to
the sleeping brain.