“Unraveling Large-scale Brain Dynamics Underlying Perceptual Awareness”

Biyu Jade He, Ph.D. 
National Institute of Neurological Disorders and Stroke
National Institute of Health

The human brain is a large-scale, nonlinear dynamical system. The main focus of my laboratory at the NIH is to study how large-scale brain dynamics relate to human cognition – in particular, perceptual awareness – while taking into account perspectives gained from studying spontaneous brain activity and nonlinear brain dynamics. For instance, our recent findings using fMRI and ECoG in humans suggest that the effect of a sensory stimulus or task demand is not to evoke a stereotypical response that adds linearly onto the constantly changing ongoing activity. By contrast, in line with nonlinear dynamical systems view, incoming sensory stimuli strongly interact with ongoing cortical dynamics to actively shape the evolving cortical activity trajectory. In this talk, I will discuss our recent studies using multimodal imaging (fMRI/EEG/MEG) and brain stimulation in humans, combined with computational approaches, to study the neural bases of perceptual awareness and movement intention. These studies illustrate the importance of understanding the roles of spontaneous activity, nonlinear dynamics, and top-down predictions in shaping perception and action.