DARPA Meeting on Continuous Assisted Performance
Las Vegas, August 21-23, 2001.
Cognitive Brain Dynamics
S. Makeig
The Salk Institute
10010 North Torrey Pines Rd.
La Jolla, CA 92107, USAUntil very recently, the focus of most research on brain dynamics was on bottom-up or feedforward processing of stimulus information. Very recent electrophysiologal evidence, however, from depth electrodes in animals and humans shows that the brain's response to informative events involves coherent brain dynamic events that transiently link oscillatory field potentials occuring in separate cortical and subcortical brain areas. These events occur in a wide range of frequencies (0 to 60 Hz and above) within wide and narrow frequency bands. Time/frequency analysis suggests some of these events begin in the frontal lobe and appear to organize the brain's top-down response to new information and changing circumstances. Thus, they are prime candidates for understanding and monitoring important changes in cognitive capabilities that may occur with fatigue and sleep deprivation. We have developed techniques for combining information theory and time/frequency analysis to build spatiotemporal models of these events recorded non-invasively through high-density EEG. The potential for breakthroughs in understanding brain cognition during sleep deprivation appears high. Potential applications of this technology include sensitive real-time cognitive status monitoring and biofeedback.