Department of Psychiatry, University of Wisconsin, Madison, WI, USA
The research goal of this study was to monitor how information is transmitted within the human brain during different states of consciousness.
In this healthy young subject, stimulation of the right premotor cortex leads to electrical activity in widespread areas on the left hemisphere and in associative areas in the back of the head (left). In deep sleep, similar NBS stimulation activates the brain locally but simultaneous EEG shows no spreading of activation (right).
The functioning connections of the human brain are completely different in awake vs. deep sleep states. Future studies in disorders with an altered state of consciousness are warranted.
Courtesy of prof. Giulio Tononi & Marcello Massimini
M Massimini, F. Ferrarelli, R. Huber, SK Esser, H Singh, G Tononi. Breakdown of cortical effective connectivity during sleep. Science, 309: 2228-2231, 2005.
