Theme keynote lecture

General anesthesia is a drug-induced, reversible condition comprised of five behavioral states: hypnosis (loss of consciousness), amnesia (loss of memory), analgesia (loss of pain sensation), akinesia (immobility), and hemodynamic stability with control of the stress response. The mechanisms by which anesthetic drugs induce the state of general anesthesia remain one of the biggest mysteries of modern medicine. We have been using three experimental paradigms to study general anesthesia-induced loss of consciousness in humans: combined fMRI/EEG recordings, highdensity EEG recordings and intracranial recordings. These studies are allowing us to establish precise neurophysiological, neuroanatomical and behavioral correlates of general anesthesia. We will discuss the relation between our findings and two other important altered states of arousal: sleep and coma. Our findings suggest that the state of general anesthesia is not as mysterious as currently believed.