When people return to consciousness after receiving anesthesia, a more primitive area of their brains--the brainstem--becomes active first, followed by the thalamus, the hypothalamus, and the anterior cingulate cortex in the frontal lobe, a study reported April 4 in The Journal of Neuroscience has found. These brain structures thus appear to form a foundation for the conscious state, the scientists believe. The same structures also activate upon awakening from natural stage-two sleep. Other researchers have found that restored activity in the anterior cingulate cortex correlates with the level of responsiveness in brain-injured patients.
More information about the brain function of traumatic brain-injured patients can be found in Psychiatric Newshere. More information about traumatic brain injury in general can be found in the American Psychiatric Publishing Textbook of Traumatic Brain Injury,Second Edition.