26 January 1996
Vol 271, Issue 5248

About The Cover

Regions deep within the brain control alertness in humans. The midbrain reticular formation and the intralaminar thalamic nuclei are activated (red and yellow) in normal individuals when they change from a relaxed awake state into a state of high alertness and attention, demonstrating that these structures are active in changing levels of consciousness in the awake state. Lower right: brain structure data from 10 individuals. See 512. [Image: P. E. Roland]