The ability to image the human brain has provided a new perspective for neuropsychologists in their efforts to understand, diagnose, and treat insults to the human brain that might occur as the result of stroke, tumor, traumatic injury, degenerative disease, or errors in development. These new ®ndings are the major theme of this special issue. In our article, we consider brain networks that carry out the functions of attention. We outline several such networks that have been studied in normal and (...) pathological states. These include networks for orienting to sensory stimuli, for maintaining the alert state, and for orchestrating volitional control. (shrink)