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)

Stressful life situations can impair or facilitate various cognitive functions. In the present study, the effect of examination stress on students was examined using two executive function tasks, task-switching and the Stroop task, in a between-subject crossover design. Students showed increased anxiety in the 2 week period prior to exams compared to the beginning of the semester, manifested as higher scores on the Spielberger State-Trait Anxiety Scale and a shift to more sympathetic activation when heart rate variability was assessed. During (...) the stressful period, the switching cost was reduced on a spatial task-switching paradigm and reaction times in the Stroop task were faster. This is the first study to show stress-induced facilitation of performance on these executive function tasks. (shrink)