HUMAN PREFRONTAL LESIONS INCREASE DISTRACTIBILITY TO IRRELEVANT SENSORY INPUTS

NEUROLOGICAL patients with focal lesions in either the dorsolateral pr efrontal cortex, temporal-parietal junction or the posterior hippocamp us, and control subjects, were tested on a task requiring short-term r etention of environmental sounds. Subjects had to indicate whether ini tial and subsequent test sounds were identical in two conditions. The initial and test sounds were separated by either either a silent perio d varying from 4 to 12.69 (no-distractor condition) or a series of irr elevant tones (distracter condition). Prefrontal patients were signifi cantly impaired by distracters at all delays, hippocampal patients wer e impaired only at longer delays, while temporal-parietal patients per formed similar to controls. The findings suggest that dorsolateral pre frontal cortex is crucial for gating of distracting information during delay tasks.