Human prefrontal lesions increase distractibility to irrelevant sensory inputs.
Neurological patients with focal lesions in either the dorsolateral prefrontal cortex, temporal-parietal junction or the posterior hippocampus, and control subjects, were tested on a task requiring short-term retention of environmental sounds. Subjects had to indicate whether initial and subsequent test sounds were identical in two conditions. The initial and test sounds were separated by either a silent period varying from 4 to 12.6 s (no-distractor condition) or a series of irrelevant tones (distractor condition). Prefrontal patients were significantly impaired by distractors at all delays, hippocampal patients were impaired only at longer delays, while temporal-parietal patients performed similar to controls. The findings suggest that dorsolateral prefrontal cortex is crucial for gating of distracting information during delay tasks.
Department of Neurology, U.C. Davis, Martinez, USA.
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Chao
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Knight
D000368:Aged; D001931:Brain Mapping; D002561:Cerebrovascular Disorders / Q000473:pathology*; D005260:Female; D006624:Hippocampus / Q000473:pathology*; D006801:Humans; D008297:Male; D008570:Memory, Short-Term; D008875:Middle Aged; D009475:Neurons, Afferent; D017397:Prefrontal Cortex / Q000473:pathology*; D013647:Task Performance and Analysis; D013997:Time Factors