Prefrontal cortex regulates inhibition and excitation in distributed neural networks
Journal/Book: Acta Psychol. 1999; 101: PO Box 211, 1000 AE Amsterdam, Netherlands. Elsevier Science Bv. 159-178.
Abstract: Prefrontal cortex provides both inhibitory and excitatory input to distributed neural circuits required to support performance in diverse tasks. Neurological patients with prefrontal damage are impaired in their ability to inhibit task-irrelevant information during behavioral tasks requiring performance over a delay. The observed enhancements of primary auditory and somatosensory cortical responses to task-irrelevant distracters suggest that prefrontal damage disrupts inhibitory modulation of inputs to primary sensory cortex, perhaps through abnormalities in a prefrontal-thalamic sensory gating system. Failure to suppress irrelevant sensory information results in increased neural noise, contributing to the deficits in decision making routinely observed in these patients. In addition to a critical role in inhibitory control of sensory flow to primary cortical regions, and tertiary prefrontal cortex also exerts excitatory input to activity in multiple sub-regions of secondary association cortex. Unilateral prefrontal damage results in multi-modal decreases in neural activity in posterior association cortex in the hemisphere ipsilateral to damage. This excitatory modulation is necessary to sustain neural activity during working memory. Thus, prefrontal cortex is able to sculpt behavior through parallel inhibitory and excitatory regulation of neural activity in distributed neural networks. PsycINFO classifications: 2346; 2520; 2530; 2540; 3213; 3297.
Note: Review Knight RT, Univ Calif Berkeley, Dept Psychol, 3210 Tolman Hall, Berkeley,CA 94720 USA
Keyword(s): prefrontal; inhibition; excitation; attention; schizophrenia; EVENT-RELATED POTENTIALS; FRONTAL-LOBE LESIONS; CEREBRAL BLOOD-FLOW; SOMATOSENSORY EVOKED-POTENTIALS; AUDITORY SELECTIVE ATTENTION; WORKING-MEMORY TASKS; CYTOARCHITECTONIC DEFINITION; VENTROPOSTERIOR THALAMUS; AFFERENT TRANSMISSION; BRAIN POTENTIALS