title: Prefrontal cortex is critical for contextual processing: evidence from brain lesions.
abstract: We investigated the role of prefrontal cortex (PFC) in local contextual processing using a combined event-related potentials and lesion approach. Local context was defined as the occurrence of a short predictive series of visual stimuli occurring before delivery of a target event. Targets were preceded by either randomized sequences of standards or by sequences including a three-stimulus predictive sequence signalling the occurrence of a subsequent target event. PFC lesioned patients were impaired in their ability to use local contextual information. The response time for controls revealed a larger benefit for predictable targets than for random targets relative to PFC patients. PFC patients had reduced amplitude of a context-dependent positivity and failed to generate the expected P3b latency shift between predictive and non-predictive targets. These findings show that PFC patients are unable to utilize predictive local context to guide behaviour, providing evidence for a critical role of PFC in local contextual processing.
authors.affiliation: Helen Wills Neuroscience Institute, University of California Berkeley, 132 Barker Hall, Berkeley, CA 94720-3190, USA. nfogelson@udc.es
authors.forename: Noa
authors.initials: N
authors.lastname: Fogelson
authors.forename: Mona
authors.initials: M
authors.lastname: Shah
authors.forename: Donatella
authors.initials: D
authors.lastname: Scabini
authors.forename: Robert T
authors.initials: RT
authors.lastname: Knight
mesh_terms: D000368:Aged; D004569:Electroencephalography; D018913:Event-Related Potentials, P300 / Q000502:physiology*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008875:Middle Aged; D009483:Neuropsychological Tests; D010775:Photic Stimulation; D017397:Prefrontal Cortex / Q000473:pathology / Q000502:physiology; D011597:Psychomotor Performance / Q000502:physiology*; D020521:Stroke / Q000473:pathology / Q000503:physiopathology; D014796:Visual Perception / Q000502:physiology