title: A Neurophysiological Study of Semantic Processing in Parkinson's Disease.
abstract: Cognitive-linguistic impairments in Parkinson's disease (PD) have been well documented; however, few studies have explored the neurophysiological underpinnings of semantic deficits in PD. This study investigated semantic function in PD using event-related potentials.
  
  
  
  Eighteen people with PD and 18 healthy controls performed a semantic judgement task on written word pairs that were either congruent or incongruent.
  
  
  
  The mean amplitude of the N400 for new incongruent word pairs was similar for both groups, however the onset latency was delayed in the PD group. Further analysis of the data revealed that both groups demonstrated attenuation of the N400 for repeated incongruent trials, as well as attenuation of the P600 component for repeated congruent trials.
  
  
  
  The presence of N400 congruity and N400 repetition effects in the PD group suggests that semantic processing is generally intact, but with a slower time course as evidenced by the delayed N400. Additional research will be required to determine whether N400 and P600 repetition effects are sensitive to further cognitive decline in PD. (JINS, 2017, 23, 78-89).
authors.affiliation: 1University of Queensland,School of Health and Rehabilitation Sciences,Brisbane,Australia.
authors.forename: Anthony J
authors.initials: AJ
authors.lastname: Angwin
authors.affiliation: 2University of Queensland,UQ Centre for Clinical Research,Brisbane,Australia.
authors.forename: Nadeeka N W
authors.initials: NN
authors.lastname: Dissanayaka
authors.affiliation: 1University of Queensland,School of Health and Rehabilitation Sciences,Brisbane,Australia.
authors.forename: Alison
authors.initials: A
authors.lastname: Moorcroft
authors.affiliation: 4University of Queensland,Centre for Advanced Imaging,Brisbane,Australia.
authors.forename: Katie L
authors.initials: KL
authors.lastname: McMahon
authors.affiliation: 2University of Queensland,UQ Centre for Clinical Research,Brisbane,Australia.
authors.forename: Peter A
authors.initials: PA
authors.lastname: Silburn
authors.affiliation: 1University of Queensland,School of Health and Rehabilitation Sciences,Brisbane,Australia.
authors.forename: David A
authors.initials: DA
authors.lastname: Copland
mesh_terms: D000368:Aged; D003072:Cognition Disorders / Q000175:diagnosis* / Q000209:etiology*; D004569:Electroencephalography; D005071:Evoked Potentials / Q000502:physiology; D005260:Female; D006801:Humans; D007600:Judgment; D007806:Language Disorders / Q000209:etiology*; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D010300:Parkinson Disease / Q000150:complications* / Q000523:psychology*; D011930:Reaction Time / Q000502:physiology; D012660:Semantics; D013997:Time Factors; D014705:Verbal Behavior / Q000502:physiology; D014825:Vocabulary
keywords: Event-related potentials; N400; P600; Parkinson’s disease; Semantics; memory