title: The pattern of attentional deficits in Parkinson's disease.
abstract: BACKGROUND
  Cognitive impairment without dementia is frequent in Parkinson's disease. It often presents as a dysexecutive syndrome with deficient attentional resource allocation. The nature of attention deficits in Parkinson's disease has rarely been investigated with robust, theory-based tasks. The main objective of the present study was to investigate attention disorders in Parkinson's disease patients by applying a paradigm based on a model of attention. We also sought to identify the main demographic and clinical characteristics associated with attention deficits in Parkinson's disease.
  
  
  METHODS
  Eighty non-demented Parkinson's disease patients and 60 healthy controls participated in the study. Attention was assessed in a computer-controlled reaction time paradigm. The test session comprised a simple reaction time task and four choice reaction time tasks: a go/no-go task, a one-dimension, focused-attention task, a two-dimension, divided-attention task and an alternating task. Performance was assessed by composite measures: (i) cognitive reaction time, corresponding to the difference between the simple reaction time and the choice reaction time in the given condition, and (ii) reaction time variability, corresponding to the sum of the coefficients of variance of the reaction times. Accuracy was also considered.
  
  
  RESULTS
  Apart from an overall slowing and greater reaction time variability, Parkinson's disease patients were only significantly impaired in the alternating condition. This set-shifting impairment was associated with their performance in the go/no-go and divided-attention conditions.
  
  
  CONCLUSIONS
  Our systematic assessment of the different attentional subcomponents revealed that mental flexibility is particularly impaired in non-demented Parkinson's disease patients.
authors.affiliation: Laboratoire de Neurosciences Fonctionnelles et Pathologies, EA 4559, University of Lille 2, Lille, France. kathy.dujardin@univ-lille2.fr
authors.forename: Kathy
authors.initials: K
authors.lastname: Dujardin
authors.forename: Céline
authors.initials: C
authors.lastname: Tard
authors.forename: Alain
authors.initials: A
authors.lastname: Duhamel
authors.forename: Arnaud
authors.initials: A
authors.lastname: Delval
authors.forename: Caroline
authors.initials: C
authors.lastname: Moreau
authors.forename: David
authors.initials: D
authors.lastname: Devos
authors.forename: Luc
authors.initials: L
authors.lastname: Defebvre
mesh_terms: D001288:Attention / Q000502:physiology*; D003072:Cognition Disorders / Q000209:etiology* / Q000503:physiopathology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010300:Parkinson Disease / Q000150:complications* / Q000503:physiopathology; D011930:Reaction Time