title: Children with unilateral cerebral palsy show diminished implicit motor imagery with the affected hand.
abstract: OBJECTIVE
  Motor imagery refers to the mental simulation of a motor action without producing an overt movement. Implicit motor imagery can be regarded as a first-person kinesthetic perceptual judgement, and addresses the capacity to engage into the manipulation of one's body schema. In this study, we examined whether children with unilateral cerebral palsy (CP) are able to engage in implicit motor imagery.
  
  
  METHODS
  A modified version of the hand laterality judgment task was employed. Erroneous responses, reaction times, and event-related potentials from the electroencephalograph were analysed.
  
  
  RESULTS
  In 13 children with typical development (mean age 10y 7mo, SD 1y 2mo; seven male, six female), we observed the classic rotation direction effect. Specifically, when comparing outward rotated with inward rotated hand pictures, decreased accuracy and increased response times were observed. Event-related potentials analyses of the electroencephalogram revealed a more marked N1 and an enhanced rotation-related negativity.
  
  
  CONCLUSIONS
  These findings suggest that an implicit motor imagery strategy was used to solve the task. However, in 10 children with unilateral CP (mean age 10y 7mo, SD 2y 5mo; five male, five female), these effects were observed only when the less-affected hand was involved. This observation suggests that children with CP could benefit from visual training strategies.
authors.affiliation: Behavioural Science Institute, Radboud University Nijmegen, Nijmegen, the Netherlands.
authors.forename: Marijtje L A
authors.initials: ML
authors.lastname: Jongsma
authors.affiliation: Behavioural Science Institute, Radboud University Nijmegen, Nijmegen, the Netherlands.
authors.forename: C Marjolein
authors.initials: CM
authors.lastname: Baas
authors.affiliation: Behavioural Science Institute, Radboud University Nijmegen, Nijmegen, the Netherlands.
authors.forename: Anouk F M
authors.initials: AF
authors.lastname: Sangen
authors.affiliation: Department of Pediatric Rehabilitation, Sint Maartenskliniek, Nijmegen, the Netherlands.
authors.forename: Pauline B M
authors.initials: PB
authors.lastname: Aarts
authors.affiliation: Cognitive Psychology and Ergonomics, University of Twente, Enschede, the Netherlands.|Department of Cognitive Psychology, University of Finance and Management, Warsaw, Poland.
authors.forename: Rob H J
authors.initials: RH
authors.lastname: van der Lubbe
authors.affiliation: Donders Institute for Brain, Cognition, and Behaviour, Donders Centre for Cognition, Radboud University Nijmegen, Nijmegen, the Netherlands.
authors.forename: Ruud G J
authors.initials: RG
authors.lastname: Meulenbroek
authors.affiliation: Behavioural Science Institute, Radboud University Nijmegen, Nijmegen, the Netherlands.|School of Psychology, Australian Catholic University, Melbourne, Vic., Australia.
authors.forename: Bert
authors.initials: B
authors.lastname: Steenbergen
mesh_terms: D002547:Cerebral Palsy / Q000503:physiopathology*; D002648:Child; D004569:Electroencephalography; D005071:Evoked Potentials / Q000502:physiology*; D005260:Female; D006225:Hand / Q000503:physiopathology*; D006801:Humans; D007092:Imagination; D008297:Male; D009043:Motor Activity / Q000502:physiology*; D010364:Pattern Recognition, Visual / Q000502:physiology*; D011597:Psychomotor Performance / Q000502:physiology*; D012399:Rotation