Dissociation of 'on-line' and 'off-line' visuomotor control of the arm by focal lesions in the cerebellum and brainstem

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Colleges, School and Institutes

External organisations

  • University of Oxford
  • Radcliffe Infirmary


Visuomotor control of the arm was assessed in a single case study of a subject with focal lesions in the cerebellum and brainstem. A dissociation between 'on-line' and 'off-line' visuomotor control was revealed: impairments in 'on-line' visuomotor control included inaccuracy of tracking velocity, increase in spatial pointing variability and a delay in simple reaction time; whereas the patient was able to adapt to a gain change in 'off-line' visual feedback during a pointing task, and his adaptation was less affected than that of control subjects by trial-to-trial random fluctuations in 'off-line' visual feedback. We conclude that focal damage in the cerebellar peduncles may be principally responsible for this dissociation.


Original languageEnglish
Pages (from-to)121-124
Number of pages4
JournalNeuroscience Letters
Issue number1-3
Publication statusPublished - 2 Apr 1999


  • Adaptation, Brainstem, Cerebellum, Tracking, Visuomotor control

ASJC Scopus subject areas