L-Dopa infusion does not improve explicit sequence learning in Parkinson's disease

Parkinsonism Relat Disord. 2007 Apr;13(3):146-51. doi: 10.1016/j.parkreldis.2006.08.006. Epub 2006 Oct 20.


We have recently introduced a set of sequence learning tasks that emphasize explicit learning and target anticipation and involve the activation of frontal lobes. This type of learning is impaired even in the early stages of Parkinson's disease (PD). Studies on the effects of L-Dopa on cognitive symptoms of PD have yielded controversial results. To verify whether L-Dopa acutely improves explicit sequence learning, we tested six normal subjects and seven PD patients both off-drug and during L-Dopa infusion with two tasks: SEQ, a motor task with multiple demands, where a sequence had to be learned while reaching for a targets; VSEQ, a visual task where a sequence had to be learned by attending to a visual display without moving. Motor performance was assessed with simple motor tasks. L-Dopa improved motor scores and movement speed, but had no beneficial effect on either type of sequence learning.

Publication types

  • Clinical Trial
  • Research Support, N.I.H., Extramural

MeSH terms

  • Analysis of Variance
  • Antiparkinson Agents / pharmacology*
  • Antiparkinson Agents / therapeutic use
  • Female
  • Humans
  • Levodopa / pharmacology*
  • Levodopa / therapeutic use
  • Male
  • Middle Aged
  • Motor Activity / drug effects
  • Neuropsychological Tests
  • Parkinsonian Disorders / drug therapy
  • Parkinsonian Disorders / physiopathology*
  • Serial Learning / drug effects*
  • Severity of Illness Index


  • Antiparkinson Agents
  • Levodopa