L-dopa impairs learning, but spares generalization, in Parkinson's disease

Daphna Shohamy, Catherine Myers, Kindiya D. Geghman, Jacob Sage, Mark Gluck

Research output: Contribution to journalArticlepeer-review

124 Scopus citations


In this study we examined the effect of dopaminergic modulation on learning and memory. Parkinson's patients were tested 'on' versus 'off' dopaminergic medication, using a two-phase learning and transfer task. We found that dopaminergic medication was associated with impaired learning of an incrementally acquired concurrent discrimination task, while patients withdrawn from dopaminergic medication performed as well as controls. In addition, we found a dissociation of the effect of medication within a single two-phase task: patients tested 'on' medication were not impaired at the ability to generalize based on learned information. The deficit among medicated patients appeared to be related specifically to the concurrent, incremental, feedback-based nature of the task: such a deficit was not found in a version of the task in which demands for concurrent error-processing learning were reduced. Taken together with a growing body of evidence emphasizing a role for midbrain dopamine in error-correcting, feedback-based learning processes, the present results suggest a framework for understanding previously conflicting results regarding the effect of medication on learning and memory in Parkinson's disease.

Original languageEnglish (US)
Pages (from-to)774-784
Number of pages11
Issue number5
StatePublished - 2006

All Science Journal Classification (ASJC) codes

  • Experimental and Cognitive Psychology
  • Cognitive Neuroscience
  • Behavioral Neuroscience


  • Basal ganglia
  • Cognition
  • Dopamine
  • Learning
  • Memory

Fingerprint Dive into the research topics of 'L-dopa impairs learning, but spares generalization, in Parkinson's disease'. Together they form a unique fingerprint.

Cite this