Dorsal striatum does not mediate feedback-based, stimulus-response learning: An event-related fMRI study in patients with Parkinson's disease tested on and off dopaminergic therapy

Neuroimage. 2019 Jan 15:185:455-470. doi: 10.1016/j.neuroimage.2018.10.045. Epub 2018 Oct 27.

Abstract

Learning associations between stimuli and responses is essential to everyday life. Dorsal striatum (DS) has long been implicated in stimulus-response learning, though recent results challenge this contention. We have proposed that discrepant findings arise because stimulus-response learning methodology generally confounds learning and response selection processes. In 19 patients with Parkinson's disease (PD) and 18 age-matched controls, we found that dopaminergic therapy decreased the efficiency of stimulus-response learning, with corresponding attenuation of ventral striatum (VS) activation. In contrast, exogenous dopamine improved response selection accuracy related to enhanced DS BOLD signal. Contrasts between PD patients and controls fully support these within-subject patterns. These double dissociations in terms of behaviour and neural activity related to VS and DS in PD and in response to dopaminergic therapy, strongly refute the view that DS mediates stimulus-response learning through feedback. Our findings integrate with a growing literature favouring a role for DS in decision making rather than learning, and unite two literature that have been evolving independently.

Keywords: Decision making; Dopamine; Dorsal striatum; Functional magnetic resonance imaging; Ventral striatum.

Publication types

  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Antiparkinson Agents / therapeutic use
  • Association Learning / drug effects*
  • Association Learning / physiology*
  • Brain Mapping / methods
  • Corpus Striatum / drug effects*
  • Corpus Striatum / physiopathology
  • Decision Making / drug effects
  • Decision Making / physiology
  • Evoked Potentials / drug effects
  • Evoked Potentials / physiology
  • Female
  • Formative Feedback
  • Humans
  • Levodopa / therapeutic use*
  • Magnetic Resonance Imaging
  • Male
  • Parkinson Disease / drug therapy
  • Parkinson Disease / physiopathology
  • Parkinson Disease / psychology*

Substances

  • Antiparkinson Agents
  • Levodopa