Deep brain stimulation of the subthalamic nucleus modulates sensitivity to decision outcome value in Parkinson's disease.
Deep brain stimulation (DBS) of the subthalamic nucleus in Parkinson's disease is known to cause a subtle but important adverse impact on behaviour, with impulsivity its most widely reported manifestation. However, precisely which computational components of the decision process are modulated is not fully understood. Here we probe a number of distinct subprocesses, including temporal discount, outcome utility, instrumental learning rate, instrumental outcome sensitivity, reward-loss trade-offs, and perseveration. We tested 22 Parkinson's Disease patients both on and off subthalamic nucleus deep brain stimulation (STN-DBS), while they performed an instrumental learning task involving financial rewards and losses, and an inter-temporal choice task for financial rewards. We found that instrumental learning performance was significantly worse following stimulation, due to modulation of instrumental outcome sensitivity. Specifically, patients became less sensitive to decision values for both rewards and losses, but without any change to the learning rate or reward-loss trade-offs. However, we found no evidence that DBS modulated different components of temporal impulsivity. In conclusion, our results implicate the subthalamic nucleus in a modulation of outcome value in experience-based learning and decision-making in Parkinson's disease, suggesting a more pervasive role of the subthalamic nucleus in the control of human decision-making than previously thought.
Computational and Biological Learning Lab, Department of Engineering, University of Cambridge, UK.|Wellcome Trust Centre for Neuroimaging, UCL, London, UK.|Center for Information and Neural Networks, National Institute for Information and Communications Technology, Japan.
Ben
B
Seymour
Department of Neurology, University Hospital, Cologne, Germany.|Cognitive Neuroscience, Institute of Neuroscience and Medicine (INM-3), Research Centre, Jülich, Germany.
Michael
M
Barbe
Gatsby Computational Neuroscience Unit, UCL, London, UK.
Peter
P
Dayan
Wellcome Trust Centre for Neuroimaging, UCL, London, UK.
Tamara
T
Shiner
Wellcome Trust Centre for Neuroimaging, UCL, London, UK.
Ray
R
Dolan
Department of Neurology, University Hospital, Cologne, Germany.|Cognitive Neuroscience, Institute of Neuroscience and Medicine (INM-3), Research Centre, Jülich, Germany.
Gereon R
GR
Fink
D000368:Aged; D002755:Choice Behavior / Q000502:physiology; D003071:Cognition / Q000502:physiology; D003657:Decision Making / Q000502:physiology*; D046690:Deep Brain Stimulation / Q000009:adverse effects*; D005260:Female; D006801:Humans; D007175:Impulsive Behavior / Q000502:physiology; D007858:Learning / Q000502:physiology; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D010300:Parkinson Disease / Q000473:pathology / Q000503:physiopathology / Q000628:therapy*; D012201:Reward; D020531:Subthalamic Nucleus / Q000473:pathology / Q000503:physiopathology*