In Parkinson's disease on a probabilistic Go/NoGo task deep brain stimulation of the subthalamic nucleus only interferes with withholding of the most prepotent responses

Exp Brain Res. 2016 Apr;234(4):1133-43. doi: 10.1007/s00221-015-4531-2. Epub 2016 Jan 12.


The evidence on the impact of subthalamic nucleus deep brain stimulation (STN-DBS) on action restraint on Go/NoGO reaction time (RT) tasks in Parkinson's disease (PD) is inconsistent; with some studies reporting no effect and others finding that STN stimulation interferes with withholding of responses and results in more commission errors relative to STN-DBS off. We used a task in which the probability of Go stimuli varied from 100% (simple RT task) to 80, 50 and 20% (probabilistic Go/NoGo RT task), thus altering the prepotency of the response and the difficulty in withholding it on NoGo trials. Twenty PD patients with STN-DBS, ten unoperated PD patients and ten healthy controls participated in the study. All participants were tested twice; the order of on versus off stimulation for STN-DBS PD patients was counterbalanced. Both STN-DBS and unoperated PD patients were tested on medication. The results indicated that STN-DBS selectively decreased discriminability when the response was most prepotent (high--80%, as compared to low Go probability trials--50 and 20%). Movement times were faster with STN stimulation than with DBS off across different Go probability levels. There was neither an overall nor a selective effect of STN-DBS on RTs depending on the level of Go probability. Furthermore, compared to healthy controls, both STN-DBS and unoperated PD patients were more prone to making anticipatory errors; which was not influenced by STN stimulation. The results provide evidence for 'load-dependent' effects of STN stimulation on action restraint as a function of the prepotency of the Go response.

Keywords: Deep brain stimulation (DBS); Go/NoGo task; Load-dependent effects; Parkinson’s disease (PD); Prepotency; Subthalamic nucleus (STN).

MeSH terms

  • Aged
  • Deep Brain Stimulation / methods*
  • Female
  • Humans
  • Male
  • Middle Aged
  • Parkinson Disease / diagnosis*
  • Parkinson Disease / physiopathology
  • Parkinson Disease / surgery*
  • Photic Stimulation / methods*
  • Reaction Time / physiology*
  • Subthalamic Nucleus / physiology*