Subthalamic nucleus local field potential activity during the Eriksen flanker task reveals a novel role for theta phase during conflict monitoring

Research output: Contribution to journalArticle

Authors

  • Baltazar Zavala
  • Keyoumars Ashkan
  • Thomas Foltynie
  • Patricia Limousin
  • Ludvic Zrinzo
  • Alexander L Green
  • Tipu Aziz
  • Kareem Zaghloul
  • Peter Brown

External organisations

  • Functional Neurosurgery-Experimental Neurology Group, Nuffield Department of Clinical Neurology, University of Oxford John Radcliffe Hospital, Oxford OX3 9DU, United Kingdom, Surgical Neurology Branch, National Institutes of Health, Bethesda, Maryland 20814, Department of Neurosurgery, King's College Hospital, Kings College, London SE5 9RS, United Kingdom, and Sobell Department of Motor Neuroscience and Movement Disorders, UCL Institute of Neurology, London WC1 3BG, United Kingdom.

Abstract

The subthalamic nucleus (STN) is thought to play a central role in modulating responses during conflict. Computational models have suggested that the location of the STN in the basal ganglia, as well as its numerous connections to conflict-related cortical structures, allows it to be ideally situated to act as a global inhibitor during conflict. Additionally, recent behavioral experiments have shown that deep brain stimulation to the STN results in impulsivity during high-conflict situations. However, the precise mechanisms that mediate the "hold-your-horses" function of the STN remain unclear. We recorded from deep brain stimulation electrodes implanted bilaterally in the STN of 13 human subjects with Parkinson's disease while they performed a flanker task. The incongruent trials with the shortest reaction times showed no behavioral or electrophysiological differences from congruent trials, suggesting that the distracter stimuli were successfully ignored. In these trials, cue-locked STN theta band activity demonstrated phase alignment across trials and was followed by a periresponse increase in theta power. In contrast, incongruent trials with longer reaction times demonstrated a relative reduction in theta phase alignment followed by higher theta power. Theta phase alignment negatively correlated with subject reaction time, and theta power positively correlated with trial reaction time. Thus, when conflicting stimuli are not properly ignored, disruption of STN theta phase alignment may help operationalize the hold-your-horses role of the nucleus, whereas later increases in the amplitude of theta oscillations may help overcome this function.

Details

Original languageEnglish
Pages (from-to)14758-66
Number of pages9
JournalThe Journal of Neuroscience
Volume33
Issue number37
Publication statusPublished - 11 Sep 2013

Keywords

  • Aged, Brain Mapping, Cognition Disorders, Conflict (Psychology), Contingent Negative Variation, Cues, Deep Brain Stimulation, Electroencephalography, Female, Humans, Male, Middle Aged, Neuropsychological Tests, Parkinson Disease, Reaction Time, Subthalamic Nucleus, Theta Rhythm, Journal Article, Research Support, Non-U.S. Gov't