Cerebellar Cathodal Transcranial Direct Stimulation and Performance on a Verb Generation Task: A Replication Study

Neural Plast. 2017:2017:1254615. doi: 10.1155/2017/1254615. Epub 2017 Feb 14.

Abstract

The role of the cerebellum in cognitive processing is increasingly recognized but still poorly understood. A recent study in this field applied cerebellar Transcranial Direct Current Stimulation (c-tDCS) to the right cerebellum to investigate the role of prefrontal-cerebellar loops in language aspects of cognition. Results showed that the improvement in participants' verbal response times on a verb generation task was facilitated immediately after cathodal c-tDCS, compared to anodal or sham c-tDCS. The primary aim of the present study is to replicate these findings and additionally to investigate possible longer term effects. A crossover within-subject design was used, comparing cathodal and sham c-tDCS. The experiment consisted of two visits with an interval of one week. Our results show no direct contribution of cathodal c-tDCS over the cerebellum to language task performance. However, one week later, the group receiving cathodal c-tDCS in the first visit show less improvement and increased variability in their verbal response times during the second visit, compared to the group receiving sham c-tDCS in the first visit. These findings suggest a potential negative effect of c-tDCS and warrant further investigation into long term effects of c-tDCS before undertaking clinical studies with poststroke patients with aphasia.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Cerebellum / physiology*
  • Cross-Over Studies
  • Double-Blind Method
  • Female
  • Humans
  • Learning / physiology*
  • Male
  • Photic Stimulation / methods
  • Pilot Projects
  • Psychomotor Performance / physiology*
  • Reaction Time / physiology
  • Reading*
  • Transcranial Direct Current Stimulation / adverse effects
  • Transcranial Direct Current Stimulation / methods*
  • Verbal Behavior / physiology*
  • Vocabulary
  • Young Adult