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

Abstract EN

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.