title: No consistent effect of cerebellar transcranial direct current stimulation on visuomotor adaptation.
abstract: Cerebellar transcranial direct current stimulation (ctDCS) is known to enhance adaptation to a novel visual rotation (visuomotor adaptation), and it is suggested to hold promise as a therapeutic intervention. However, it is unknown whether this effect is robust across varying task parameters. This question is crucial if ctDCS is to be used clinically, because it must have a consistent and robust effect across a relatively wide range of behaviors. The aim of this study was to examine the effect of ctDCS on visuomotor adaptation across a wide range of task parameters that were systematically varied. Therefore, 192 young healthy individuals participated in 1 of 7 visuomotor adaptation experiments in either an anodal or sham ctDCS group. Each experiment examined whether ctDCS had a positive effect on adaptation when a unique feature of the task was altered: position of the monitor, offline tDCS, use of a tool, and perturbation schedule. Although we initially replicated the previously reported positive effect of ctDCS on visuomotor adaptation, this was not maintained during a second replication study or across a large range of varying task parameters. At the very least, this may call into question the validity of using ctDCS within a clinical context where a robust and consistent effect across behavior would be required.NEW & NOTEWORTHYCerebellar transcranial direct current stimulation (ctDCS) is known to enhance motor adaptation and thus holds promise as a therapeutic intervention. However, understanding the reliability of ctDCS across varying task parameters is crucial. To examine this, we investigated whether ctDCS enhanced visuomotor adaptation across a range of varying task parameters. We found ctDCS to have no consistent effect on visuomotor adaptation, questioning the validity of using ctDCS within a clinical context.
authors.affiliation: Physical Sciences of Imaging in the Biomedical Sciences, Doctoral Training Centre, University of Birmingham, Birmingham, United Kingdom; and rxj237@bham.ac.uk Royadjalali@gmail.com.|School of Psychology, University of Birmingham, Birmingham, United Kingdom.
authors.forename: Roya
authors.initials: R
authors.lastname: Jalali
authors.affiliation: School of Psychology, University of Birmingham, Birmingham, United Kingdom.
authors.forename: R Chris
authors.initials: RC
authors.lastname: Miall
authors.affiliation: School of Psychology, University of Birmingham, Birmingham, United Kingdom.
authors.forename: Joseph M
authors.initials: JM
authors.lastname: Galea
mesh_terms: D000222:Adaptation, Physiological / Q000502:physiology*; D000223:Adaptation, Psychological / Q000502:physiology; D000328:Adult; D002531:Cerebellum / Q000502:physiology*; D005260:Female; D006225:Hand / Q000502:physiology; D006801:Humans; D008297:Male; D009043:Motor Activity / Q000502:physiology*; D009483:Neuropsychological Tests; D015203:Reproducibility of Results; D065908:Transcranial Direct Current Stimulation; D014796:Visual Perception / Q000502:physiology*
keywords: adaptation; brain stimulation; cerebellum; motor learning; tDCS