| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 5626885 | Brain Stimulation | 2016 | 8 Pages |
•There are differential effects of HD-tDCS stimulation on sensorimotor rhythm based BCI performance and electrophysiology.•Anodal HD-tDCS decreased the time to hit correct targets during contralateral hand motor imagination.•Cathodal HD-tDCS decreased alpha and beta power during contralateral hand motor imagination trials compared to controls.•These effects should be considered when combining sensorimotor tDCS with tasks involving the motor cortex.
BackgroundTranscranial direct current stimulation (tDCS) has been used to alter the excitability of neurons within the cerebral cortex. Improvements in motor learning have been found in multiple studies when tDCS was applied to the motor cortex before or during task learning. The motor cortex is also active during the performance of motor imagination, a cognitive task during which a person imagines, but does not execute, a movement. Motor imagery can be used with noninvasive brain computer interfaces (BCIs) to control virtual objects in up to three dimensions, but to master control of such devices requires long training times.ObjectiveTo evaluate the effect of high-definition tDCS on the performance and underlying electrophysiology of motor imagery based BCI.MethodsWe utilize high-definition tDCS to investigate the effect of stimulation on motor imagery-based BCI performance across and within sessions over multiple training days.ResultsWe report a decreased time-to-hit with anodal stimulation both within and across sessions. We also found differing electrophysiological changes of the stimulated sensorimotor cortex during online BCI task performance for left vs. right trials. Cathodal stimulation led to a decrease in alpha and beta band power during task performance compared to sham stimulation for right hand imagination trials.ConclusionThese results suggest that unilateral tDCS over the sensorimotor motor cortex differentially affects cortical areas based on task specific neural activation.
