Posttraining Dorsal Premotor cTBS and Devaluation-Based Action Control: No Detectable Difference From Vertex Stimulation.

Abstract

The neural basis of recently learned stimulus-response associations involves interactions between premotor, supplementary motor, sensorimotor, and striatal regions, but the causal contribution of premotor cortex to their posttraining expression remains unclear. Thirty-five right-handed volunteers learned six stimulus-response-outcome mappings in a single experimental session. Continuous theta-burst stimulation (cTBS) was then delivered over a right dorsal premotor target or a vertex active-control site before participants completed outcome-devaluation, slips-of-action, and baseline tests. The primary behavioral analyses showed no detectable group differences in reaction time or response accuracy during the outcome-devaluation or slips-of-action tests. Baseline performance was also comparable between groups, providing no evidence that stimulation affected retention of the recently learned mappings. Under the present limited-training protocol, posttraining cTBS over the right dorsal premotor target did not produce detectable behavioral differences relative to vertex cTBS. However, given the modest between-subject sample, the variability of devaluation-based measures, and the possibility that vertex stimulation affected adjacent medial motor regions, smaller or shared stimulation effects cannot be excluded.