Modulating Visuomotor Sequence Learning by Repetitive Transcranial Magnetic Stimulation: What Do We Know So Far?

Sequence learning and statistical learning are key components of predictive processes and many cognitive, motor, and social skills. The Serial Reaction Time Task (SRTT) can measure this fundamental cognitive process in the visuomotor domain. Repetitive transcranial magnetic stimulation (rTMS) is an increasingly used non-invasive brain stimulation method that can help us to determine the functional role of a given brain region. In this literature review, we systematically analyzed the eligible records (n = 17) that sought to modulate the performance on the SRTT with rTMS. The purpose of the analysis was to determine the effects of the following factors on SRTT performance: (1) stimulated brain areas, (2) rTMS protocols, (3) stimulated hemisphere, (4) timing of the stimulation, (5) SRTT sequence properties, and (6) other methodological features. We found that the two most promising target areas are the primary motor cortex (M1) and the dorsolateral prefrontal cortex (DLPFC). Low-frequency protocols over the M1 usually weakened performance, but the results are less consistent for the DLPFC. Our analysis of these six factors could help design future studies to modulate sequence learning by non-invasive brain stimulation.