Functional Roles of Dorsolateral Prefrontal Cortex

The purpose of this study is to test the functions of dorsolateral prefrontal cortex in human motor learning. Dorsolateral prefrontal cortex (DLPFC) has been found to be involved in cognitive functions such as executive function, response selection, and working memory. Recent Findings hint potential involvement of dorsolateral prefrontal cortex in motor learning. Rare studies provided supporting evidence on its involvement and functions. This study aims to examine the functional roles of dorsolateral prefrontal cortex in human motor learning. By applying transcranial magnetic stimulation (TMS) or transcranial focused ultrasound (FUS), which is a technology to temporally alter brain state in the stimulation site, the investigators aim to find supporting evidence for the causal relationship between the targeted stimulation site and motor learning improvement or response selection.

Young healthy adults will be recruited and randomly assigned to one of four experimental groups. If randomized into one of the TMS groups, participants will learn to adapt to two visual rotations (20 and 60 degrees) when reaching for a virtual target, subjects will receive repetitive TMS (rTMS) stimulation over the targeted location, left DLPFC, or right DLPFC depending on the study group. How rTMS stimulation influencing the acquisition and retention of motor memory will be assessed based on group comparison of behavioral measures such as reaching accuracy. If randomized into the FUS group, participants will complete a flanker task to focuses on the assessment of response selection and inhibitory control.