rTMS Induced Reduction in M1 Excitability

Overview

When learning a new skill, much of the improvement comes from small alterations the brain makes with each repetition during practice, but this isn't the only time that improvements are made during the learning process. Individuals also get better at the motor skills during the time between practices, through a process called "consolidation." It is known that an area of the brain called the primary motor cortex is involved in learning during active practice, but the investigators want to study if the primary motor cortex is important for consolidation. The investigators will examine how lowering the activity in this brain region affects your ability to consolidate learning to play a song on the videogame Guitar Hero.

Research employing rTMS-induced reductions in excitability showed that M1 had a large role in consolidation after practice, but was not responsible for the improvements that occur during practice. Though this study used a simple finger tapping task, additional studies have shown the role of M1 in task consolidation with ballistic movements and dynamic force-field learning tasks, while using rTMS to reduce cortical excitability. The main issue with previous studies is that they have been limited to a single digit, single joint, or non-transferrable laboratory tasks. This limits the application of these studies to real world scenarios, and shows the need for further research into this interaction. Therefore, we intend to examine the effect of an rTMS-induced reduction in M1 excitability, on the learning of a dynamic, two-handed video game task (Guitar Hero). This is important because it will help explain the role of M1 in learning complex, bimanual tasks. Our study will also directly address how M1 contributes to the fast and slow consolidation of dynamic, coordinated actions that more closely resemble real-world activities (video games). Ultimately, this knowledge is crucial to the development of targeted non-invasive brain stimulation protocols that could aid in the rehabilitation of patients with motor dysfunction, in which relearning complex coordinated motor tasks is a primary goal. Objective(s) 1. Primary Objective Our primary objective is to determine if short term inhibition of M1 with 1Hz rTMS (rTMS induced reductions in excitability) blocks the early online learning (fast and slow consolidation) that occurs when first playing a video game 2. Secondary Objective Our secondary objective is to compare the amount of rTMS-induced reductions in excitability, measured with single pulse TMS motor-evoked potential cortical excitability, with the amount of fast and slow consolidation observed in playing the video game.