UCSF

Understanding how the nervous system explores and then finds optimal solutions during the process of motor learning is fundamental for rational electrotherapy design. Plasticity in the motor cortex has been implicated in motor learning across a variety of tasks and model organisms. Translational approaches to modulating motor cortical activity have also demonstrated great potential for restoring or relearning motor tasks following brain injury. In this thesis, I begin in Chapter 1 by summarizing the modern understanding of the motor learning network, outlining how the primary motor cortex is uniquely positioned to regulate rapid adaptations to task demands. Then, I provide a historical perspective on brain stimulation methods used in humans for clinical and research applications, including the strengths and limitations and current approaches. In Chapter 2, I present a novel, translatable electrical brain stimulation technique – the ringtrode – which allows for the flexible and precise modulation of the primate cortex. In Chapter 3, I characterize the neural dynamics in motor cortex that underly rapid motor learning during brief breaks. Then, I apply the ringtrode to manipulate these dynamics and assess whether they are causal for motor learning. Finally, I present a model for how stimulation delivered via the ringtrode interacts with motor learning processes in the brain to explore why stimulation-induced effects on motor learning may depend on stimulation frequency.