The ability to rapidly stop one's actions even after their initiation is paramount to survival in modern society. Be it in benign scenarios (checking the swing of a baseball bat) or in life-threatening scenarios, rapid action-stopping is a core human ability that is highly relevant in everyday life. In this project, Dr. Wessel will use neural recordings and brain stimulation in adult healthy humans to further our understanding of how brain activity underlying motor emission (initiating an action) and motor inhibition (stopping that action) interact during the rapid stopping of action. Elucidating the neural interactions underlying action-stopping will inform our basic understanding of flexible behavior in both health and disease. This is especially relevant since action-stopping is significantly impaired across many neuropsychiatric disorders. During this project, Dr. Wessel will implement an educational opportunity at his institution that aims to provide a first-hand research experience in human neuroscience to first-generation college students, a population that is traditionally underrepresented in basic academic science and the STEM workforce.
The ability to stop the execution of an already initiated action is a key cognitive control ability. In prominent theoretical models, stopping is conceptualized as a race between a "go"-process and a separate "stop"-process that races to intercept the go-process. While extensive past research has established that a fronto-basal ganglia brain network implements the "stop" side of this equation, human research has so far fallen short of demonstrating the existence of an actual race between separate stop- and a go-processes in the brain. By combining measurements of intra- / extracranial electroencephalography and cortico-spinal excitability with brain stimulation, the project aims to elucidate neural concomitants of the purported race on all levels of processing (motor, cortical, subcortical). First, a pure neural measurement of the stopping process will be identified by disentangling neural processes that reflect stop-signal detection from those that reflect the stop-process itself. Second, this signature of the stop-process and an according measurement of the go-process will be used to predict behavior based on the trial-by-trial outcome of their neural race. Third, cortical and subcortical nodes of the neural network underlying the stop-process will be disrupted using transcranial magnetic and deep-brain stimulation to test the hypothesis that such disruptions impair motor inhibition specifically by biasing the race towards the "go" process.
This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
