The study proposed herein will be used primarily to examine the utility of biofeedback as an assessment tool in the clinical management of sport-related concussion. However, a number of secondary objectives will also be served by this proposed research endeavor. First, the study will seek to further explore the relationship between cerebral blood flow following sport-related concussion and mild traumatic brain injuries (mTBI) in a sample of high school and collegiate athletes. Moreover, the results generated by the study may be helpful in creating future areas of investigation as well as potentially establishing best practices for promoting more effective and efficient recovery following sport-related concussion. The conceptual understanding of concussion is now widely accepted as metabolic in nature, with identified neurophysiological pathology being at the root of symptom presentations rather than the structural damage that is often associated with moderate or severe brain injury. As a result, conventional structural neuroimaging studies such as computerized tomography (CT) and magnetic resonance imaging (MRI) routinely produce unremarkable findings in sport-related concussion and mTBI. Within the sport concussion literature, there is a call for a more precise and accurate methods for diagnosing an injured athlete who may have suffered a concussion during competition or off -field activities. With an eye toward potential intervention strategies that could promote more efficient recovery following mild brain injury, the authors seek to determine whether the latest biofeedback techniques can be used to demonstrate reliable and measurable physiological markers that are associated with sport-related concussion. Given the work that researchers have done in demonstrating the pathophysiological changes that follow sport-related concussion, one would expect that biofeedback might be a useful and more cost-efficient means of identifying associated metabolic changes.