A significant number of soldiers are returning from conflicts in Iraq and Afghanistan with Post-Concussion Syndrome (PCS) and continue to exhibit symptoms that result from a concussion. PCS is often difficult to diagnose because there are no externally visible injuries, and a concussion, also known as a mild traumatic brain injury or mTBI, does not show up on standard imaging scans. Researchers in Auburn University’s Samuel Ginn College of Engineering are partnering with psychologists in Auburn’s Department of Psychology, the U.S. Army Aeromedical Research Lab at Fort Rucker, Ala., and the TBI clinic at Fort Benning, Ga., to use functional magnetic resonance imaging (fMRI) to study PCS. Participants in the study undergo a series of brain scans that analyze the anatomical structures of the brain and the fiber tracts that connect these structures, which can reveal differences in the brain architecture between PCS and healthy participants. In addition, patients undergo fMRI scans to measure brain activity that focuses on soldiers’ ability to regulate their emotions, a problem from which many PCS patients suffer. Soldiers are shown images from conflicts in Iraq and Afghanistan and are asked to suppress, maintain or amplify their emotional response to these images while their brains are scanned with a technique that measures blood flow to activated regions of the brain. Preliminary results indicate that fMRI is able to measure an increase in effort by PCS patients when regulating their emotions, which may, along with standard neuropsychological testing and genomic analysis, potentially be an objective test, called a biomarker, for PCS. Determining such a biomarker may ultimately aid the diagnosis and treatment of this disorder.