Brendan Walker headshot (IMAGE) University of South Florida (USF Health) Caption Study principal investigator Brendan Walker, PhD, a neuroscientist at the University of South Florida Health (USF Health) Morsani College of Medicine, studies biological brain changes that drive addictive behaviors. Credit USF Health/University of South Florida Usage Restrictions Please use photo with appropriate caption. License Original content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.