How can beta-blockers influence the formation of memories? Can beta-blockers erase memories entirely, or do these medications only affect the way or degree to which a memory is imprinted? Dr. James McGaugh, founding director of the Center for Neurobiology and Memory at the University of California, Irvine, explains the way beta-blockers can be used to treat post-traumatic stress disorder. What are the ethical concerns about pharmacologically manipulating our anxieties or stresses? Dr. Michael Greenberg hosts.