The 4 years that Michel Hersen spent at the University of Mississippi Medical Center (1970-1974) are described in this article from the viewpoint of his place in the history of the development of behavior analysis and therapy. The Department of Psychiatry at the University of Mississippi Medical Center became a leader in enhancing the role of…

Behavioral momentum theory provides a quantitative account of how reinforcers experienced within a discriminative stimulus context govern the persistence of behavior that occurs in that context. The theory suggests that all reinforcers obtained in the presence of a discriminative stimulus increase resistance to change, regardless of whether those…