The investigators propose eleven experiments nested in three studies to examine variables related to behavioral inflexibility. The problem of inflexibility is defined as the maintenance of previously learned responses even when the environmental variables have changed, and no longer support those responses. It is hypothesized that individuals with autism and undifferentiated mental retardation experience abnormal inhibitory processes that increase the difficulty of rapid transitions from one behavior pattern to another. A four year plan of research is proposed to examine this problem through integration of research from stimulus control theory, matching law theory, and behavioral momentum theory. The major areas of study focus on three questions: (a) To what extent does cognitive inflexibility interact with response to reinforcement procedures?; (b) Will variations in teaching methodology allow one to minimize problems of cognitive inflexibility?; and (c) are improvements in cognitive flexibility achievable through training?
