What makes extinction work: an analysis of procedural form and function.

We examined methods for determining how extinction should be applied to different functions of self-injurious behavior (SIB). Assessment data indicated that the head banging of 3 children with developmental disabilities was maintained by different reinforcement contingencies: One subject's SIB was positively reinforced by attention from adults, the 2nd subjects SIB was negatively reinforced by escape from educational tasks, and the 3rd subject's SIB appeared to be automatically reinforced or "self-stimulatory" in nature. Three functional variations of extinction--EXT (attention), EXT (escape), and EXT (sensory)--were evaluated, and each subject was exposed to at least two of these variations in reversal or multiple baseline designs. Reductions in SIB were observed only when implementation of "extinction" involved the discontinuation of reinforcement previously shown to be responsible for maintaining the behavior. These results highlight important differences among treatment techniques based on the same behavioral principle (extinction) when applied to topographically similar but functionally dissimilar responses, and further illustrate the practical implications of a functional analysis of behavior disorders for designing, selecting, and classifying therapeutic interventions.