The purpose of this series of studies was to evaluate the effects of schedule thinning and delay-to-reinforcement following intervention for individuals diagnosed with intellectual and developmental disabilities. Study one was a systematic review of the available literature on schedule thinning, and study two evaluated the effects of a novel approach to delay-to-reinforcement following functional communication training. Results of both studies found that schedule thinning and delay-to-reinforcement are efficacious procedures for continued reductions in challenging behavior following intervention.

Individuals with intellectual and developmental disabilities, such as Autism Spectrum Disorder, often engage in challenging behavior that severely limits positive outcomes. Although treatment packages comprising functional communication training and multiple schedules of reinforcement have demonstrated great promise to both increase appropriate, socially acceptable communication responses for preferred items and decrease challenging behavior associated with not having access to preferred items, resurgence of challenging behavior has been reported to occur during lengthy periods when preferred items are not available (i.e., extinction). This study evaluated whether noncontingent access to an alternative item during an abrupt shift to a lengthy period of extinction would reduce the extent of challenging behavior. Two children with Autism Spectrum Disorder participated. The results of this study indicated that (a) functional communication training successfully reduced challenging behavior and increased the rate of functional communication responses (FCR) for both participants, (b) multiple schedules of reinforcement (i.e., signaled periods of reinforcement and extinction for FCRs) successfully produced discriminated FCRs, and (c) no major differences in challenging behavior were observed when alternative items were presented during the abrupt shift to a terminal period of extinction versus when alternative items were not presented. Limitations and future directions of research are discussed.

Noncontingent reinforcement (NCR) is a possible alternative to differential reinforcement of other behaviors (DRO) that may operate through a similar mechanism. In the research, the participant's problem behaviors were maintained by automatic reinforcement or even multiply maintained. NCR is the method to intervene with the participant who had no clinical effect on using sensory integration therapy (SIT) to reduce problem behaviors in the previous study. The results showed that NCR is an effective way to decrease the problem behaviors without extinction burst.