Training context can influence resistance to disruption under differing reinforcement schedules. With nonhumans, when relatively lean and rich reinforcement schedules are experienced in the context of a multiple schedule, greater resistance is found in the rich than the lean component, as described by behavioral momentum theory. By contrast, when the schedules are experienced in separated blocks of sessions (i.e., as single schedules), resistance is not consistently greater in either component. In the current study, two groups of 6 children with intellectual disabilities responded to stimuli presented in relatively lean or rich components. For both, reinforcers were delivered according to the same variable-interval reinforcement schedule; additionally, the rich component included the delivery of response-independent reinforcers. The Within group was trained on a multiple schedule in which lean and rich components alternated regularly within sessions; the Blocked group was trained on two single schedules in which sessions with either the lean or rich schedule were conducted in successive blocks. Disruption tests presented a concurrently available alternative stimulus disrupter signaling the availability of tangible reinforcers. All 6 Within participants showed greater resistance to disruption in the rich component, consistent with behavioral momentum theory. By contrast, there was no consistent or significant difference in resistance for Blocked participants. This finding is potentially relevant to the development of interventions in applied settings, where such interventions often approximate single schedules and include response-independent reinforcers.

This study examined behavioral persistence during extinction following continuous or intermittent reinforcement in the context of an analogue functional analysis of problem behavior. Participants were 4 children who had been diagnosed with an autism spectrum disorder and who engaged in problem behavior maintained by social reinforcement. Experimental sessions included 4 successive 5-min components: no social interaction, continuous or intermittent reinforcement for problem behavior (alternating across sessions), extinction, and no social interaction. All participants' problem behavior was more persistent during extinction following continuous reinforcement, suggesting that behavior during extinction was affected by the preceding schedule of reinforcement.

Behavioral momentum theory states that behavioral resistance to change is positively related to reinforcer rate and independent of response rate under most circumstances. We examined behavioral momentum in humans with developmental disabilities. The experimental procedures were implemented as a computer game. Different rates of positive reinforcement were programmed in two alternating components signaled by distinctive cues. For 10 participants who successfully completed testing, resistance to disruption by an alternate source of reinforcement was greater in the component with the higher reinforcer rate, although the magnitude of the difference varied among individuals. These results confirm reinforcer rate effects consistent with behavioral momentum under laboratory conditions and with the largest number of human beings with developmental disabilities studied to date.