Synthesizing concurrent interval performances

Concurrent schedules may be viewed as consisting of two pairs of stay and switch schedules, each pair associated with one of the alternatives. A stay schedule arranges reinforcers for staying and responding at one alternative, whereas the associated switch schedule arranges reinforcers for switching to the other alternative. In standard concurrent schedules, the stay schedule at each alternative is equivalent to the switch schedule at the other alternative. MacDonall (1999) exposed rats to one pair of stay and switch variable-ratio schedules and varied the response requirements across conditions. Combining results from symmetric pairs produced composite performances that were described by the generalized matching law. This outcome was noteworthy because the data were obtained from performances at two alternatives with contingencies that were functionally unrelated to each other. This result suggests that concurrent performances may consist of two unrelated performances that alternate as behavior moves between alternatives. The purpose of the present experiment was to extend those results to interval schedules. Rats were exposed to pairs of random-interval schedules, and across conditions their mean intervals were varied. When data from appropriately paired conditions were combined, the composite performances were consistent with the generalized matching law. In addition, the results supported two models of concurrent performances that were based on local variables at an alternative (behavior, and stay and switch reinforcers): a modified version of the contingency discrimination model (Davison & Jenkins, 1985) and the local model (MacDonall, 1999).     

An evaluation of photographic activity schedules to increase independent playground skills in young children with autism

We used photographic activity schedules to increase the number of play activities completed by children with autism during unstructured time on the playground. All 3 participants engaged in more playground activities during and after training, and they continued to complete activities when novel photographs were introduced.     

Evaluation of a lag schedule of reinforcement in a group contingency to promote varied naming of categories items with children

We compared the effects of Lag 0 and Lag 1 schedules of reinforcement on children's responses naming category items in a group context and subsequent responses emitted during individual testing in which the schedule of reinforcement remained Lag 0. Specifically, we measured response variability and novel responses to categories for 3 children who demonstrated the lowest level of variability during an initial individual Lag 0 testing session. An additional 3 children who emitted a high level of variability during initial individual Lag 0 testing sessions served as peers during group sessions. Results showed that participants conformed to the Lag 1 schedule and were more likely to repeat peer responses in the group and during individual testing in the Lag 1 condition. Furthermore, the reinforcement schedule in effect during group sessions affected participants’ varied responses during individual testing, during which the reinforcement schedule remained unchanged.     

Divided stimulus control: Which key did you peck,or what color was it?

Responding on concurrent schedules produced a conditional discrimination (Phases 1 and 2), asking either which peck produced the event, or which color the keys were when the event was produced. In Phases 3 and 4, reinforcer delivery or a delay in blackout was interpolated between responding and the conditional discrimination. In Phase 1, location versus color discrimination accuracy was controlled by the relative reinforcer frequency for correct responses to these questions (divided stimulus control). In Phases 2 to 4, relative reinforcer frequency for correct responses to these questions was .5, and the relative frequency with which concurrent‐schedule responses produced the questions was varied. This variation had no clear effect on the accuracy of reporting Location or Color. These results are consistent with the model of divided control suggested by Davison and Elliffe (2010). Arranging a 3‐s reinforcer between responding and choice decreased both color and location accuracy, but a 3‐s delay only decreased location accuracy. Thus, in concurrent‐schedule performance, both ambient stimuli prior to a reinforcer and the location of the just‐reinforced response are available as discriminative stimuli following the reinforcer. Control of postreinforcer responding is divided between these according to their association with the relative frequency of subsequent reinforcers.     

A multicomponent approach to thinning reinforcer delivery during noncontingent reinforcement schedules

We evaluated a noncontingent reinforcement procedure that involved initially providing three subjects with signaled, continuous access to the functional reinforcer for aggression and slowly increasing the amount of time subjects were exposed to the signaled unavailability of the reinforcer. Additionally, alternative potential reinforcers were available throughout the sessions. Results showed immediate and substantial reductions in aggression for all three subjects. The clinical utility of this intervention is discussed, and future research directions are recommended.     

Functional analysis and treatment of problem behavior related to mands for rearrangement

This study is a systematic replication of a functional analysis (FA) of the relation between mands and problem behavior. We extended treatment approaches for this problem behavior function, and describe the treatment of problem behavior related to mands for rearrangement demonstrated by a 12‐year‐old girl with autism spectrum disorder and Smith‐Magenis syndrome. The mands consisted of requests for others to change their body positioning or proximity, or rearrange items back to their original position. An FA confirmed the relation between problem behavior and mand compliance, and functional communication training with extinction decreased problem behavior and increased functional communication responses. Problem behavior remained low as gradually longer nonreinforcement periods were introduced using a multiple schedule.