Multiple schedules with response interruption and redirection to reduce stereotypy in children with autism spectrum disorder: Generalization and social validity

Although response interruption and redirection (RIRD) and multiple schedule arrangements have sometimes been shown to be effective in reducing stereotypy for individuals with autism spectrum disorder (ASD), important questions remain about optimal methods for facilitating generalization and social validity. In the current study, we sought to extend the literature on stereotypy treatment and MSAs in several ways. First, we programmed for generalization by conducting sessions with two exemplars of two different categories of activities (i.e., school work, toy play) and assessing generalization with novel exemplars and activities and during the participant's typical instructional program. Second, we used RIRD instructions that were contextual models of appropriate behavior relevant to each activity. Third, during the free access component of the multiple schedule, we used a child's play tent as a first step toward teaching participants to engage in stereotypy during private free time. For all three participants with ASD, stereotypy decreased quickly and substantially, with reductions generalizing to novel activities and contexts. An extensive social validity assessment with board-certified behavior analysts indicated high social acceptability of the goals, procedures, and outcomes.     

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).     

Effect of signaled reinforcement on response variability

Three experiments examined the effect of signaling reinforcement on rats' lever pressing on contingencies that reinforced variable responding to extend the exploration of signaled reinforcement to a schedule that has previously not been examined in this respect. In Experiment 1, rats responding on a lag-8 variability schedule with signaled reinforcement displayed greater levels of variability (U values) than rats on the same schedule lacking a reinforcement signal. In Experiment 2, rats responding on a differential reinforcement of least frequent responses schedule also displayed greater operant variability with a signal for reinforcement compared with rats without a reinforcement signal. In Experiment 3, a reinforcement signal decreased the variability of a response sequence when there was no variability requirement. These results offer empirical corroboration that operant variability responds to manipulations in the same manner as do other forms of operant response and that a reinforcement signal facilitates the emission of the required operant.     

Behavioral contrast: Research and areas for investigation

Behavioral contrast occurs when a change in reinforcement rate in one context results in a change in behavior in the opposite direction in an unchanged context. Despite decades of study by basic researchers, behavioral contrast has remained largely an unstudied phenomenon among applied researchers. The purpose of this paper is to occasion translational and applied research on behavioral contrast with the aim of predicting and controlling socially significant behavior in unchanged contexts. We present a brief history of contrast and related definitions, review research with human and nonhuman subjects, and suggest future directions for applied and translational researchers.     

Prevalence of resurgence of destructive behavior when thinning reinforcement schedules during functional communication training

Functional communication training is a well‐established treatment for socially reinforced destructive behavior that typically includes differential reinforcement of the functional communication response (FCR) in combination with extinction of destructive behavior. However, when the schedule of reinforcement for the FCR is thinned, destructive behavior may resurge (e.g., Greer, Fisher, Saini, Owen, & Jones, 2016). Currently, data are unavailable on the prevalence and characteristics of resurgence during reinforcement schedule thinning. In this study, we evaluated the prevalence of resurgence during reinforcement schedule thinning on a per‐case and per‐schedule‐step basis and also evaluated the magnitude of resurgence in relation to the functions of destructive behavior. We observed resurgence in 19 of the 25 (76%) applications of reinforcement schedule thinning. In some cases, the magnitude of resurgence exceeded the mean levels of destructive behavior observed in baseline. We discuss these results relative to prior translational and applied research on resurgence.     

Further investigation of differential reinforcement of alternative behavior without extinction for escape‐maintained destructive behavior

Previous research indicates that manipulating dimensions of reinforcement during differential reinforcement of alternative behavior (DRA) for situations in which extinction cannot be implemented is a potential approach for treating destructive behavior. Therefore, we replicated and extended previous research by determining (a) the conditions under which DRA without extinction decreased and maintained low levels of destructive behavior and (b) whether intervention effects maintained during reinforcement schedule thinning for the alternative response (i.e., compliance). Results showed that effective treatments were developed in the absence of extinction by manipulating the quality of reinforcement for compliance for 2 participants and by combining manipulations of the magnitude and quality of reinforcement for compliance for the other 2 participants. However, maintaining treatment effects during reinforcement schedule thinning required combining the magnitude and quality of reinforcement for 3 of the 4 participants. We discuss the clinical utility of this approach, review limitations of the study, and suggest directions for future research.     

Molecular Mechanisms Associated with the Benefits of Variable Practice in Motor Learning

Abstract

Variable practice promotes a higher level of motor learning than constant practice. The glutamate receptors, n-methyl-d-aspartate (NMDA) and alfa-amino-3-hydroxy-5-methyl-4-isoxazolepropionic (AMPA), have been associated with the changes in motor cortex that occur throughout the process of motor learning. Considering that, it is possible that variable practice is more associated with the NMDA and AMPA receptors than constant practice. This study aimed ao investigating the association between the glutamate receptors, NMDA and AMPA, and constant and variable practice schedules. Seventy-eight male mice practiced the rotarod task in a constant or variable scheduling, in two consecutive days (acquisition phase). Learning tests were performed 24?h and 10?days after the end of the acquisition phase. Variable practice was more associated with the NMDA receptor and had a greater AMPA receptor expression than constant practice. The results suggest that the benefits of variable practice are result of both the greater dependency on the NMDA receptor and the greater AMPA receptor expression.