Michelle A. Frank-Crawford

Examination of the influence of contingency on changes in reinforcer value.

This study examined how the amount of effort required to produce a reinforcer influenced subsequent preference for, and strength of, that reinforcer in 7 individuals with intellectual disabilities. Preference assessments identified four moderately preferred stimuli for each participant, and progressive-ratio (PR) analyses indexed reinforcer strength. Stimuli were then assigned to one of four conditions for 4 weeks: fixed-ratio (FR) 1 schedule, escalating FR schedule, yoked noncontingent (NCR) delivery, and restricted access. Preference assessments and PR schedules were then repeated to examine changes in selection percentages and PR break points. Selection percentages decreased for all NCR stimuli but increased for most of the restricted stimuli. There were no systematic changes in selection percentages for either of the contingent stimuli. Break points increased, on average, for all conditions, but the increase was highest for the restricted stimuli and lowest for the NCR stimuli. These results are discussed in relation to recent basic research addressing the influence of effort on stimulus value.

Effects of signaled and unsignaled alternative reinforcement on persistence and relapse in children and pigeons.

Three experiments explored the impact of different reinforcer rates for alternative behavior (DRA) on the suppression and post-DRA relapse of target behavior, and the persistence of alternative behavior. All experiments arranged baseline, intervention with extinction of target behavior concurrently with DRA, and post-treatment tests of resurgence or reinstatement, in two- or three-component multiple schedules. Experiment 1, with pigeons, arranged high or low baseline reinforcer rates; both rich and lean DRA schedules reduced target behavior to low levels. When DRA was discontinued, the magnitude of relapse depended on both baseline reinforcer rate and the rate of DRA. Experiment 2, with children exhibiting problem behaviors, arranged an intermediate baseline reinforcer rate and rich or lean signaled DRA. During treatment, both rich and lean DRA rapidly reduced problem behavior to low levels, but post-treatment relapse was generally greater in the DRA-rich than the DRA-lean component. Experiment 3, with pigeons, repeated the low-baseline condition of Experiment 1 with signaled DRA as in Experiment 2. Target behavior decreased to intermediate levels in both DRA-rich and DRA-lean components. Relapse, when it occurred, was directly related to DRA reinforcer rate as in Experiment 2. The post-treatment persistence of alternative behavior was greater in the DRA-rich component in Experiment 1, whereas it was the same or greater in the signaled-DRA-lean component in Experiments 2 and 3. Thus, infrequent signaled DRA may be optimal for effective clinical treatment.

Distributed and accumulated reinforcement arrangements: Evaluations of efficacy and preference

We assessed the efficacy of, and preference for, accumulated access to reinforcers, which allows uninterrupted engagement with the reinforcers but imposes an inherent delay required to first complete the task. Experiment 1 compared rates of task completion in 4 individuals who had been diagnosed with intellectual disabilities when reinforcement was distributed (i.e., 30-s access to the reinforcer delivered immediately after each response) and accumulated (i.e., 5-min access to the reinforcer after completion of multiple consecutive responses). Accumulated reinforcement produced response rates that equaled or exceeded rates during distributed reinforcement for 3 participants. Experiment 2 used a concurrent-chains schedule to examine preferences for each arrangement. All participants preferred delayed, accumulated access when the reinforcer was an activity. Three participants also preferred accumulated access to edible reinforcers. The collective results suggest that, despite the inherent delay, accumulated reinforcement is just as effective and is often preferred by learners over distributed reinforcement.

Reinforcement Arrangements for Learners with Autism Spectrum Disorder

Reinforcement is a process by which a consequence, a reinforcer, follows a response and increases the future likelihood of that response under similar conditions. Parents, teachers, clinicians, and other caregivers use reinforcement-based procedures in educational and therapeutic arrangements for individuals with autism spectrum disorder (ASD) to increase desirable behavior and to reduce the frequency of undesirable behavior. The precision and ultimate success of these procedures depends on selecting the right reinforcers and arranging their delivery in an effective fashion. Thus, understanding how to identify and arrange reinforcers, as well as the variables that influence the effectiveness of reinforcers, are critical to designing and implementing effective reinforcement-based interventions.

A quantitative review of overjustification effects in persons with intellectual and developmental disabilities.

The overjustification hypothesis suggests that extrinsic rewards undermine intrinsic motivation. Extrinsic rewards are common in strengthening behavior in persons with intellectual and developmental disabilities; we examined overjustification effects in this context. A literature search yielded 65 data sets permitting comparison of responding during an initial no-reinforcement phase to a subsequent no-reinforcement phase, separated by a reinforcement phase. We used effect sizes to compare response levels in these two no-reinforcement phases. Overall, the mean effect size did not differ from zero; levels in the second no-reinforcement phase were equally likely to be higher or lower than in the first. However, in contrast to the overjustification hypothesis, levels were higher in the second no-reinforcement phase when comparing the single no-reinforcement sessions immediately before and after reinforcement. Outcomes consistent with the overjustification hypothesis were somewhat more likely when the target behavior occurred at relatively higher levels prior to reinforcement.

Examining the reinforcing value of stimuli within social and non-social contexts in children with and without high-functioning autism

One of the key diagnostic criteria for autism spectrum disorder includes impairments in social interactions. This study compared the extent to which boys with high-functioning autism and typically developing boys “value” engaging in activities with a parent or alone. Two different assessments that can empirically determine the relative reinforcing value of social and non-social stimuli were employed: paired-choice preference assessments and progressive-ratio schedules. There were no significant differences between boys with high-functioning autism and typically developing boys on either measure. Moreover, there was a strong correspondence in performance across these two measures for participants in each group. These results suggest that the relative reinforcing value of engaging in activities with a primary caregiver is not diminished for children with autism spectrum disorder.

Copy Number Variants Associated with 14 Cases of Self-Injurious Behavior.

Copy number variants (CNVs) were detected and analyzed in 14 probands with autism and intellectual disability with self-injurious behavior (SIB) resulting in tissue damage. For each proband we obtained a clinical history and detailed behavioral descriptions. Genetic anomalies were observed in all probands, and likely clinical significance could be established in four cases. This included two cases having novel, de novo copy number variants and two cases having variants likely to have functional significance. These cases included segmental trisomy 14, segmental monosomy 21, and variants predicted to disrupt the function of ZEB2 (encoding a transcription factor) and HTR2C (encoding a serotonin receptor). Our results identify variants in regions previously implicated in intellectual disability and suggest candidate genes that could contribute to the etiology of SIB.

A tribute to sidney w. Bijou, pioneer in behavior analysis and child development: key works that have transformed behavior analysis in practice.

Sidney W. Bijou’s contributions to the practice of behavior analysis spanned nearly 7 decades, and they continue to influence what is considered “best practice” in our field today. By extending basic behavioral phenomena conducted with nonhuman animals to children in laboratory and naturalistic settings, Bijou’s early research sparked a watershed of similar extensions. More importantly, Bijou’s approach has led to a greater understanding of child development and behavior. This tribute will highlight what may be three of Bijou’s most significant contributions to practice, namely his studies on (a) programmed instruction for children with developmental disabilities (Bijou, Birnbrauer, Kidder, & Tague, 1966), (b) children’s responding under schedules of reinforcement and extinction (Bijou, 1957), and (c) the use of descriptive analysis to identify functional relations (Bijou, Peterson, & Ault, 1968).

Additional free reinforcers increase persistence of problem behavior in a clinical context: A partial replication of laboratory findings

Behavioral momentum theory is a quantitative framework used to characterize the persistence of behavior during response disruptors as a function of baseline stimulus-reinforcer relations. Results of several investigations have shown that alternative reinforcement can increase the resistance to change of a target response during extinction. In the present study, concomitant variable-interval fixed-time schedules of reinforcement for problem behavior were employed to simulate naturalistic situations involving the superimposition of response-independent reinforcers on a baseline schedule of reinforcement for problem behavior, as in the common use of noncontingent reinforcement treatments. Resistance to change of problem behavior was assessed during postsession periods of extinction by comparing response rates in extinction following sessions with and without additional reinforcer deliveries arranged by fixed-time schedules. For 2 out of 3 participants, problem behavior tended to be more resistant to extinction following periods in which additional fixed-time reinforcers were delivered. These results are discussed in terms of potential effects of noncontingent reinforcement on problem behavior when the intervention is discontinued or implemented without good treatment integrity.

Does preference rank predict substitution for the reinforcer for problem behavior? a behavioral economic analysis: PREFERENCE RANK AND DEMAND

Predictions made under low response requirements inherent in most preference assessments (PAs) do not guarantee the utility of stimuli in treatments. We examined whether PA rank would predict how well stimuli supported compliance for children with escape-maintained problem behavior by examining the relation between PA rank and demand elasticity across five fixed-ratio values. Three patterns were observed: All stimuli were selected equally across values, higher ranked stimuli were selected more at higher values, and something other than the highest ranked stimulus was selected more at higher values (i.e., mixed correspondence).