Increased variability in tacting under a lag 3 schedule of reinforcement

A systematic review of behaviour analytic interventions for young children with intellectual disabilities

BACKGROUND

According to several comprehensive systematic and narrative reviews, interventions based on applied behaviour analysis principles, or behaviour analytic interventions, are considered evidence based for children with autism spectrum disorder (ASD). However, no comprehensive review of the literature related to behaviour analytic interventions for children with intellectual disability (ID) currently exists.

METHODS

Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines (registration ID: CRD42018099317), the purpose of this study was to conduct a systematic review of the relevant published literature on the use of behaviour analytic interventions to develop skills in young children (0-8 years) with ID (and without ASD). A preliminary search of the literature identified 1209 potential studies published between January 2000 and April 2020. The review process resulted in 48 articles consisting of 49 studies (i.e. one paper contained two studies) that met the inclusion criteria. Most used single-case research designs. Studies were evaluated on five dimensions of methodological quality based on the Scientific Merit Rating Scale developed by the National Autism Center (NAC). The NAC definitions were also used for the quantity and quality of research evidence required for interventions to be considered established or emerging.

RESULTS

There were a number of limitations to the quality of the body of research. Nevertheless, various behaviour analytic interventions met criteria for being established interventions when used for targeting communication, adaptive and pre-academic skills in young children with ID. Behaviour analytic interventions targeting academic skills met criteria for emerging interventions.

CONCLUSIONS

Although the current literature is limited, results indicate that behaviour analytic interventions may be effectively used to support skill development in children with ID.

Using a Lag Schedule of Reinforcement to Increase Response Variability in Children With Autism Spectrum Disorders

Lag reinforcement schedules have been shown in previous research to be an effective intervention for teaching verbal and nonverbal response variability to individuals with developmental disabilities. In more recent research, variability itself has been considered a reinforceable behavior in its own right (Susa & Schlinger, The Analysis of Verbal Behavior, 18, 125-130, 2012). Lag x schedules of reinforcement can be used to teach variability by using contingencies that require responses to differ from previous responses. The present study extended Susa and Schlinger's, The Analysis of Verbal Behavior, 18, 125-130, (2012) research by using 3 social questions instead of 1 in a random rotation and included probes to test for generality. A changing-criterion design was used to evaluate the results with one 11-year-old female participant diagnosed with autism. During baseline, the participant provided little variability, with rote responses. During the Lag 1 and Lag 2 phases, appropriate variable verbal responding increased with the use of echoic prompts, visual aids, and an error correction procedure. Further, the results also showed that the participant learned to vary her responses by demonstrating the ability to emit 11 novel prompted responses and 13 spontaneous responses. In addition, the participant was able to retain the skills learned in a maintenance probe conducted 4 weeks postintervention.

Evaluation of Lag Schedules and Rules on Persistent Response Variability With Preschoolers in a Group

In the present study, experimenters evaluated the influence of lag schedules of reinforcement in combination with accurate and inaccurate (complete and incomplete) rules on the response variability of naming category items for typically developing preschoolers in a group format. Results showed that when lag schedules were introduced with 2 categories, response variability generalized to the third category. Furthermore, after participants experienced the lag schedule, variability persisted when the contingency no longer required variability. Participants continued to vary their responses unless the rule and contingency required them to repeat responses. We discuss potential clinical applications of using lag schedules in a group format and including rules during teaching, as well as directions for future research in this area.

A Critical Review of the Support for Variability as an Operant Dimension

There is abundant evidence that behavioral variability is more predominant when reinforcement is contingent on it than when it is not, and the interpretation of direct reinforcement of variability suggested by Page and Neuringer, Journal of Experimental Psychology: Animal Behavior Processes, 11(3), 429-452 (1985) has been widely accepted. Even so, trying to identify the underlying mechanisms in the emergence of stochastic-like variability in a variability contingency is intricate. There are several challenges to characterizing variability as directly reinforced, most notably because reinforcement traditionally has been found to produce repetitive responding, but also because directly reinforced variability does not always relate to independent variables the same way as more commonly studied repetitive responding does. The challenging findings in variability experiments are discussed, along with alternative hypotheses on how variability contingencies may engender the high variability that they undeniably do. We suggest that the typical increase in behavioral variability that is often demonstrated when reinforcement is contingent on it may be better explained in terms of a dynamic interaction of reinforcement and extinction working on several specific responses rather than as directly reinforced.

Replication and Extension of the Effects of Lag Schedules on Mand Variability and Challenging Behavior During Functional Communication Training

More is known about how to reduce challenging behavior with functional communication training (FCT) than how to mitigate its resurgence during or following a course of treatment. Research suggests reinforcing mand variability during FCT may mitigate the resurgence of challenging behavior, but validated procedures for reinforcing mand variability are limited and poorly understood. Lag schedules can reinforce variability in verbal behavior such as manding in individuals with autism, but studies have been largely limited to nonvocal mand modalities. Therefore, in the current study, we further evaluated the effects of FCT with lag schedules on vocal mand variability and challenging behavior in children with autism. The results suggest lag schedules alone or in combination with response prompt-fading strategies during FCT can increase mand variability and expand mand response classes but may fail to produce clinically significant reductions in challenging behavior.

An Evaluation of the Effects of Varying Magnitudes of Reinforcement on Variable Responding Exhibited by Individuals With Autism

Interventions aimed at increasing communicative response variability hold particular importance for individuals with autism spectrum disorders (ASD). Several procedures have been demonstrated in the applied and translational literature to increase response variability. However, little is known about the relationship between reinforcer magnitude and response variability. In the basic literature, Doughty, Giorno, and Miller evaluated the effects of reinforcer magnitude on behavioral variability by manipulating reinforcer magnitude across alternating relative frequency threshold contingencies, with results suggesting that larger reinforcers induced repetitive responding. The purpose of this study was to translate Doughty et al.'s findings to evaluate the relative effects of different magnitudes of reinforcement on communicative response variability in children with ASD. A Lag 1 schedule of reinforcement was in place during each condition within an alternating treatments design. Magnitudes of reinforcement contingent on variable communicative responding were manipulated across the two conditions. Inconsistent with basic findings, the results showed higher levels of variable communicative responding associated with the larger magnitude of reinforcement. These outcomes may have potential implications for interventions aimed at increasing response variability in individuals with ASD, as well as future research in this area.

An evaluation of lag schedules and prompting methods to increase variability of naming category items in children with autism spectrum disorder

A lag schedule of reinforcement is one way to increase response variability; however, previous research has been mixed with regard to the necessary parameters to increase variability. For some individuals, low schedule requirements (e.g., Lag 1) are sufficient to increase variability. For other individuals, higher lag schedules (e.g., Lag 3) or a lag schedule in combination with prompting is needed to increase variability. We evaluated the efficiency of different within-session progressive lag schedules to increase response variability with 2 children with autism. Results showed that increasing the lag criterion across sessions increased variability to levels similar to beginning with a high lag schedule for one participant. When lag schedules did not increase variability for the second participant, we compared a variety of prompting procedures. Results of the prompting evaluation showed that a tact-priming procedure was effective to increase varied responding.

Effects of a lag schedule of reinforcement with progressive time delay on topographical mand variability in children with autism

OBJECTIVE

Evaluate the effects of a Lag 1 schedule of reinforcement and progressive time delay (TD) on topographical mand variability in children with autism.

METHODS

Using single-subject design methodology, a multiple baseline across behaviors with embedded reversal design was employed. During Lag 0, reinforcement was delivered contingent on any independent instances of manding. During Lag 1 + TD, prompts were faded and reinforcement was delivered contingent on independent or prompted variant mand topographies.

RESULTS

Higher levels of topographical mand variability were observed during Lag 1 + TD for both participants.

CONCLUSIONS

A Lag 1 schedule of reinforcement with progressive TD increased variability across functionally equivalent vocal mand topographies for both participants. This finding extends prior literature by providing a novel model for studying reinforced mand variability in children, and by demonstrating how practitioners could use prompts and differential reinforcement to increase topographical mand variability in children with autism.

Lag Schedules and Functional Communication Training: Persistence of Mands and Relapse of Problem Behavior

We evaluated the effects of lag schedules of reinforcement and functional communication training (FCT) on mand variability and problem behavior in two children with autism spectrum disorder. Specifically, we implemented FCT with increasing lag schedules and compared its effects on problem behavior with baseline conditions. The results showed that both participants exhibited low rates of problem behavior during treatment relative to baseline during and following schedule thinning (up to a Lag 5 schedule arrangement). Variable and total mands remained high during schedule thinning. With one participant, variable manding persisted when the value of the lag schedule was reduced to zero. The current results are discussed in terms of implications for training multiple mand topographies during FCT for the potential prevention and/or mitigation of clinical relapse during challenges to treatment.

Enhancing appropriate and variable responding in young children with autism spectrum disorder

OBJECTIVE

The present study utilized lag schedules of reinforcement, in conjunction with training multiple exemplars and provision of prompts, to promote appropriate variability of social skills.

METHODS

Participants included in three children between the ages of 5 and 7 with ASD. Participants attended a social skills training program twice per week for eight weeks. A multiple probe design across target social skills was used to assess the effects of intervention.

RESULTS

Findings indicate that training multiple exemplars alone did not appreciably increase appropriate and variable responding, whereas the addition of lag schedules of reinforcement and prompting to training multiple exemplars resulted in appropriate and variable responding that exceeded baseline levels.

CONCLUSION

Use of lag schedule of reinforcement in conjunction with prompts was more effective than multiple exemplar training in isolation for increasing appropriate variability of social skills.

Application of a lag contingency to reduce perseveration on circumscribed interests

OBJECTIVE

To evaluate the effects of a lag reinforcement contingency on the conversation topics of children diagnosed with autism who perseverated on circumscribed interests (CIs).

METHOD

Single-case design study with two participants, age 11 and 12 years. A functional analysis employed an alternating-treatments design to assess effects of contingent attention on conversational behavior. A multiple-baseline with an embedded reversal design was employed in a subsequent lag contingency analysis, in which the conversation partner provided attention at the end of each 10 s interval if the content of the participant's conversation met the requirement of a Lag 0, Lag 1, or Lag 2 contingency.

RESULTS

The participants' conversational behavior was sensitive to a conversation-partner's attention as a consequence. Lag contingencies successfully altered the prevalence of CI-related and-unrelated talk.

CONCLUSION

Lag contingencies can shift conversation content away from CIs, but further research is needed to identify appropriate treatment goals with respect to variability and content.

An analysis of procedures that affect response variability

Response variability is sensitive to antecedent and consequent manipulations. Researchers have investigated inducement, direct production through reinforcement, and stimulus control of response variability. Recently, researchers have shown that lag reinforcement schedules reliably increase variability but may also produce higher-order stereotypy. There has been limited investigation of appropriate variability levels and alternation between repetition and variation. In a three-part study, we evaluated levels of variability across a group of children, the effects of various procedures on producing response variability and novelty, and the use of schedule-correlated stimuli for producing rapid alternation between repetition and variation. In Study 1, there was a nearly bimodal distribution of children emitting either low or high variability. In Study 2, for most children, fixed lag 4 and variable lag 4 schedules produced the highest levels of variability and novelty. In Study 3, responding was brought under control of schedule-correlated stimuli, allowing for rapid alternation between repetition and variation.

Authorship Trends in The Analysis of Verbal Behavior: 1982-2016

The Analysis of Verbal Behavior (TAVB) is the only journal focused on theoretical and empirical research in verbal behavior. An assessment of authorship trends can provide a critical perspective on practices in verbal behavior analysis (e.g., participation by non-US institutions, contributions by female authors). The present study examines authorship trends in all articles published in TAVB since its inception (between 1982 and 2016). All authors and their affiliations were listed and the first authors denoted as such. Authors were characterized as follows: prolificacy, new vs. frequent contributor status, number of co-authors, editor status, fellow status in a professional organization, and gender. Institutional affiliations were characterized as follows: academic vs. nonacademic institutions, prolificacy, and location (country). The review included 383 articles by 487 authors from 200 institutions. Our findings revealed areas in which TAVB is reaching maturity (e.g., author gender) and areas in which further action by contributors and editors is needed (e.g., international participation).

Teaching complex verbal operants to children with autism and establishing generalization using the peak curriculum

The present study evaluated the feasibility of the PEAK Relational Training System's Generalization Module (Dixon, 2014b) to teach and establish generalization of autoclitic mands, distorted tacts, and creative path finding in three children diagnosed with autism spectrum disorder. Using a multiple-baseline design across behaviors, each participant was provided with differential reinforcement and a least-to-most prompting hierarchy for correct responses to a subset of stimuli, and responses to other similar stimulus sets were probed for emergent generalization. Following training, each participant successfully acquired the directly trained behaviors and demonstrated generalization to the nonreinforced test exemplars. These data support the utility of Skinner's (1957) analysis to teach complex forms of verbal operants, and suggest that a manualized curriculum such as PEAK may have utility for promoting skill development and generalization for front line staff and caregivers of children with autism.

Using Instructive Feedback to Increase Response Variability During Intraverbal Training for Children with Autism Spectrum Disorder

We evaluated the effects of instructive feedback on the variability of intraverbal responses for two children with autism spectrum disorder. Specifically, we used an adapted alternating treatments design to compare participants' novel responses and response combinations during an intraverbal category program across conditions with and without instructive feedback. During instructive feedback, secondary targets were presented during the consequence event of the learning trial and consisted of a therapist's model of response variability. The results showed that participants engaged in more novel response combinations during instructive feedback conditions. We discussed the clinical implications of these results as well as areas for future research.

Promoting Accurate Variability of Social Skills in Children With Autism Spectrum Disorder

Restricted and repetitive behavior is a central feature of autism spectrum disorder (ASD), with such behaviors often resulting in lack of reinforcement in social contexts. The present study investigated training multiple exemplars of target behaviors and the utilization of lag schedules of reinforcement in the context of social skills training to promote appropriate and varied social behavior in children with ASD. Five participants with ASD between the ages of 7 and 9 attended a twice-weekly social skills group for 8 weeks. A multiple probe design across skills was utilized to assess intervention effects. During baseline, participants demonstrated low levels of skill accuracy and low appropriate variability in responding. During continuous reinforcement with one trained exemplar, skill accuracy increased while appropriate variability remained low. Training of three exemplars of target skills resulted in minimal improvements in appropriate variability. Introduction of a Lag 2 schedule with three trained exemplars was generally associated with increased appropriate variability. Further appropriate variability was observed during Lag 4 with three trained exemplars. Limitations and implications are discussed.