Lag Schedules Research Articles

Lag schedules to increase variability in responding in a home setting

AbstractSeveral studies have demonstrated that lag schedules can be used to increase variability in controlled settings. In this study, we replicated these procedures during regular home applied behavior analysis services using available resources with an adolescent with Autism Spectrum Disorder. The participant had learned multiple responses to questions but responded with little to no variability. The intervention included scripted prompts and lag schedules implemented across social contexts in a multiple baseline design. The scripted prompts assisted the participant in varying his responding and assisted the interventionists in monitoring and accurately implementing the lag schedule intervention. Results showed a systematic increase in varied responses across multiple social contexts, suggesting that lag schedules can be implemented with positive effects in naturalistic therapy settings.

Effects of Lag Schedules of Reinforcement on Variable Manding in Preschoolers With Disabilities

Functional communication training (FCT) is an evidence-based intervention that while often effective, can result in rote responding, reduced generalizability of target behavior, and resurgence of challenging behavior (CB) during treatment lapses. Lag schedules of reinforcement have been successfully used to address these concerns. We applied an increasing lag schedule within FCT to increase the variability and persistence of appropriate responding of four young children with disabilities while maintaining low levels of CB during treatment. Our results provide evidence regarding the effects of lag reinforcement on appropriate communication and CB during treatment and lapses in treatment with children with autism and Down syndrome. This research provides a new perspective to the field given, we assessed functional communication during baseline, assessed generalization to new contexts, and assessed social validity via both masked raters and participants’ mothers. We discuss the implications of this work and provide future directions for researcher and practice.

Increasing novel toy play actions in children with autism spectrum disorder and intellectual disabilities

ABSTRACT Children with autism spectrum disorder (ASD) can often demonstrate restricted and repetitive patterns of free play with toys, limiting their contact with the social and tangible reinforcement that is the result of more varied play. Lag schedules of reinforcement have been shown to increase novelty and variability of play actions in children with intellectual disability (ID; Baruni, R. R., Rapp, J. T., Lipe, S. L., & Novotny, M. A. (2014). Using lag schedules to increase toy play variability for children with intellectual disabilities. Behavioral interventions, 29(1), 21–35.). The current study extended the findings of Baruni et al. in three boys with ASD and ID, aged 8–10 years, in the United Arab Emirates. Novel actions increased for all participants during Lag 2 conditions following a systematic prompting strategy. Toy engagement, while variable, either increased or maintained across the intervention period. Maintenance and generalisation of behaviour change are discussed.

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.

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.

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.

A Systematic Synthesis of Lag Schedule Research in Individuals with Autism and Other Populations

Lag schedules increase operant variability. Several researchers have explored their clinical and educational applications, especially to address repetitive behavior or limited repertoires in individuals with autism spectrum disorder. In the current study, we provide the first comprehensive synthesis and appraisal of lag schedule research in humans. A multistep search strategy was employed to identify all experimental studies of lag schedules in humans published in peer-reviewed journals. We identified 38 studies that met inclusion criteria, summarized the study and participant characteristics, and evaluated evidential certainty. The results suggest that lag schedules are emerging as a promising applied behavioral technology for increasing operant variability, especially in individuals with autism spectrum disorder. We conclude with preliminary practice guidelines based on evidential certainty provided by the studies and identify future avenues of research.

Choice for reinforced behavioral variability in children with autism spectrum disorder.

Although individuals with autism spectrum disorder (ASD) tend to behave repetitively, certain reinforcement contingencies (e.g., lag schedules) can be used to increase behavioral variability. In a lag schedule, reinforcers only follow responses that differ from recent responses. The present study was designed to promote variable play behavior in preschoolers with ASD interacting with playsets and figurines and to assess preference for variability and repetition contingencies. Data have shown a preference for variability in pigeons and college students, but this effect has not been explored in clinical populations. In this experiment, preschoolers with ASD were taught to discriminate between variability and repetition contingencies. Only play behaviors that met a lag schedule were reinforced in the presence of one color, and only repetitive behaviors were reinforced in the presence of another. After differential performance was established, participants experienced a concurrent chains schedule. Participants chose between the colors taught in training and then completed a play session with the selected contingency. One participant selected variability and repetition equally. The other participants showed a slight preference for variability. These results indicate that some individuals with ASD may play repetitively, not because they prefer repetition, but because they require additional teaching to play variably.

On the Relation Between Variability and Creativity: A Summary of Early Work and Advancements from Applied Research

Creativity, or the generation of previously unobserved behavior, is a topic of interest to scientists and the general public alike. Researchers outside behavior analysis have focused on creativity as a trait of individuals. Behavior analysts, however, have focused on the variables that give rise to novel responses. Initial conceptual work examined specific environmental variables that may promote creativity. Subsequent conceptual work examined the role of the response class and the selective nature of reinforcement. As this conceptual work progressed, researchers began evaluating variables that affect response variability, a potentially critical component of variability. Most basic researchers, and some applied researchers, have focused on response sequences. Although this work has proven fruitful in understanding response variability as an operant dimension, these limited response classes have prevented a more robust understanding of variability and novelty. Following the development of the lag schedule, applied researchers began using lag schedules to increase complex behavior behavior such as responses to questions, social skills, and martial arts skills. This applied work has provided intriguing evidence that variability, and environmental influence of variability, is a key contributor to novel responding, thus bringing creativity well into our scientific understanding of behavior.

Variations of Functional Communication Training and Their Effects on Resurgence

The purpose of this study was to evaluate what effect teaching multiple functional communicative responses (FCRs) as outlined in serial functional communication training (FCT) had on resurgence of problem behavior and FCRs during extinction challenges. Researchers then evaluated what effect implementing a lag schedule of reinforcement following serial FCT had on resurgence of problem behavior and FCRs during extinction challenges compared with serial FCT. Recent findings evaluated the effect of a serial FCT procedure on resurgence of problem behavior, and the persistence of FCRs in an applied setting to determine if serial FCT would decrease the total number of responses of problem behavior during the resurgence (extinction) test while simultaneously increasing the total number FCRs as compared with the traditional (single) FCT condition for two children. They observed more manding (use of FCRs) and a smaller percentage of total responding occupied by problem behavior during serial FCT relative to traditional FCT. However, they also observed that problem behavior occupied the largest percentage of total relapse, demonstrating a primacy effect. The results of the present study indicate that teaching multiple FCRs in a serial FCT context is not sufficient to ensure the persistence of FCRs and significant delays or elimination of the resurgence of problem behavior during extinction challenges. Implementing a lag-2 schedule of reinforcement produced some desired effects, such as a higher total frequency of FCRs; however, resurgence of problem behavior was observed at higher rates and short latencies.

The Role of Recognition Memory in Learning in People with Aphasia

The Role of Recognition Memory in Learning in People with Aphasia

The Effects of Lag Schedules of Reinforcement on Social Skill Accuracy and Variability

Five participants with autism spectrum disorder (ASD) between the ages of 10 and 14 years attended a twice-weekly social skills group for 8 weeks. A multiple probe design across skills with concurrent replication across participants was utilized to assess the effects of social skills training using multiple exemplars and lag schedules on social skill variability. Prior to intervention, participants demonstrated low levels of skill accuracy and appropriate variability. Training with one and three exemplars of target skills without lag schedules resulted in no to small increases in appropriate variability, despite increases in skill accuracy. Following introduction of lag schedules, substantial increases were observed. Post-intervention rating scales completed by parents of participants indicated improvements in social functioning and reductions in repetitive behavior.

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.

An evaluation of the additive effects of lag schedules of reinforcement

ABSTRACTLag schedules of reinforcement represent an increasingly researched strategy for addressing restricted and repetitive social communication of individuals with autism spectrum disorder (ASD). Although the body of literature suggests that lag schedules of reinforcement are generally effective for this purpose, studies have varied in their utilization of verbal rules describing the contingency. Furthermore, research has yet to evaluate generalized effects of lag schedules of reinforcement to social communication with peers. This study evaluated the implementation of a social skills curriculum, modified to incorporate lag schedules of reinforcement, on novel responding of participants with ASD. Participants attended training twice per week, with probes of novel responding collected with both researchers and non-participating peers. Results indicate that social skills training that incorporated lag schedules of reinforcement generally resulted in larger increases in novel responding than social skills training alone. Furthermore, effects of training generalized to novel responding to non-participant peers.

Effects of a Lag Schedule with Progressive Time Delay on Sign Mand Variability in a Boy with Autism.

For some children with autism, mand training can produce highly repetitive manding unless the environment is arranged in a manner that promotes mand variability. Prior research demonstrated that mand training using a lag schedule and progressive time delay increased variability in vocal manding in children with autism. Whether lag schedules have similar effects on sign mand topographies is unknown. The current study evaluated the effects of mand training with a Lag 1 schedule of reinforcement and progressive time delay (TD) on topographical variability and the development of a sign mand response class hierarchy in a boy with autism. The results suggest independent use of all sign mand topographies occurred, a mand response class hierarchy was developed, and topographically variant sign manding increased under the Lag 1 + TD schedule compared to a Lag 0 schedule of reinforcement. Implications for practitioners, limitations, and directions for future research are discussed.

BMAL1 deficiency promotes skeletal mandibular hypoplasia via OPG downregulation.

Skeletal mandibular hypoplasia (SMH), a common type of developmental deformities, results in impaired aesthetics of facial profile, occlusal dysfunction and poor life quality. In this study, BMAL1 deficiency leads to SMH formation, and we aim to investigate the mechanism by which BMAL1 deficiency induces SMH. Circadian rhythm-disordered mouse models were constructed by placing animals in a jet lag schedule of 6-h light advance every 7days for 4 or 8weeks. The OPG expression was evaluated by histomorphometry, immunohistochemistry and western blot analysis. The mechanism by which BMAL1 affects OPG expression was investigated by chromatin immunoprecipitation and luciferase reporter assays. The phenotypes caused by BMAL1 knockout can be rescued by exogenous supplementation with OPG. We demonstrate that the expressions of BMAL1 and OPG decreased in SMH patients. Circadian rhythm-disordered mice and Bmal1-/- mice exhibited decreased expression of OPG, reduced bone mass and bone size of mandibles. Our results revealed that BMAL1 bound directly to the Opg promoter and upregulated its expression, thus inhibiting osteoclast differentiation. BMAL1 deficiency increased osteoclast differentiation by downregulating OPG expression. In vitro, the enhancement effect of osteoclast differentiation caused by BMAL1 knockdown was significantly reversed by exogenous supplementation with OPG. Importantly, bone loss caused by BMAL1 knockout can be partially reversed by injecting OPG Intraperitoneally. These results indicate that the circadian clock plays a critical role in the growth and development of mandible by regulating OPG expression, and present a potential therapeutic strategy to prevent SMH.

An Additive Analysis of Lag Schedules of Reinforcement and Rules on Novel Responses of Individuals with Autism Spectrum Disorder

Lag schedules of reinforcement have been found to be useful in addressing invariant behavior of individuals with autism spectrum disorder (ASD). The purpose of this study was to conduct an additive analysis of lag schedules and rules. Three participants with ASD were exposed to a Lag 2 schedule of reinforcement in isolation. Following, participants were introduced to an incomplete rule and then a complete rule regarding reinforcement in conjunction with the lag schedule. Results indicated that lag schedules in isolation were generally sufficient for increasing novel responding. The addition of incomplete and complete rules often resulted in increases, albeit small, in novel responding. Results are discussed in terms of applied use of lag schedules of reinforcement and addressing nonresponse.

Increasing Behavioral Variability and Social Skill Accuracy in Children with Autism Spectrum Disorder

Although social skills training for children with autism spectrum disorder (ASD) often addresses deficits in social communication, restricted and repetitive social behaviors are less frequently targeted in the literature. The present study evaluated a manualized social skills training program, modified to incorporate lag schedules of reinforcement, to promote appropriate and variable responding in three children in a school setting. Participants attended social skills once weekly, with probes of social skills taking place daily. A multiple baseline design across target skills was used to determine intervention efficacy. Results of the study indicated that the social skills curriculum incorporating lag schedules of reinforcement resulted in substantial increases in the number of appropriate and variable responses demonstrated by participants during each probe session, as well as the number of appropriate and variable responses demonstrated overall.

An evaluation of delay to reinforcement and mand variability during functional communication training

Children with autism spectrum disorder and other developmental disabilities often exhibit invariant responding (i.e., restricted behavioral repertoires), deficits in communication, and challenging behavior. Approaches demonstrated in the basic and applied literature to increase response variability include extinction, lag schedules of reinforcement, and percentile schedules of reinforcement. Results of basic studies have also indicated that delays to reinforcement often produce increases in response variability. The purpose of the current study was to evaluate the effects of a delay to reinforcement on the variability of communication responses during functional communication training with individuals with developmental disabilities and histories of engaging in challenging behavior. Results indicated that delays to reinforcement increased mand variability with all four participants with variable effects on challenging behavior across participants.

Persistence and relapse of reinforced behavioral variability.

The present study examined persistence and relapse of reinforced behavioral variability in pigeons. Pigeons emitted four-response sequences across two keys. Sequences produced food according to a lag schedule, in which a response sequence was followed by food if it differed from a certain number of previous sequences. In Experiment 1, food was delivered for sequences that satisfied a lag schedule in both components of a multiple schedule. When reinforcement was removed for one component (i.e., extinction), levels of behavioral variability decreased for only that component. In Experiment 2, food was delivered for sequences satisfying a lag schedule in one component of a multiple schedule. In the other component, food was delivered at the same rate, but without the lag variability requirement (i.e., yoked). Following extinction, levels of behavioral variability returned to baseline for both components after response-independent food delivery (i.e., reinstatement). In Experiment 3, one group of pigeons responded on a lag variability schedule, and the other group responded on a lag repetition schedule. For both groups, levels of behavioral variability increased when alternative reinforcement was suspended (i.e., resurgence). In each experiment, we observed some evidence for extinction-induced response variability and for variability as an operant dimension of behavior.