Discrete Trial Research Articles

Notes on a saddle point reformulation of mixed variational problems

We summarize some general ideas regarding approximation of mixed variational problems using saddle point reformulation. We consider the concepts of optimal and almost optimal (or α) test norm and provide estimates for the continuity and stability constants. A preconditioning strategy for solving the discrete mixed formulations is used in combination with the special test norms. We further provide a choice for a discrete trial space, that depends on the choice of a standard test space and leads to discrete stability, when using the appropriate test norm. Examples to illustrate how the stability of the saddle point discretization can be improved using special test norms are included.

"Errorless" Toilet Training: "The Potty Party"

The current study describes the use of a procedure called the party, an all-day toilet training method using basic learning principles of “errorless” discrimination with 3 children with incontinence diagnosed with autism. At the start of treatment days, each participant was greeted and prompted to request the bathroom. After the child requested the bathroom, they were taken to the restroom, pants and underpants were removed, the child was seated on the toilet. While on-seat, participants were given liquids, less-preferred reinforcers and engaged in typical daily activities such as discrete trial training. When the child voided in the toilet, specific verbal praise and highly preferred edible reinforcers were delivered. The child was also given time off the toilet with their most preferred toys or items/activities. Time off-toilet subsequently increased with each in-toilet urination until the participants were spending the same amount of time off-toilet, out-of-bathroom, and in the classroom as their peers. Results for all three participants using 3 non-concurrent A-B phase designs indicated that the potty party procedure was effective in decreasing accidents to zero levels for all three participants and increased in-toilet urination for two. Future directions for research in toileting are discussed.

Research on Technological Interventions for Young Children with Autism Spectrum Disorders: a Scoping Review

Researchers have widely reported using technological interventions to support young children with autism spectrum disorder. Given the abundance and diversity of research on the topic, the authors conducted a scoping review of 158 studies published from 1994 to 2019 to provide a current state of the literature and guide future research. Overall, the results indicate that video modeling, communication aids, and discrete trial instruction have been the topic of the most studies in the research literature. Moreover, most researchers have used single-case designs and combined technology with some type of adult provided support. Findings suggest that future studies should compare the use of different devices and interventions directly together while better isolating the unique contribution of technology when evaluating its effects.

A large scale analysis of the impact of trial type and instructional errors on acquisition during discrete trial training

Discrete trial training is one evidence-based instructional procedure within Applied Behavior Analysis. Two important considerations when using this procedure are trial presentation type and treatment integrity. Research has demonstrated both these considerations affect skill acquisition for children with developmental disabilities but has not rigorously examined their independent and interactive impact on learning in larger samples. The present study is a translational approach to better understand learning during discrete trial training. Specifically, we compared trial presentation type (varied instruction versus task interspersal) on skill acquisition during high- and low-treatment integrity conditions in 166 college students. Findings demonstrated task interspersal resulted in better acquisition and maintenance than varied instruction and that low treatment integrity significantly impaired learning. No interaction between trial presentation type and treatment integrity emerged. Discussion of learning processes and implications for instruction is included in light of present findings.

Habitual Preference for the Nondrug Reward in a Drug Choice Setting.

For adaptive and efficient decision making, it must be possible to select between habitual alternative courses of action. However, research in rodents suggests that, even in the context of simple decision-making, choice behavior remains goal-directed. In contrast, we recently found that during discrete trial choice between cocaine and water, water-restricted rats preferred water and this preference was habitual and inflexible (i.e., resistant to water devaluation by satiation). Here we sought to test the reproducibility and generality of this surprising finding by assessing habitual control of preference for saccharin over cocaine in non-restricted rats. Specifically, after the acquisition of preference for saccharin, saccharin was devalued and concurrent responding for both options was measured under extinction. As expected, rats responded more for saccharin than for cocaine during extinction, but this difference was unaffected by saccharin devaluation. Together with our previous research, this result indicates that preference for nondrug alternatives over cocaine is under habitual control, even under conditions that normally support goal-directed control of choice between nondrug options. The possible reasons for this difference are discussed.

Efficacy of Interventions Based on Applied Behavior Analysis for Autism Spectrum Disorder: A Meta-Analysis.

ObjectiveTo systematically evaluate evidence for the use of interventions based on appied behavior analysis (ABA) to manage various symptoms of children with autism spectrum disorder (ASD). MethodsSensitivity analyses were conducted by removing any outlying studies and subgroup analyses were performed to compare the effectiveness of ABA and early start denver model (ESDM), picture exchange communication systems (PECS) and discrete trial training (DTT). Results14 randomized control trials of 555 participants were included in this meta-analysis. The overall standardized mean difference was d=-0.36 (95% CI -1.31, 0.58; Z=0.75, p=0.45) for autism general symptoms, d=0.11 (95% CI -0.31, 0.54; Z=0.52, p=0.60) for socialization, d=0.30 (95% CI -0.02, 0.61; Z=1.84, p=0.07) for communication and d=-3.52 (95% CI -6.31, -0.72; Z=2.47, p=0.01) for expressive language, d=-0.04 (95% CI -0.44, 0.36; Z=0.20, p=0.84) for receptive language. Those results suggested outcomes of socialization, communication and expressive language may be promising targets for ABA-based interventions involving children with ASD. However, significant effects for the outcomes of autism general symptoms, receptive language, adaptive behavior, daily living skills, IQ, verbal IQ, nenverbal IQ, restricted and repetitive behavior, motor and cognition were not observed. ConclusionThe small number of studies included in the present study limited the ability to make inferences when comparing ABA, ESDM, PECS and DTT interventions for children with ASD.

Transitioning from rich to lean reinforcement as a form of error correction.

Discrete trial instruction (DTI) is a ubiquitous tool used by practitioners in early intervention programs. A common approach to correcting errors during DTI involves providing a single prompt of the target response when a mistake is made (i.e., single-response repetition). Modifications to the single-response repetition approach have been developed to improve acquisition; however, these modifications are often aversive techniques (e.g., increased effort, response cost) and may not be preferred by the children or considered socially acceptable by caregivers. We conducted this study to evaluate the use of a transition from rich to lean reinforcement as a form of error correction. We compared the rich-lean condition to the single-response repetition approach during DTI for 4 boys diagnosed with autism. The rich-lean condition was (a) more efficient in improving accuracy in 6 out of 9 tasks, (b) more preferred by all participants, and (c) socially validated by caregivers.

Thinking in Pictures Educational Services (TIPES): A Preliminary Report of an Intensive Behavioral Intervention for Children with Moderate to Severe Autism Spectrum Disorder

Introduction: Autism spectrum disorder (ASD) is a potentially severely disabling exceptionality, and there is evidence of increasing incidence. In extreme cases major challenges can develop early in childhood for those individuals, their families and educational services. Social isolation, language problems, sensory and behavioural problems can all become entrenched if effective support is not provided. Interventions capable of delivering a recovery trajectory with transition to public/private education for children with moderate to severe ASD have been infrequently reported in the literature. Intensive behavioural intervention (IBI) as delivered within the Thinking in Pictures Educational Services (TIPES) has, as yet, not been tested as an intervention for children with moderate to severe autism. Methodology: IBI was delivered over a minimum of 12 months with 25-40 hours of individual therapy per week. Following a baseline memory paradigm assessment, a participant-specific IBI intervention was delivered. A combination of discrete trial training and ESDM, verbal behavior approach followed by direct instruction programs were used to improve language and social functioning. Baseline and end of intervention Assessment of Basic Language and Learning Skills-Revised (ABLLS-R) scores were recorded and compared to standard age adjusted mean childhood scores for educational ability. Each participant was assessed Assessment of Autism Treatment Evaluation Checklist (ATEC) in order to evaluate the impact of the intervention on the 4 domains of ASD (speech, sociability, sensory, behaviour performance). The primary end point was taken as the last score on the ATEC and ABLLS-R. The primary outcome was attendance in public and privately funded classroom settings. Results: All results within this study were significant. In terms of the primary outcome 9 out of 14 children with moderate to severe childhood ASD treated with IBI, using the TIPES method attended public/private funded sector education during the second year. There was an effect size (number needed to treat) of 2 indicating a very effective intervention. Basic language and learning skills as scored on the ABLLS-R significantly improved (p<0.000). Core characteristics of ASD as measured on the ATEC total scores significantly improved at end of treatment (p<0.012). All ATEC subscale scores significantly improved. Baseline mean speech scores significantly improved (p<0.006) as did sociability (p<0.005), sensory (p<0.078) and behaviour scores (p<0.041). Conclusion: This preliminary study indicated that educational attendance was possible for the majority of children with moderate to severe ASD who were accepted by TIPES and treated with an individualised combined IBI approach based on memory and learning capacity. If these results can be replicated this would be a highly cost-effective intervention.

The influence of instructive feedback presentation schedule: A replication with children with autism spectrum disorder.

Instructive feedback (IF) is a modification to discrete trial instruction that may increase instructional efficiency for individuals with autism spectrum disorder. Several variations of IF have recently been evaluated in the literature; however, few studies have assessed the effectiveness and efficiency of presenting secondary targets on continuous versus intermittent presentation schedules. The current study evaluated the effectiveness and efficiency of various presentation schedules of secondary targets during discrete trial instruction. Specifically, we replicated and extended Griffen et al. (1998) by comparing a condition in which secondary targets were presented during each trial of a session, a condition in which secondary targets were presented every other trial, and a condition in which secondary targets were presented about every 4 trials. Within-subject replications were included for both participants. One of the intermittent presentation schedules was associated with the most optimal outcomes in all 4 comparisons.

Investigating the Efficacy of Discrete Trial Training Program in the Development of Sustained Eye Contact in an Adolescent Girl with Autism Spectrum Disorder: A Case Study

Investigating the Efficacy of Discrete Trial Training Program in the Development of Sustained Eye Contact in an Adolescent Girl with Autism Spectrum Disorder: A Case Study

Effects of Remote Performance Feedback on Procedural Integrity of Early Intensive Behavioral Intervention Programs in China

In order to ensure the effects of early intensive behavioral interventions for children with autism, performance feedback is often used to improve procedural integrity. However, in areas where access to professionals is limited, onsite feedback may not be feasible. Researchers suggest that providing remote feedback may improve procedural integrity, but they often examined feedback along with other components. Thus, the purpose of this study is to investigate the effects of remote feedback alone on improving procedural integrity of discrete trial teaching (DTT) and incidental teaching (IT) of three interventionists in China. The interventionists received delayed remote feedback on either DTT or IT via video communication. Using an alternating treatment design, we directly compared the procedural integrity under the two conditions: with and without delayed remote feedback. Results showed that all interventionists improved procedural integrity only after feedback was introduced, suggesting that delayed remote feedback alone was effective in improving procedural integrity. The discussion addresses the practical and research implications of the findings.

Empirically based developmental and behavioral intervention programs targeting the core symptoms and language development in toddlers and preschool children with autism spectrum disorder

Empirically based developmental and behavioral intervention programs targeting the core symptoms and language development in toddlers and preschool children with autism spectrum disorder Abstract. This systematic review summarizes findings of articles included in the German AWMF-S3 clinical guideline on early intervention in autism spectrum disorders (ASD). We present the current state-of the art of evidence-based interventions for toddlers and preschool-aged children with ASD, specifically targeting the core symptoms and language development. We included studies on manualized developmental and behavioral interventions for children with ASD aged <7 years according to DSM-III(R), DSM-IV(TR), DSM-5, and ICD-10. The publication dates ranged from 1 January 2011 to 31 August 2018 or as included in the NICE-children guidelines. Studies were included by an iterative hierarchy: systematic review > randomized-controlled trial > clinically controlled trial. Outcome measures were core ASD symptoms and precursor abilities, or language abilities. The interventions were collated by (1) frequency and (2) approach. The studies focused on low-intensive interventions targeting parental synchrony, the child's initiations, reciprocity, joint attention, play and imitation skills as well as comprehensive interventions. Improvement of core ASD symptoms regarding social communication was observed for low-intensive training of parental synchrony and child's reciprocity as well as for low-intensive comprehensive developmental interventions implementing natural-learning paradigms. High-frequency discrete trial interventions did not improve social communication. Language abilities improved by comprehensive interventions. In conclusion, intervention recommendations are summarized.

How accurate are autistic adults and those high in autistic traits at making face-to-face line-of-sight judgements?

Being able to follow the direction of another person’s line-of-sight facilitates social communication. To date, much research on the processes involved in social communication has been conducted using computer-based tasks that lack ecological validity. The current paradigm assesses how accurately participants can follow a social partner’s line-of-sight in a face-to-face scenario. In Study 1, autistic and neurotypical adults were asked to identify which location, on a grid of 36 potential locations, the experimenter was looking at on a series of discrete trials. All participants (both autistic and neurotypical) were able to effectively make line-of-sight judgements, scoring significantly above chance. Participants were also just as effective at making these judgements from either a brief, 1s, glance or from a prolonged, 5s, stare. However, at the group level, autistic participants were significantly less accurate than neurotypical participants overall. In Study 2, potential variation in performance along the broad autism phenotype was considered using the same paradigm. Bayesian analyses demonstrated that line-of-sight judgement accuracy was not related to the amount of autistic traits. Overall, these findings advance the understanding of the mechanistic processes of social communication in relation to autism and autistic traits in a face-to-face setting.Lay abstractIn order to effectively understand and consider what others are talking about, we sometimes need to follow their line-of-sight to the location at which they are looking, as this can provide important contextual information regarding what they are saying. If we are not able to follow other people’s line-of-sight, this could result in social communication difficulties. Here we tested how effectively autistic and neurotypical adults are at following a social partner’s line-of-sight during a face-to-face task. In a first study, completed by 14 autistic adult participants of average to above-average verbal ability and 14 neurotypical adult participants, we found that all participants were able to effectively follow the social partner’s line-of-sight. We also found that participants tended to be as effective at making these judgements from both a brief, 1s, glance or a long, 5s, stare. However, autistic adults were less accurate, on average, than neurotypical adults overall. In a second study, a separate group of 65 neurotypical adults completed the same line-of-sight judgement task to investigate whether task performance was related to individual variation in self-reported autistic traits. This found that the amount of self-reported autistic traits was not at all related to people’s ability to accurately make line-of-sight judgements. This research isolates and furthers our understanding of an important component part of the social communication process and assesses it in a real-world context.

Neural Circuit Dynamics for Sensory Detection.

We consider the question of how sensory networks enable the detection of sensory stimuli in a combinatorial coding space. We are specifically interested in the olfactory system, wherein recent experimental studies have reported the existence of rich, enigmatic response patterns associated with stimulus onset and offset. This study aims to identify the functional relevance of such response patterns (i.e., what benefits does such neural activity provide in the context of detecting stimuli in a natural environment). We study this problem through the lens of normative, optimization-based modeling. Here, we define the notion of a low-dimensional latent representation of stimulus identity, which is generated through action of the sensory network. The objective of our optimization framework is to ensure high-fidelity tracking of a nominal representation in this latent space in an energy-efficient manner. It turns out that the optimal motifs emerging from this framework possess morphologic similarity with prototypical onset and offset responses observed in vivo in locusts (Schistocerca americana) of either sex. Furthermore, this objective can be exactly achieved by a network with reciprocal excitatory-inhibitory competitive dynamics, similar to interactions between projection neurons and local neurons in the early olfactory system of insects. The derived model also makes several predictions regarding maintenance of robust latent representations in the presence of confounding background information and trade-offs between the energy of sensory activity and resultant behavioral measures such as speed and accuracy of stimulus detection.SIGNIFICANCE STATEMENT A key area of study in olfactory coding involves understanding the transformation from high-dimensional sensory stimulus to low-dimensional decoded representation. Here, we examine not only the dimensionality reduction of this mapping but also its temporal dynamics, with specific focus on stimuli that are temporally continuous. Through optimization-based synthesis, we examine how sensory networks can track representations without prior assumption of discrete trial structure. We show that such tracking can be achieved by canonical network architectures and dynamics, and that the resulting responses resemble observations from neurons in the insect olfactory system. Thus, our results provide hypotheses regarding the functional role of olfactory circuit activity at both single neuronal and population scales.

How long is the interval over which trial-to-trial effects on Fitts' Law task can operate?

Fitts' Law is a well-studied principle in psychology which holds that movement time (MT) varies with the size and distance of a target across a wide range of tasks. In a recent study, the authors demonstrated that performance on a current trial in a Fitts' Law paradigm is affected by what happens during the previous trial (Tang et al. in Psychon Bull Rev 25(5):1833-1839, 2018). The aim of the present study was to explore how long this trial-to-trial transfer might last and whether or not the transfer would occur between the left and right hands. A series of experiments was carried out using discrete trials, a paradigm in which the current authors and others have previously established that Fitts' Law operates (Fitts and Peterson in J Exp Psychol 67(2):103-112, 1964; Tang et al. 2018). Three inter-trial intervals (3s, 4s, and 5s) were used in separate testing sessions, the order of which was counterbalanced across participants. In addition, trial-to-trial transfer was tested within a single hand and between hands. The results demonstrate that transfer from one trial to the next could bridge 4s when either the right or the left hand was used and would disappear by 5s. Moreover, the effect transferred between the two hands. The endpoint accuracy of the current trial was not affected by the previous trial. These findings suggest that the trial-to-trial effect reduces over time and that the transfer of sensorimotor memory or the task set is independent of the particular hand used.

Ventral hippocampus inactivation enhances the extinction of active avoidance responses in the presence of safety signals but leaves discrete trial operant active avoidance performance intact.

The acquisition of active avoidance (AA) behavior is typically aided by the presence of two signals-the warning signal, which predicts the future occurrence of an aversive event (e.g., shocks), and the safety signal, which is presented upon successful avoidance of oncoming shocks. While the warning signal could be conceived to act as a Pavlovian fear cue, and is likely mediated by brain areas that underlie Pavlovian fear cue conditioning, the neural substrates underlying safety signaling are less clear, largely due to the unavailability of AA tasks that are devoid of an explicit warning signal. The present study sought to investigate the role of the ventral hippocampus (VH) in safety signaled AA performance acquired without an explicit warning signal, using a novel discrete trial paradigm. Adult male Long Evans rats were divided into two groups and trained to acquire AA responses with, or without a safety signal. Analysis of the acquisition and stable state performance data revealed that the availability of a safety signal alone did not improve the acquisition or performance of AA responses. Furthermore, post-training, reversible VH inactivation did not impact stable state avoidance behavior. However, extinction of avoidance responses was facilitated in the group trained with a safety signal, and this effect was further potentiated by VH inactivation. Additional elevated plus maze (EPM), light-dark box, and locomotor tests demonstrated that VH inactivation reduced anxiety without affecting locomotor activity. Taken together, these results demonstrate the importance of VH in the extinction of persistent pathological avoidance behavior when safety is signaled.

Effectively Integrating Direct Instruction and Discrete Trial Training Across Routines, Activities, and Environments

With young children, there is often an instructional focus on naturalistic interactions between the child and environment. In special education, there are times when direct instruction (di) and discrete trial training (DTT) are both needed, requiring a balance of explicit DTT and child-initiated instruction. This article discusses what individually and developmentally appropriate di and DTT practice and real-life examples look and sound like, and explains how to embed them across routines, activities, and environments.

An evaluation of estimation data collection to trial‐by trial data collection during discrete trial teaching

There are many data collection procedures used during discrete trial teaching including first‐trial data collection, probe data, trial‐by‐trial data collection, and estimation data. Continuous, or trial‐by‐trial data collection, consists of the interventionist collecting data on learner behavior on each trial. Estimation data consists of the interventionist estimating learner performance after a teaching session using a rating scale. The purpose of the present study was to compare trial‐by‐trial data collection to estimation data collection during discrete trial teaching to teach children expressive labels. The data collection procedures were examined in terms of accuracy of data collection, efficiency of teaching (i.e., number of trials delivered per session), and rate of child acquisition of targets. Results of the adapted alternating treatment design replicated across three participants and multiple targets found estimation data collection to be as accurate as trial‐by‐trial data collection in determining mastery of targets. Estimation data collected by the interventionist was also found to be accurate when compared to the actual trial‐by‐trial data collected after the study concluded.

Increased cognitive load during acquisition of a continuous task eliminates the learning effects of self-controlled knowledge of results

ABSTRACTPrevious research has demonstrated that providing learners with self-control over some aspect of practice enhances motor learning (for a review see Wulf, 2007). One explanation for the self-control effect is that learners engage in deeper information processing when they are allowed to make choices during practice. Recent research has supported this line of thinking by showing that the self-control effect was eliminated for learners who engaged in a cognitive load task during the interval following completion of discrete task trials (Carter & Ste-Marie, 2017). The current study tested the effects of imposing a cognitive load task during the completion of continuous task trials. Participants (N = 48) were divided into self-control (SC), self-control with load (SCL), and two corresponding yoked (YK, YKL) groups. Participants learned a continuous tracing task and then performed 24-hour retention and transfer tests. Retention and transfer test movement times were significantly faster for SC compared to YK participants within the No Load condition but did not differ between these participants within the Load condition. Errors were similar among all groups in retention and transfer. These results provide support for the importance of information processing in regards to the self-controlled learning benefit.

Systematic Review of Matrix Training for Individuals With Autism Spectrum Disorder

Matrix training is an intervention that systematically programs for the occurrence of generative outcomes, mostly in the area of language. A literature search identified studies that evaluated matrix training with individuals with autism spectrum disorder (ASD). Based on 12 reviewed studies, we asked questions regarding participant characteristics, targeted skills, matrix designs, evidence-based teaching strategies, percentage of learning that occurred through direct teaching and recombinative generalization, and the quality of the studies. With 29 total participants, mostly preschool and elementary ages, the most common teaching strategy implemented was a discrete trial training paradigm targeting language development. Overall, findings suggest that matrix training produced an average of 69% of learning without direct teaching across the areas of language, play, sentence construction, and spelling.