Sequential Associations Between Caregiver Talk and Child Play in Autism Spectrum Disorder and Typical Development.

This study examined sequential associations between child play and caregiver talk in 98 caregiver-child dyads (Mmental age  = 14 months). Fifty dyads included a child with autism spectrum disorder (ASD). Analyses revealed sequential associations between child play and caregiver follow-in (FI) utterances (utterances related to the child's attentional focus) were stronger in the ASD as compared to the typically developing (TD) group. FI utterances were more likely to elicit functional play than caregiver-focused utterances, and more so in the ASD group. Across groups, FI directives were more likely to elicit functional play than FI comments. These findings have important implications for research involving caregiver-child play as an early intervention context for children with ASD.

The relative accuracy and interpretability of five sequential analysis methods: A simulation study.

A variety of sequential analysis methods exist to quantify close temporal associations between events from direct observation data. In the present study, we compared the relative accuracy and interpretability of five sequential-analysis methods using simulated data. The methods included three existing approaches (event lag, concurrent interval, and time window) and two proposed modifications of the event lag approach (event lag with contiguous pauses and event lag with noncontiguous pauses) designed to address limitations of the existing approaches. We evaluated accuracy on the basis of the extent to which the mean contingency estimates produced by each method approximated a known mean (i.e., zero). We evaluated interpretability on the basis of the extent to which the contingency estimates produced by each method were independent from chance estimates of the two-event sequence. The results indicated that the event lag with contiguous pauses method produced the most accurate and interpretable estimates of contingency. This modified method prevents the total number of event types from influencing contingency estimates, thus solving a problem associated with the traditional event lag method.

Assessment and treatment of challenging behaviour for individuals with intellectual disability: a research review.

BACKGROUND: Challenging behaviour is frequently associated with the presence of intellectual disability. If not effectively treated, chronic challenging behaviour can negatively impact a variety of quality of life outcomes for individuals with intellectual disability. METHODS AND RESULTS: We review the current status of research relating to the assessment and treatment of challenging behaviour for people with intellectual disability. We briefly review the history of interventions for challenging behaviour that led to the development of function-based approaches widely in use today. We then discuss the various operant functions of challenging behaviour, functional behaviour assessment technologies and reinforcement-based interventions. CONCLUSIONS: We conclude with a discussion of future directions that include models of prevention, ecological validity of assessment procedures and the widespread use of comprehensive behavioural support programmes.

A Systematic Review of Direct Assessments to Evaluate Psychotropic Medication Effects for Children With Disabilities.

To evaluate effects of psychotropic medication for children with disabilities, direct assessments may offer a valuable supplement to caregiver reports. Relative to indirect assessment, direct measures of behavior can increase objectivity and sensitivity, and some have potential to isolate distinct behavioral and learning processes. We conducted a systematic, narrative literature review to identify and describe the types and qualities of direct assessment methods that have been used to evaluate effects of non-stimulant psychotropic medication for children with disabilities. We identified 50 studies and 78 direct assessments, which we organized and described using seven assessment categories. Only one study met all three direct assessment quality indicators. We use our descriptive results to highlight research trends and gaps that warrant further study.

Direct Measures of Medication Effects: Exploring the Scientific Utility of Behavior-Analytic Assessments.

The purpose of the current study was to explore the scientific utility of two behavior analytic assessments (i.e., progressive ratio and demand assessments) for psychotropic medication evaluation. For a sample of 23 children with disabilities who were prescribed medication, we conducted a series of generalizability and optimization studies to identify sources of score variance and conditions in which stable estimates of behavior can be obtained. To inform construct validity, we calculated correlations between scores from each assessment and those from a standardized behavior rating scale (Aberrant Behavior Checklist-Second Edition; ABC-2). Results offer initial support for the scientific utility of progressive ratio scores. More research is needed to evaluate sensitivity to change and construct validity of scores from these and other behavior analytic assessments.

Effects of self-control training for elementary students with emotional and behavioral disorders.

Progressive delay training (PDT) has been used to promote self-controlled choices (i.e., selecting a larger, later reward over a smaller, immediate reward) for people with a variety of developmental characteristics. However, the efficacy of PDT has not been evaluated in children with emotional and behavioral disorders (EBD), who often have co-occurring symptoms of impulsivity. The purpose of this study was to evaluate the effects of PDT with a rule-following requirement on the impulsive choices of 6 elementary students with EBD using a modified changing criterion design. Results indicated that PDT alone did not improve self-control, but a modified version of PDT with a rationale and rule for selecting the delayed reward promoted self-control for 3 participants. The remaining 3 participants continued to make impulsive choices despite further modifications to the PDT protocol. We discuss implications of our results and directions for future research on treating impulsivity in children with EBD.

Randomization Tests for Single Case Designs with Rapidly Alternating Conditions: An Analysis of p-Values from Published Experiments.

Two common barriers to applying statistical tests to single-case experiments are that single-case data often violate the assumptions of parametric tests and that random assignment is inconsistent with the logic of single-case design. However, in the case of randomization tests applied to single-case experiments with rapidly alternating conditions, neither the statistical assumptions nor the logic of the designs are violated. To examine the utility of randomization tests for single-case data, we collected a sample of published articles including alternating treatments or multielement designs with random or semi-random condition sequences. We extracted data from graphs and used randomization tests to estimate the probability of obtaining results at least as extreme as the results in the experiment by chance alone (i.e., p-value). We compared the distribution of p-values from experimental comparisons that did and did not indicate a functional relation based on visual analysis and evaluated agreement between visual and statistical analysis at several levels of α. Results showed different means, shapes, and spreads for the p-value distributions and substantial agreement between visual and statistical analysis when α = .05, with lower agreement when α was adjusted to preserve family-wise error at .05. Questions remain, however, on the appropriate application and interpretation of randomization tests for single-case designs.

Effects of School-Home Communication With Parent-Implemented Reinforcement on Off-Task Behavior for Students With ASD.

School-home communication is highly valued for parents of students with autism spectrum disorders (ASD) and other developmental disabilities. However, parents report poor communication as a common barrier to developing partnerships with schools. Using a multiple baseline design, we evaluated the effects of a school-home note intervention with parent-implemented reinforcement for decreasing off-task behavior of students with ASD at school. We also evaluated social validity (i.e., feasibility and acceptability) of the intervention and outcomes. Only two of the four participants showed clear behavior change, which precluded the demonstration of functional relations. However, all participating parents and teachers reported the school-home note and parent-implemented contingent reinforcement were highly feasible and acceptable, and indicated positive outcomes relating to improved family-school partnership and communication. Findings of this study, which meets single-case design standards and quality indicators, are discussed in terms of future research and practice.

Experimental analysis of stereotypy with applications of nonparametric statistical tests for alternating treatments designs.

INTRODUCTION: Stereotypy is common in individuals with developmental disabilities and may become disruptive in the context of instruction. PURPOSE: The purpose of this study was to embed brief experimental analyses in the context of reading instruction to evaluate effects of antecedent and consequent variables on latencies to and durations of stereotypy. METHOD: We trained a reading instructor to implement a trial-based functional analysis and a subsequent antecedent analysis of stimulus features for an adolescent with autism in a reading clinic. We used alternating treatments designs with applications of nonparametric statistical analyses to control Type I error rates. RESULTS: Results of the experimental analyses suggested stereotypy was maintained by non-social reinforcement and informed the extent to which features of academic materials influenced levels of stereotypy. Results of nonparametric statistical analyses were consistent with conclusions based on visual analysis. CONCLUSION: Brief experimental analyses may be embedded in academic instruction to inform the stimulus conditions that influence stereotypy.

A comparison of analysis methods to estimate contingency strength.

To date, several data analysis methods have been used to estimate contingency strength, yet few studies have compared these methods directly. To compare the relative precision and sensitivity of four analysis methods (i.e., exhaustive event-based, nonexhaustive event-based, concurrent interval, concurrent+lag interval), we applied all methods to a simulated data set in which several response-dependent and response-independent schedules of reinforcement were programmed. We evaluated the degree to which contingency strength estimates produced from each method (a) corresponded with expected values for response-dependent schedules and (b) showed sensitivity to parametric manipulations of response-independent reinforcement. Results indicated both event-based methods produced contingency strength estimates that aligned with expected values for response-dependent schedules, but differed in sensitivity to response-independent reinforcement. The precision of interval-based methods varied by analysis method (concurrent vs. concurrent+lag) and schedule type (continuous vs. partial), and showed similar sensitivities to response-independent reinforcement. Recommendations and considerations for measuring contingencies are identified.

Single-case synthesis tools I: Comparing tools to evaluate SCD quality and rigor.

Tools for evaluating the quality and rigor of single case research designs (SCD) are often used when conducting SCD syntheses. Preferred components include evaluations of design features related to the internal validity of SCD to obtain quality and/or rigor ratings. Three tools for evaluating the quality and rigor of SCD (Council for Exceptional Children, What Works Clearinghouse, and Single-Case Analysis and Design Framework) were compared to determine if conclusions regarding the effectiveness of antecedent sensory-based interventions for young children changed based on choice of quality evaluation tool. Evaluation of SCD quality differed across tools, suggesting selection of quality evaluation tools impacts evaluation findings. Suggestions for selecting an appropriate quality and rigor assessment tool are provided and across-tool conclusions are drawn regarding the quality and rigor of studies. Finally, authors provide guidance for using quality evaluations in conjunction with outcome analyses when conducting syntheses of interventions evaluated in the context of SCD.

Single-case synthesis tools II: Comparing quantitative outcome measures.

Varying methods for evaluating the outcomes of single case research designs (SCD) are currently used in reviews and meta-analyses of interventions. Quantitative effect size measures are often presented alongside visual analysis conclusions. Six measures across two classes-overlap measures (percentage non-overlapping data, improvement rate difference, and Tau) and parametric within-case effect sizes (standardized mean difference and log response ratio [increasing and decreasing])-were compared to determine if choice of synthesis method within and across classes impacts conclusions regarding effectiveness. The effectiveness of sensory-based interventions (SBI), a commonly used class of treatments for young children, was evaluated. Separately from evaluations of rigor and quality, authors evaluated behavior change between baseline and SBI conditions. SBI were unlikely to result in positive behavior change across all measures except IRD. However, subgroup analyses resulted in variable conclusions, indicating that the choice of measures for SCD meta-analyses can impact conclusions. Suggestions for using the log response ratio in SCD meta-analyses and considerations for understanding variability in SCD meta-analysis conclusions are discussed.

Quantifying contingent relations from direct observation data: transitional probability comparisons versus Yule's Q.

Measuring contingencies or sequential associations may be applied to a broad range of response-stimulus, stimulus-stimulus, or response-response relations. Within behavior analysis, response-stimulus contingencies have been quantified by comparing 2 transitional probabilities and plotting them in contingency space. Within and outside behavior analysis, Yule's Q has become a recommended statistic used to quantify sequential associations between 2 events. In the current paper, we identify 2 methods of transitional probability comparisons used in the behavior-analytic literature to estimate contingencies in natural settings. We compare each of these methods to the more established Yule's Q statistic and evaluate relations between each pair of indices. Advantages and disadvantages of each method are identified, with recommendations as to which approach may be most appropriate for measuring contingencies.

Serotonin2A/C receptors mediate the aggressive phenotype of TLX gene knockout mice.

Deleting the tailless (TLX) gene in mice produces a highly aggressive phenotype yet to be characterized in terms of heterozygous animals or neurotransmitter mechanisms. We sought to establish pharmacological control over aggression and study the role of serotonin (5-HT)(2A/C) receptors in mediating changes in aggression. We analyzed aggression in mice heterozygous (+/-) or homozygous (-/-) for the TLX gene and wild-types (+/+) using a resident-intruder paradigm. No +/+ mice were aggressive, 36% of +/- TLX and 100% of -/- TLX mice showed aggression. Dose-effect functions were established for clozapine (0.1-1.5mg/kg, ip), ketanserin (0.3-1.25 mg/kg, ip), and (±)-1-(2,5-dimethoxy-4-iodophenyl)-2-aminopropane [(±)DOI] (0.5-2.0 mg/kg, ip). Injecting clozapine decreased the frequency and duration of attacks for +/- TLX and -/- TLX mice. Clozapine did not decrease grooming in either +/- TLX or -/- TLX mice but may have increased locomotion for -/- TLX mice. Injecting ketanserin, a 5-HT(2A/C) receptor antagonist, produced differential decreases in frequency and latency to aggression between genotypes and corresponding increases in locomotor behavior. Injecting (±)DOI, a 5-HT(2A/C) receptor agonist, increased the frequency and duration of attacks, decreased the latency to attacks, and decreased locomotion in +/- and -/- TLX mice. Results of the current study suggest aggression displayed by TLX null and heterozygous mice involves 5-HT(2A/C) receptors.