The Role of Contingencies and Stimuli in a Human Laboratory Model of Treatment of Problem Behavior.

Behavioral momentum theory posits a paradoxical implication for behavioral interventions in clinical situations using Differential Reinforcement of Alternative Behavior (DRA): When alternative reinforcers are presented within the same context as the problem behavior, the added reinforcers may decrease the frequency of the behavior but also increase its persistence when the intervention ends. Providing alternative reinforcers in a setting that is distinctively different from that in which the target behavior occurs may avoid or reduce this increase in persistence. The present experiment compared behavioral persistence following standard DRA versus DRA in a different context that was available after refraining from target behavior (Differential Reinforcement of Other Behavior, DRO). We arranged a human laboratory model of treatment intervention using computer games and token reinforcement. Participants were five individuals with intellectual disabilities. Experimental phases included (a) an initial multiple-schedule baseline with token reinforcement for target behaviors A and B, (b) an intervention phase with alternative reinforcement using a conventional DRA procedure for A and a DRO-DRA procedure for B, and (c) an extinction phase with no interventions and no tokens. Response rates as proportion of baseline in the initial extinction phase were greater for A than for B for three of five participants. Four participants whose response rates remained relatively high during the extinction phase then received a second extinction-plus-distraction test with leisure items available. Response rates were greater for A than for B in three of four participants. The results indicate that DRO-DRA contingencies may contribute to reduced post-intervention persistence of problem behavior.

Reducing overselective stimulus control with differential observing responses.

Overselective stimulus control refers to discriminative control in which the number of controlling stimuli is too limited for effective behavior. Experiment 1 included 22 special-education students who exhibited overselective stimulus control on a two-sample delayed matching task. An intervention added a compound identity matching opportunity within the sample observation period of the matching trials. The compound matching functioned as a differential observing response (DOR) in that high accuracy verified observation and discrimination of both sample stimuli. Nineteen participants learned to perform the DOR and two-sample delayed matching accuracy increased substantially for 16 of them. When the DOR was completely withdrawn after 10 sessions, accuracy declined. In Experiment 2, a more gradual withdrawal of DOR requirements showed that highly accurate performance could be maintained with the DOR on only a proportion of trials for most participants. The results show that DOR training may lead to a general improvement in observing behavior.

Stimulus Overselectivity in Autism, Down Syndrome, and Typical Development.

Stimulus overselectivity refers to maladaptive narrow attending that is a common learning problem among children with intellectual disabilities and frequently associated with autism. The present study contrasted overselectivity among groups of children with autism, Down syndrome, and typical development. The groups with autism and Down syndrome were matched for intellectual level, and all three groups were matched for developmental levels on tests of nonverbal reasoning and receptive vocabulary. Delayed matching-to-sample tests presented color/form compounds, printed words, photographs of faces, Mayer-Johnson Picture Communication Symbols, and unfamiliar black forms. No significant differences among groups emerged for test accuracy scores. Overselectivity was not statistically overrepresented among individuals with autism in contrast to those with Down syndrome or typically developing children.

A sorting-to-matching method to teach compound matching to sample.

Individuals with developmental disabilities may fail to attend to multiple features in compound stimuli (e.g., arrays of pictures, letters within words) with detrimental effects on learning. Participants were 5 children with autism spectrum disorder who had low to intermediate accuracy scores (35% to 84%) on a computer-presented compound matching task. Sample stimuli were pairs of icons (e.g., chair-tree), the correct comparison was identical to the sample, and each incorrect comparison had one icon in common with the sample (e.g., chair-sun, airplane-tree). A 5-step tabletop sorting-to-matching training procedure was used to teach compound matching. The first step was sorting 3 single pictures; subsequent steps gradually changed the task to compound matching. If progress stalled, tasks were modified temporarily to prompt observing behavior. After tabletop training, participants were retested on the compound matching task; accuracy improved to at least 95% for all children. This procedure illustrates one way to improve attending to multiple features of compound stimuli.

A statewide survey assessing practitioners' use and perceived utility of functional assessment.

The field of applied behavior analysis emphasizes the importance of conducting functional assessment before treatment development for problem behavior. There is, however, little information regarding the extent to which practitioners are using functional assessment in applied settings for individuals with developmental disabilities (DD). The purpose of the current study was to conduct a survey to assess the degree to which various types of functional assessment are implemented in agencies that serve individuals with DD in Massachusetts. Practitioners were asked to indicate their perception about and use of the various categories of functional assessment (e.g., indirect assessment, descriptive assessment, and functional analysis). From the 205 respondents who completed the survey, the most frequently used functional assessment was descriptive assessment. Results indicated that although the majority (67.8%) of practitioners believe functional analysis to be the most informative assessment tool for selecting behavioral treatment, only 34.6% of respondents indicated that they typically use functional analysis to inform the development of a behavior plan.

Functional analysis of problem behavior: A systematic approach for identifying idiosyncratic variables.

When inconclusive functional analysis (FA) outcomes occur, a number of modifications have been made to enhance the putative establishing operation or consequence associated with behavioral maintenance. However, a systematic method for identifying relevant events to test during modified FAs has not been evaluated. The purpose of this study was to develop and evaluate a technology for systematically identifying events to test in a modified FA after an initial FA led to inconclusive outcomes. Six individuals, whose initial FA showed little or no responding or high levels only in the control condition, participated. An indirect assessment (IA) questionnaire developed for identifying idiosyncratic variables was administered, and a descriptive analysis (DA) was conducted. Results from the IA only or a combination of the IA and DA were used to inform modified FA test and control conditions. Conclusive FA outcomes were obtained with 5 of the 6 participants during the modified FA phase.

Stimulus Fading and Response Elaboration in Differential Reinforcement for Alternative Behavior.

A hallmark of applied behavior analysis is the development of function-based interventions for problem behavior. A widely recommended function-based intervention is differential reinforcement of alternative behavior (DRA), in which reinforcement is contingent upon socially acceptable alternatives to problem behavior (e.g., teaching communication skills). Typically, DRA is introduced under rich schedules of reinforcement. Although effective for initiating behavior change, rich schedules are often impractical in the natural setting. In this study, we evaluated the extent to which a stimulus fading program could be employed to elaborate alternative behavior (mands) in two individuals diagnosed with an Autism Spectrum Disorder. For both participants, problem behavior was reduced substantially upon implementation of the DRA procedure. Further, problem behavior rates remained low and mand rates decreased to more practical levels as the DRA behavioral requirements increased during the fading program. The fading approach demonstrated in this paper may be a useful component of intervention packages for clinicians.

Modeling the effects of sensory reinforcers on behavioral persistence with alternative reinforcement.

Problem behavior often has sensory consequences that cannot be separated from the target response, even if external, social reinforcers are removed during treatment. Because sensory reinforcers that accompany socially mediated problem behavior may contribute to persistence and relapse, research must develop analog sensory reinforcers that can be experimentally manipulated. In this research, we devised analogs to sensory reinforcers in order to control for their presence and determine how sensory reinforcers may impact treatment efficacy. Experiments 1 and 2 compared the efficacy of differential reinforcement of alternative behavior (DRA) versus noncontingent reinforcement (NCR) with and without analog sensory reinforcers in a multiple schedule. Experiment 1 measured the persistence of key pecking in pigeons, whereas Experiment 2 measured the persistence of touchscreen responses in children with intellectual and developmental disabilities. Across both experiments, the presence of analog sensory reinforcers increased the levels, persistence, and variability of responding relative to when analog sensory reinforcers were absent. Also in both experiments, target responding was less persistent under conditions of DRA compared to NCR regardless of the presence or absence of analog sensory reinforcers.

The potential influence of stimulus overselectivity in AAC: information from eye tracking and behavioral studies of attention with individuals with intellectual disabilities.

This paper examines the phenomenon of stimulus overselectivity, or overselective attention, as it may impact AAC training and use in individuals with intellectual disabilities. Stimulus overselectivity is defined as an atypical limitation in the number of stimuli or stimulus features within an image that are attended to and subsequently learned. Within AAC, the term stimulus could refer to symbols or line drawings on speech-generating devices, drawings or pictures on low-technology systems, and/or the elements within visual scene displays. In this context, overselective attention may result in unusual or uneven error patterns such as confusion between two symbols that share a single feature, or difficulties with transitioning between different types of hardware. We review some of the ways that overselective attention has been studied behaviorally. We then examine how eye tracking technology allows a glimpse into some of the behavioral characteristics of overselective attention. We describe an intervention approach, differential observing responses, that may reduce or eliminate overselectivity, and we consider this type of intervention as it relates to issues of relevance for AAC.

Thematic Matching as Remedial Teaching for Symbolic Matching for Individuals with Autism Spectrum Disorder.

Matching-to-sample (MTS) is often used to teach symbolic relationships between spoken or printed words and their referents to children with intellectual and developmental disabilities. However, many children have difficulty learning symbolic matching, even though they may demonstrate generalized identity matching. The current study investigated whether training on symbolic MTS tasks in which the stimuli are physically dissimilar but members of familiar categories (i.e., thematic matching) can remediate an individual's difficulty learning symbolic MTS tasks involving non-representative stimuli. Three adolescent males diagnosed with autism spectrum disorder were first trained on symbolic MTS tasks with unfamiliar, non-representative form stimuli. Thematic matching was introduced after the participants failed to learn 0, 2 or 4 symbolic MTS tasks and before additional symbolic MTS tasks were introduced. After exposure to thematic matching, accuracy on symbolic MTS tasks with novel stimuli increased to above chance for all participants. For two participants, high accuracy (> 90%) was achieved on a majority of these sessions. Thus, thematic matching may be an effective intervention for students with limited verbal repertoires and who have difficulty learning symbolic MTS tasks. Possible explanations for the facilitative effect of thematic matching are considered and warrant further investigation.

Merging separately established stimulus classes with outcome-specific reinforcement.

This study extended previous research on equivalence relations established with outcome-specific reinforcers to include the merger of separately established stimulus classes. Participants were four adults. Conditional discriminations AC and BC were trained first. Correct selections of C1 (C2, or C3) in the presence of A1 or B1 (A2 or B2, or A3 or B3) were followed by red (blue, or white) tokens; tokens were exchanged for value added to three participant-selected gift cards. Outcomes on equivalence tests for three-member classes ABC were positive. DF and EF were trained with the same reinforcing consequences, and tests were positive for three-member classes DEF. Results of class merger tests with combinations of stimuli from the ABC and DEF classes (AD, FB, etc.) were immediately positive for two participants, demonstrating six-member classes ABCDEF with reinforcers as nodes. Merger tests for a third participant were initially negative but became positive after brief exposure to unreinforced probe trials with reinforcers as comparison stimuli. Following class merger, tests for matching the reinforcers to samples and comparisons were also positive. Class-merger test results were negative for a fourth participant. The results provide the first demonstration of eight-member equivalence classes including two outcome-specific conditioned reinforcing stimuli.

Idiosyncratic variables that affect functional analysis outcomes: a review (2001-2010).

Although typical functional analyses often produce clear outcomes, some studies have reported ambiguous results that cannot be interpreted. Such undifferentiated outcomes may occur if test conditions do not include relevant antecedent or consequent events. Clinicians then may try to modify the functional analysis conditions to include those events. Hanley, Iwata, and McCord (2003) reviewed the functional analysis literature through 2000 and described idiosyncratic variables included in modified functional analyses. The objective of the present review was to present a quantitative analysis of idiosyncratic antecedents and consequences in modified functional analyses during the past decade (2001 to 2010). We discuss the range of stimulus parameters tested and the assessment strategies used for informing the modified analysis conditions.

Persistence during extinction: examining the effects of continuous and intermittent reinforcement on problem behavior.

This study examined behavioral persistence during extinction following continuous or intermittent reinforcement in the context of an analogue functional analysis of problem behavior. Participants were 4 children who had been diagnosed with an autism spectrum disorder and who engaged in problem behavior maintained by social reinforcement. Experimental sessions included 4 successive 5-min components: no social interaction, continuous or intermittent reinforcement for problem behavior (alternating across sessions), extinction, and no social interaction. All participants' problem behavior was more persistent during extinction following continuous reinforcement, suggesting that behavior during extinction was affected by the preceding schedule of reinforcement.

Contextual influences on resistance to disruption in children with intellectual disabilities.

Training context can influence resistance to disruption under differing reinforcement schedules. With nonhumans, when relatively lean and rich reinforcement schedules are experienced in the context of a multiple schedule, greater resistance is found in the rich than the lean component, as described by behavioral momentum theory. By contrast, when the schedules are experienced in separated blocks of sessions (i.e., as single schedules), resistance is not consistently greater in either component. In the current study, two groups of 6 children with intellectual disabilities responded to stimuli presented in relatively lean or rich components. For both, reinforcers were delivered according to the same variable-interval reinforcement schedule; additionally, the rich component included the delivery of response-independent reinforcers. The Within group was trained on a multiple schedule in which lean and rich components alternated regularly within sessions; the Blocked group was trained on two single schedules in which sessions with either the lean or rich schedule were conducted in successive blocks. Disruption tests presented a concurrently available alternative stimulus disrupter signaling the availability of tangible reinforcers. All 6 Within participants showed greater resistance to disruption in the rich component, consistent with behavioral momentum theory. By contrast, there was no consistent or significant difference in resistance for Blocked participants. This finding is potentially relevant to the development of interventions in applied settings, where such interventions often approximate single schedules and include response-independent reinforcers.

Resistance to disruption in a classroom setting.

Substantial experimental evidence indicates that behavior reinforced on a denser schedule is more resistant to disruption than is behavior reinforced on a thinner schedule. The present experiment studied resistance to disruption in a natural educational environment. Responding during familiar activities was reinforced on a multiple variable-interval (VI) 7-s VI 30-s schedule for 6 participants with developmental disabilities. Resistance to disruption was measured by presenting a distracting item. Response rates in the disruption components were compared to within-session response rates in prior baseline components. Results were consistent with the predictions of behavioral momentum theory for 5 of 6 participants.

Sample stimulus control shaping and restricted stimulus control in capuchin monkeys: a methodological note.

This paper reports use of sample stimulus control shaping procedures to teach arbitrary matching-to-sample to 2 capuchin monkeys (Cebus apella). The procedures started with identity matching-to-sample. During shaping, stimulus features of the sample were altered gradually, rendering samples and comparisons increasingly physically dissimilar. The objective was to transform identity matching into arbitrary matching (i.e., matching not based on common physical features of the sample and comparison stimuli). Experiment 1 used a two-comparison procedure. The shaping procedure was ultimately effective, but occasional high error rates at certain program steps inspired a follow-up study. Experiment 2 used the same basic approach, but with a three-comparison matching task. During shaping, the monkey performed accurately until the final steps of the program. Subsequent experimentation tested the hypothesis that the decrease in accuracy was due to restricted stimulus control by sample stimulus features that had not yet been changed in the shaping program. Results were consistent with this hypothesis, thus suggesting a new approach that may transform the sample stimulus control shaping procedure from a sometimes useful laboratory tool to a more general approach to teaching the first instance of arbitrary matching performances to participants who show protracted difficulties in learning such performances.

Evaluation of resistance to change under different disrupter conditions in children with autism and severe intellectual disability.

Translational research inspired by behavioral momentum theory in the area of developmental disabilities has shown effects in individuals over a range of functioning levels. In the current study, behavioral momentum was assessed in 6 children diagnosed with autism and severe intellectual disability. In a repeated measures design, participants were exposed to relatively rich versus lean reinforcement contingencies in a multiple schedule with food reinforcers. This was followed by exposure to each of four disrupting conditions: prefeeding, presentation of a concurrent alternative stimulus, presentation of a movie, and the presence of a researcher dispensing response-independent reinforcers on a variable-time schedule. Consistently greater resistance to disruption in the component with the richer schedule occurred with the alternative stimulus disrupter but not with the other disrupters. These results suggest parameters that may be more (or less) effective if behavioral momentum inspired techniques are to be exploited in therapeutic environments.

Observing behavior and atypically restricted stimulus control.

Restricted stimulus control refers to discrimination learning with atypical limitations in the range of controlling stimuli or stimulus features. In the study reported here, 4 normally capable individuals and 10 individuals with intellectual disabilities (ID) performed two-sample delayed matching to sample. Sample-stimulus observing was recorded with an eye-tracking apparatus. High accuracy scores indicated stimulus control by both sample stimuli for the 4 nondisabled participants and 4 participants with ID, and eye tracking data showed reliable observing of all stimuli. Intermediate accuracy scores indicated restricted stimulus control for the remaining 6 participants. Their eye-tracking data showed that errors were related to failures to observe sample stimuli and relatively brief observing durations. Five of these participants were then given interventions designed to improve observing behavior. For 4 participants, the interventions resulted initially in elimination of observing failures, increased observing durations, and increased accuracy. For 2 of these participants, contingencies sufficient to maintain adequate observing were not always sufficient to maintain high accuracy; subsequent procedure modifications restored it, however. For the 5th participant, initial improvements in observing were not accompanied by improved accuracy, an apparent instance of observing without attending; accuracy improved only after an additional intervention that imposed contingencies on observing behavior. Thus, interventions that control observing behavior seem necessary but may not always be sufficient for the remediation of restricted stimulus control.

Teaching Discrimination of Adult Gaze Direction to Children with Autism.

Three young children diagnosed with autism did not reliably locate objects in the environment on the basis of an adult's gaze shifts. A training program designed to teach gaze following used the activation of remote controlled mechanical toys as both prompts and consequences. Over several training sessions, toy activation was progressively delayed following the adult's gaze-shift cues. All of the children eventually came to anticipate the toy activation and locate the target object on the basis of the adult's gaze-shift cue alone. Discrimination of another person's gaze direction is discussed in relation to joint attention deficits in children with autism.

Behavioral Momentum: Translational Research in Intellectual and Developmental Disabilities.

Behavioral momentum theory (Nevin, 1992, Nevin & Grace, 2000) describes the relation between the characteristic level of reinforcement within a context and behavioral resistance to change within that context. This paper will describe the multiple-schedule-disrupter paradigm for basic behavioral momentum research and illustrate it with two representative examples from the literature with non-human subjects. The remainder of the paper will provide a review of translational research in human populations with intellectual and developmental disabilities (IDD) employing the multiple-schedule-disrupter paradigm and closely related variations. The results of this research show that the reinforcer-rate effects predicted by behavioral momentum theory are widely replicated in IDD populations. The intended audience for this paper is the practitioner interested in learning about the current status of translational research in behavioral momentum as a foundation for considering ways in which behavioral momentum theory may be relevant to clinical issues.