Michael E. Kelley

Within-Session Patterns of Responding during Functional Analyses: The Role of Establishing Operations in Clarifying Behavioral Function

Functional analysis procedures have been demonstrated to be effective for identifying the operant mechanisms underlying problem behavior. However, functional analyses sometimes yield results that are undifferentiated (i.e., show similar levels of responding across test conditions). Within-session (i.e., minute-by-minute) analyses of response patterns during undifferentiated functional analyses have proven useful in clarifying behavioral function. This study extends previous research by examining within-session changes in responding associated with variations in relevant establishing operations. Levels of problem behavior during the presentation and removal of reinforcement were compared when responding occurred in test conditions associated with sources of social reinforcement (i.e., access to attention, materials, escape). Results showed that changes in responding associated with changes in relevant establishing operations could be examined to clarify behavioral function.

Real-time size discrimination and elemental analysis of gold nanoparticles using ES-DMA coupled to ICP-MS

We report the development of a hyphenated instrument with the capacity to quantitatively characterize aqueous suspended gold nanoparticles (AuNPs) based on a combination of gas-phase size separation, particle counting, and elemental analysis. A customized electrospray-differential mobility analyzer (ES-DMA) was used to achieve real-time upstream size discrimination. A condensation particle counter and inductively coupled plasma mass spectrometer (ICP-MS) were employed as downstream detectors, providing information on number density and elemental composition, respectively, of aerosolized AuNPs versus the upstream size selected by ES-DMA. A gas-exchange device was designed and optimized to improve the conversion of air flow (from the electrospray) to argon flow required to sustain the ICP-MS plasma, the key compatibility issue for instrumental hyphenation. Our work provides the proof of concept and a working prototype for utilizing this construct to successfully measure (1) number- and mass-based distributions; (2) elemental compositions of nanoparticles classified by size, where the size classification and elemental analysis are performed within a single experiment; (3) particle concentrations in both solution (before size discrimination) and aerosol (after size discrimination) phases; and (4) the number of atoms per nanoparticle or the nanoparticle density.

The effects of variable-time delivery of food items and praise on problem behavior reinforced by escape.

Prior research indicates that reinforcement of an appropriate response (e.g., compliance) can produce concomitant reductions in problem behavior reinforced by escape when problem behavior continues to produce negative reinforcement (e.g., Lalli et al., 1999). These effects may be due to a preference for positive over negative reinforcement or to positive reinforcement acting as an abolishing operation, rendering demands less aversive and escape from demands less effective as negative reinforcement. In the current investigation, we delivered a preferred food item and praise on a variable-time 15-s schedule while providing escape for problem behavior on a fixed-ratio 1 schedule in a demand condition for 3 participants with problem behavior maintained by negative reinforcement. Results for all 3 participants showed that variable-time delivery of preferred edible items reduced problem behavior even though escape continued to be available for these responses. These findings are discussed in the context of motivating operations.

Comparison of traditional and trial-based methodologies for conducting functional analyses

Functional analysis represents a sophisticated and empirically supported functional assessment procedure. While these procedures have garnered considerable empirical support, they are often underused in clinical practice. Safety risks resulting from the evocation of maladaptive behavior and the length of time required to conduct functional analyses may deter practitioners from using models of assessment with considerable empirical support. The current study evaluated a trial-based model of functional analysis that limited opportunities to engage in problem behavior and used 1-2 min sessions to shorten analysis time. The results from the trial-based analysis were then compared to the results of traditional functional analyses. Correspondence between both models of assessment was strong. Exact correspondence was observed for 4 of the 5 participants. In addition, the trial-based procedure did not require the repeated reinforcement of maladaptive behavior and results were obtained in 84.8% less time.

Basic and translational evaluation of renewal of operant responding.

Treatment relapse, defined as the reemergence of problem behavior after treatment, is a serious difficulty faced by clinicians. Failures of treatment integrity (i.e., failure to implement interventions as intended) are often invoked to explain the reemergence of problem behavior. Basic studies suggest that the prevailing stimulus context might also contribute. We conducted 2 experiments in which reinforcement for a target response was followed by 2 phases of extinction with different or identical stimulus contexts relative to baseline (ABA renewal). In Experiment 1, pigeons served as subjects using procedures typical of those used in basic behavioral research. Experiment 2 was designed as a translational replication of Experiment 1, and children who had been diagnosed with autism served as participants. Returning to the previously reinforced stimulus context in both species produced a clear and immediate increase of extinguished responding. These findings are consistent with previous studies that have suggested that both reinforcement contingencies and stimulus context influence the reemergence of extinguished behavior.

Using modified visual-inspection criteria to interpret functional analysis outcomes.

The development of functional analysis (FA) methodologies allows the identification of the reinforcers that maintain problem behavior and improved intervention efficacy in the form of function-based treatments. Despite the profound impact of FA on clinical practice and research, questions still remain about the methods by which clinicians and researchers interpret FA graphs. In the current study, 141 FA data sets were evaluated using the structured visual-inspection criteria developed by Hagopian et al. (1997). However, the criteria were modified for FAs of varying lengths. Interobserver agreement assessments revealed high agreement coefficients across expert judges, postdoctoral reviewers, masters-level reviewers, and postbaccalaureate reviewers. Once the validity of the modified visual-inspection procedures was established, the utility of those procedures was examined by using them to categorize the maintaining reinforcement contingency related to problem behavior for all 141 data sets and for the 101 participants who contributed to the 141 data sets.

Renewed behavior produced by context change and its implications for treatment maintenance: A review

Behavioral treatment gains established in one setting do not always maintain in other settings. The present review examines the relevance of basic and translational research to understanding failures to maintain treatment gains across settings. Specifically, studies of the renewal effect examine how transitioning away from a treatment setting could evoke a return of undesirable behavior, rather than newly trained appropriate behavior. Studies of renewal typically arrange three phases, with a response trained and reinforced under a particular set of contextual stimuli in the first phase. Next, that response is extinguished, often under a different set of contextual stimuli. Finally, that response returns despite extinction remaining in effect upon returning to the original training context or transitioning to a novel context. Thus, removing the extinction context is sufficient to produce a recurrence of the response. The findings suggest treatment effects can become specific to the context in which the treatment was delivered. This literature offers promising methods for systematically assessing the factors contributing to treatment maintenance and improving generalization of treatment gains across contexts. Therefore, the present review suggests basic and translational research on renewal provides an empirical literature to bring greater conceptual systematization to understanding generalization and maintenance of behavioral treatment.

EVALUATION AND TRAINING OF YES–NO RESPONDING ACROSS VERBAL OPERANTS

Topographically similar verbal responses may be functionally independent forms of operant behavior. For example, saying yes or no may have different functions based on the environmental conditions in effect. The present study extends previous research on both the assessment and acquisition of yes and no responses across contexts in children with language deficits and further examined the functional independence of topographically similar responses. All participants in the present study acquired yes and no responses within verbal operants (e.g., mands). However, generalization of the responses across novel verbal operants (e.g., tacts to intraverbals) did not occur without additional training, thus supporting Skinners (1957) assertion of functional independence of verbal operants.

Comparing preference assessments: selection- versus duration-based preference assessment procedures.

In the current investigation, the results of a selection- and a duration-based preference assessment procedure were compared. A Multiple Stimulus With Replacement (MSW) preference assessment [Windsor, J., Piché, L. M., & Locke, P. A. (1994). Preference testing: A comparison of two presentation methods. Research in Developmental Disabilities, 15, 439-455] and a variation of a Free-Operant (FO) preference assessment procedure [Roane, H. S., Vollmer, T. R., Ringdahl, J. E., & Marcus, B. A. (1998). Evaluation of a brief stimulus preference assessment. Journal of Applied Behavior Analysis, 31, 605-620] were conducted with four participants. A reinforcer assessment was conducted to determine which preference assessment procedure identified the item that produced the highest rates of responding. The items identified as most highly preferred were different across preference assessment procedures for all participants. Results of the reinforcer assessment showed that the MSW identified the item that functioned as the most effective reinforcer for two participants.

FUNCTIONAL ANALYSIS AND TREATMENT OF HUMAN-DIRECTED UNDESIRABLE BEHAVIOR EXHIBITED BY A CAPTIVE CHIMPANZEE

A functional analysis identified the reinforcer maintaining feces throwing and spitting exhibited by a captive adult chimpanzee (Pan troglodytes). The implementation of a function-based treatment combining extinction with differential reinforcement of an alternate behavior decreased levels of inappropriate behavior. These findings further demonstrate the utility of function-based approaches to assess and treat behavior problems exhibited by captive animals.