Iser G. DeLeon

INITIAL FUNCTIONAL ANALYSIS OUTCOMES AND MODIFICATIONS IN PURSUIT OF DIFFERENTIATION: A SUMMARY OF 176 INPATIENT CASES

The functional analysis (FA) described by Iwata, Dorsey, Slifer, Bauman, and Richman (1982/1994) delineated not only a set a specific procedures, but also a model that involves the use of analogue conditions wherein antecedent and consequent variables are systematically manipulated. This consecutive case-series analysis describes FAs of 176 individuals with intellectual disabilities who had been admitted to an inpatient unit for severe problem behavior. Following an initial standardized FA, additional modifications were performed in pursuit of differentiation. Ultimately, a function was identified in 86.9% of the 176 cases and in 93.3% of the 161 cases for which the FA, if necessary, was modified up to 2 times. All modifications were documented and classified as involving changes to antecedents, consequences, or design (or some combination of these). Outcomes for each type of modification are reported. The results support the utility of ongoing hypothesis testing through individualized modifications to FA procedures, and provide information regarding how each type of modification affected results.

Learning processes affecting human decision making: An assessment of reinforcer-selective pavlovian-to-instrumental transfer following reinforcer devaluation

In reinforcer-selective transfer, Pavlovian stimuli that are predictive of specific outcomes bias performance toward responses associated with those outcomes. Although this phenomenon has been extensively examined in rodents, recent assessments have extended to humans. Using a stock market paradigm adults were trained to associate particular symbols and responses with particular currencies. During the first test, individuals showed a preference for responding on actions associated with the same outcome as that predicted by the presented stimulus (i.e., a reinforcer-selective transfer effect). In the second test of the experiment, one of the currencies was devalued. We found it notable that this served to reduce responses to those stimuli associated with the devalued currency. This finding is in contrast to that typically observed in rodent studies, and suggests that participants in this task represented the sensory features that differentiate the reinforcers and their value during reinforcer-selective transfer. These results are discussed in terms of implications for understanding associative learning processes in humans and the ability of reward-paired cues to direct adaptive and maladaptive behavior.

ON THE CORRESPONDENCE BETWEEN PREFERENCE ASSESSMENT OUTCOMES AND PROGRESSIVE-RATIO SCHEDULE ASSESSMENTS OF STIMULUS VALUE

The current study examined whether stimuli of different preference levels would be associated with different amounts of work maintained by the stimuli, as determined through progressive-ratio schedule break points. Using a paired-choice preference assessment, stimuli were classified as high, moderate, or low preference for 4 individuals with developmental disabilities. The stimuli were then tested three times each using a progressive-ratio schedule (step size of 1; the break-point criterion was 1 min). In 10 of 12 possible comparisons, higher preference stimuli produced larger break points than did lower preference stimuli.

The Influence of Matching and Motor-Imitation Abilities on Rapid Acquisition of Manual Signs and Exchange-Based Communicative Responses.

Establishing a relation between existing skills and acquisition of communicative responses may be useful in guiding selection of alternative communication systems. Matching and motor-imitation skills were assessed for 6 children with developmental disabilities, followed by training to request the same set of preferred items using exchange-based communication and manual signs. Three participants displayed both skills and rapidly acquired both communicative response forms. Three others displayed neither skill; 1 mastered exchange-based responses but not manual signs, and neither of the other 2 easily acquired either response form.

The translational utility of behavioral economics: The experimental analysis of consumption and choice.

More than a decade ago, E. O. Wilson (1998), the founder of sociobiology, an expert in ant societies, and a specialist in evolution, argued that consilience would advance an interdisciplinary and unified science. The term consilience was borrowed from the 19th-century historian and philosopher of science William Whewell (1794–1866). Whewell posited that in the rhetoric of scientific discourse, statements of empirical truth are more convincing if three criteria are met: prediction, coherence, and consilience. In this terminology, coherence extends well-established functional relations to other observations without ad hoc modification, and consilience extends scientific propositions about mechanisms and determinants to phenomena and investigative methodologies different from those originally contemplated (Snyder, 2009). The relatively new field of behavioral economics may represent an example of consilience in which concepts from microeconomic theory are extended to the study of consumption by a range of species in the laboratory and the concepts of operant conditioning are extended to an understanding of demand for economic commodities. The blending of behavioral principles with microeconomic theory has been a fruitful area of research (e.g., Kagel, Battalio, & Green, 1995) and has provided a translational framework for extending principles derived from laboratory studies to an understanding of consumer choice observed in whole communities. Economics and behavioral psychology have several points of convergence. One is a common interest in the value of goods, defined as reinforcers by the behaviorist and as objects of scarce consumption by economists. A second point of convergence is an interest in the process of choice: for the economist, the allocation of limited resources for the consumption of alternative goods (consumer choice), and for the behaviorist, the division of operant behavior among competing reinforcers. One area of divergence is that behavioral economists in the operant tradition have focused very little on hypothetical economic concepts, such as utility functions, indifference curves, and optimal choices. Instead, research efforts have focused on understanding the environmental factors affecting (a) overall levels of behavior that is instrumental in obtaining or consuming a variety of commodities in closed economic systems (Bickel, DeGrandpre, Higgins, & Hughes, 1990; Bickel, DeGrandpre, Hughes, & Higgins, 1991; Foltin, 1992; Hursh, 1984; Lea, 1978; Lea & Roper, 1977; Rashotte & Henderson, 1988) and (b) the allocation of behavioral resources among available reinforcers (Hursh, 1980, 1984; Hursh & Bauman, 1987; Madden, Smethells, Ewan, & Hursh, 2007a, 2007b). Behavioral economics, as practiced by students of operant conditioning and behavior analysis, has

Unexamined Potential Effects of the Noncontingent Delivery of Reinforcers

Noncontingent reinforcement (NCR) is a therapeutic arrangement in which the reinforcer hypothesized to maintain a problem behavior, or another preferred stimulus, is delivered on a response-independent, time-based schedule. Several investigations have determined that this form of intervention is effective in decreasing problem behavior maintained by both positive and negative reinforcement. However, it seems possible that this sort of intervention may have unknown side effects under certain arrangements. Some of these (e.g., the potential for adventitious reinforcement) have been documented, but others have not been directly examined. This paper discusses some of these less considered or unconsidered possible effects, some of which may be detrimental. Specific effects include the relation between contingency and stimulus value, behavioral and hedonic contrast, behavioral momentum and the discriminative functions of reinforcers. We further discuss the conditions under which these effects may or may not occur, and address their implications for future research on NCR.

Behavioral Momentum Theory: Understanding Persistence and Improving Treatment

Behavioral momentum theory is a quantitative framework asserting that reinforcers obtained in the presence of a discriminative-stimulus context govern the persistence of behavior, as defined as resistance to disruption and relapse. An important implication of the theory is that behavioral treatments that decrease problem behavior by arranging alternative sources of reinforcement within the same stimulus context can inadvertently increase the persistence of problem behavior. This chapter describes behavioral momentum theory at a conceptual level and presents an empirical body of basic and applied research supporting its assertions. In addition, we evaluate a novel solution for treating problem behavior based on behavioral momentum theory. Specifically, training a desirable alternative behavior in a separate context before combining with the problem-behavior context results in less persistent problem behavior than training the alternative and problem behavior together. Although this novel approach provides an initially promising alternative to traditional treatments, we provide evidence that more research is needed to understand its potential impact on problem behavior. We argue that a translational program combining the expertise of basic and applied researchers will be more effective for developing and establishing best practices for this or any behavioral treatment for problem behavior.

Assessment of Aberrant Behavior Maintained by Wheelchair Movement in a Child with Developmental Disabilities.

A child that used a wheelchair was anecdotally observed to display little aggressive behavior when being pushed in his wheelchair, but higher rates of aggressive behavior when movement was terminated. A functional analysis was conducted to systematically assess the relationship between aggression and wheelchair movement. The functional analysis results revealed elevated rates of aggression when it resulted in being briefly pushed in the wheelchair. This functional hypothesis was subsequently validated by teaching the child to request movement through appropriate means and demonstrating that aggression decreased under treatment conditions. These results extend prior research on functional analysis by demonstrating a previously unreported behavioral function particular to individuals with motor deficits.

Examination of the influence of contingency on changes in reinforcer value.

This study examined how the amount of effort required to produce a reinforcer influenced subsequent preference for, and strength of, that reinforcer in 7 individuals with intellectual disabilities. Preference assessments identified four moderately preferred stimuli for each participant, and progressive-ratio (PR) analyses indexed reinforcer strength. Stimuli were then assigned to one of four conditions for 4 weeks: fixed-ratio (FR) 1 schedule, escalating FR schedule, yoked noncontingent (NCR) delivery, and restricted access. Preference assessments and PR schedules were then repeated to examine changes in selection percentages and PR break points. Selection percentages decreased for all NCR stimuli but increased for most of the restricted stimuli. There were no systematic changes in selection percentages for either of the contingent stimuli. Break points increased, on average, for all conditions, but the increase was highest for the restricted stimuli and lowest for the NCR stimuli. These results are discussed in relation to recent basic research addressing the influence of effort on stimulus value.

Effects of signaled and unsignaled alternative reinforcement on persistence and relapse in children and pigeons.

Three experiments explored the impact of different reinforcer rates for alternative behavior (DRA) on the suppression and post-DRA relapse of target behavior, and the persistence of alternative behavior. All experiments arranged baseline, intervention with extinction of target behavior concurrently with DRA, and post-treatment tests of resurgence or reinstatement, in two- or three-component multiple schedules. Experiment 1, with pigeons, arranged high or low baseline reinforcer rates; both rich and lean DRA schedules reduced target behavior to low levels. When DRA was discontinued, the magnitude of relapse depended on both baseline reinforcer rate and the rate of DRA. Experiment 2, with children exhibiting problem behaviors, arranged an intermediate baseline reinforcer rate and rich or lean signaled DRA. During treatment, both rich and lean DRA rapidly reduced problem behavior to low levels, but post-treatment relapse was generally greater in the DRA-rich than the DRA-lean component. Experiment 3, with pigeons, repeated the low-baseline condition of Experiment 1 with signaled DRA as in Experiment 2. Target behavior decreased to intermediate levels in both DRA-rich and DRA-lean components. Relapse, when it occurred, was directly related to DRA reinforcer rate as in Experiment 2. The post-treatment persistence of alternative behavior was greater in the DRA-rich component in Experiment 1, whereas it was the same or greater in the signaled-DRA-lean component in Experiments 2 and 3. Thus, infrequent signaled DRA may be optimal for effective clinical treatment.