Testosterone and explosive aggression in autism spectrum disorders.

Autism spectrum disorders (ASD) are a set of heterogeneous neurodevelopmental conditions, characterized by early-onset difficulties in social communication and unusually restricted, repetitive behavior and interests. Children with ASD have a high rate of irritability and aggressive symptoms which have significant impact on their lives, families and society. The etiology of aggression in humans is likely complex and includes both biological and behavioral causes. Biological approaches have focused on hormones and neurotransmitters that are hypothesized to contribute to the etiology and clinical manifestation of aggressive behavior in humans. Testosterone is a male sex hormone and some studies suggest that it can play a role in the complex etiology of aggressive behavior. Two specific subtypes of aggression have been identified: explosive and non-explosive. Explosive aggression is accompanied by a raged affect and is usually more dangerous and not immediately responsive to behavioral treatment. In our review we would like to provide current findings and discuss potential limitation of research in this area. We propose to determine bio-behavioral model of explosive aggression in children with ASD which will predict which children will be most responsive to potential antiandrogen therapy and behavioral therapy.

The Persistence-Strengthening Effects of DRA: An Illustration of Bidirectional Translational Research.

We summarize a series of bidirectional research studies that demonstrate the persistence-strengthening effects of differential reinforcement of alternative behavior on problem behavior. We model a possible solution to this problem with rats followed by replication with a human clinical population. The importance of coordinated basic and applied research to stimulate new behavioral technologies is emphasized.

Training Staff to Avoid Problem Behavior Related to Restricting Access to Preferred Activities.

Some training programs for staff working with individuals with intellectual disabilities fail to equip staff with the practical skills necessary to prevent behavioral episodes. The current research describes the results of a staff training program that, following traditional didactic training, used a card game followed by role-play training to increase staff competence in managing problem behavior. The card game and role-play training was based on behavioral episodes that had occurred previously in the research setting. Post-training observations showed that treatment integrity of trained staff improved.

A computerized test of self-control predicts classroom behavior.

We assessed choices on a computerized test of self-control (CTSC) for a group of children with features of attention deficit hyperactivity disorder (ADHD) and a group of controls. Thirty boys participated in the study. Fifteen of the children had been rated by their parents as hyperactive and inattentive, and 15 were age- and gender-matched controls in the same classroom. The children were observed in the classroom for three consecutive mornings, and data were collected on their activity levels and attention. The CTSC consisted of two tasks. In the delay condition, children chose to receive three rewards after a delay of 60 s or one reward immediately. In the task-difficulty condition, the children chose to complete a difficult math problem and receive three rewards or complete an easier problem for one reward. The children with ADHD features made more impulsive choices than their peers during both conditions, and these choices correlated with measures of their activity and attention in the classroom.

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.

Treatment relapse and behavioral momentum theory.

The relapse of problem behavior after apparently successful treatment is an enduring problem for the field of applied behavior analysis. Several theoretical accounts of treatment relapse have emerged over the years. However, one account that has received considerable recent attention is based on behavioral momentum theory (BMT). BMT has shown that behavior is more persistent in contexts that are correlated with higher rates of reinforcers after disruption of the response-reinforcer relation. Accordingly, relapse after successful treatment can be viewed as the persistence of behavior when treatment is compromised in some manner. We review basic BMT research, alternative accounts of treatment relapse, and translational research studies derived from BMT research. The implications for applied behavior analysis in practice are discussed along with potential solutions to the problem of treatment relapse.

Clinical translation of animal models of treatment relapse.

Behavioral Momentum Theory (BMT) has inspired animal models of treatment relapse. We translated the models of reinstatement and resurgence into clinical procedures to test whether relapse tests would replicate behavior pattern found in basic research. Following multiple schedule baseline reinforcement of a 16-year-old male's problem behavior at equal rates by two therapists, treatment was introduced using a variable-interval, variable-time (VI VT) schedule arrangement with therapists delivering reinforcers at different rates. Despite the differing rates of VI VT reinforcers, the treatment produced comparable reductions in problem behavior. Following successful treatment, the two therapists discontinued treatment and resumed reinforcement of problem behavior at equal rates that constituted a reinstatement of baseline conditions. As predicted by BMT, reinstatement resulted in an immediate return of high rates of problem behavior but was 2.6 times higher for the therapist using the higher rate VI VT treatment. A second treatment phase was implemented followed by a test of resurgence in a single extended extinction session conducted separately for each therapist. The unequal VI VT treatment rates by therapists resulted in 2.1 times greater responding in the resurgence test for the therapist who implemented the higher rate VI VT procedure. These results are consistent with basic research studies and BMT.

An evaluation of three methods of saying "no" to avoid an escalating response class hierarchy.

We evaluated the effects of three different methods of denying access to requested high-preference activities on escalating problem behavior. Functional analysis and response class hierarchy (RCH) assessment results indicated that 4 topographies of problem behaviors displayed by a 13-year-old boy with high-functioning autism constituted an RCH maintained by positive (tangible) reinforcement. Identification of the RCH comprised the baseline phase, during which computer access was denied by saying "no" and providing an explanation for the restriction. Two alternative methods of saying "no" were then evaluated. These methods included (a) denying computer access while providing an opportunity to engage in an alternative preferred activity and (b) denying immediate computer access by arranging a contingency between completion of a low-preference task and subsequent computer access. Results indicated that a hierarchy of problem behavior may be identified in the context of denying access to a preferred activity and that it may be possible to prevent occurrences of escalating problem behavior by either presenting alternative options or arranging contingencies when saying "no" to a child's requests.

Translational research in behavior analysis: historical traditions and imperative for the future.

"Pure basic" science can become detached from the natural world that it is supposed to explain. "Pure applied" work can become detached from fundamental processes that shape the world it is supposed to improve. Neither demands the intellectual support of a broad scholarly community or the material support of society. Translational research can do better by seeking innovation in theory or practice through the synthesis of basic and applied questions, literatures, and methods. Although translational thinking has always occurred in behavior analysis, progress often has been constrained by a functional separation of basic and applied communities. A review of translational traditions in behavior analysis suggests that innovation is most likely when individuals with basic and applied expertise collaborate. Such innovation may have to accelerate for behavior analysis to be taken seriously as a general-purpose science of behavior. We discuss the need for better coordination between the basic and applied sectors, and argue that such coordination compromises neither while benefiting both.

The effects of constant versus varied reinforcers on preference and resistance to change.

Previous research has demonstrated that factors such as reinforcer frequency, amount, and delay have similar effects on resistance to change and preference. In the present study, 4 boys with autism made choices between a constant reinforcer (one that was the same food item every trial) and a varied food reinforcer (one that varied randomly between three possible food items). For all 4 boys, varied reinforcers were preferred over constant reinforcers, and they maintained higher response rates than constant reinforcers. In addition, when a distraction (a video clip) was introduced, responding maintained by varied reinforcers was more resistant to distraction than responding maintained by constant reinforcers. Thus, the present experiment extended the generality of the relation between preference and resistance to change to variation in reinforcer quality.

Differential reinforcement of alternative behavior increases resistance to extinction: clinical demonstration, animal modeling, and clinical test of one solution.

Basic research with pigeons on behavioral momentum suggests that differential reinforcement of alternative behavior (DRA) can increase the resistance of target behavior to change. This finding suggests that clinical applications of DRA may inadvertently increase the persistence of target behavior even as it decreases its frequency. We conducted three coordinated experiments to test whether DRA has persistence-strengthening effects on clinically significant target behavior and then tested the effectiveness of a possible solution to this problem in both a nonhuman and clinical study. Experiment 1 compared resistance to extinction following baseline rates of reinforcement versus higher DRA rates of reinforcement in a clinical study. Resistance to extinction was substantially greater following DRA. Experiment 2 tested a rat model of a possible solution to this problem. Training an alternative response in a context without reinforcement of the target response circumvented the persistence-strengthening effects of DRA. Experiment 3 translated the rat model into a novel clinical application of DRA. Training an alternative response with DRA in a separate context resulted in lower resistance to extinction than employing DRA in the context correlated with reinforcement of target behavior. The value of coordinated bidirectional translational research is discussed.

Effects of stimulant medication under varied motivational operations.

We evaluated the evocative effects of four conditions (high- and low-preference activities, low and divided attention) and stimulant medication on the behavior of a 16-year-old boy with attention deficit hyperactivity disorder and moderate mental retardation. All behavior (activity engagement, activity changes, inappropriate touching, rude behaviors, and physical aggression) improved with stimulant medication in most conditions, but undesirable behaviors were not reduced to acceptable levels in all conditions. This finding suggests that stimulant medication may be a valuable adjunct to function-based interventions.