Biomedical subjects

R H Thompson

Publications and source records attributed to R H Thompson.

At least 19 recordsLinked to original sources

PubMed2000

Facilitating tolerance of delayed reinforcement during functional communication training.

Few clinical investigations have addressed the problem of delayed reinforcement. In this investigation, three individuals whose destructive behavior was maintained by positive reinforcement were treated using functional communication training (FCT) with extinction (EXT). Next, procedures used in the basic literature on delayed reinforcement and self-control (reinforcer delay fading, punishment of impulsive responding, and provision of an alternative activity during reinforcer delay) were used to teach participants to tolerate delayed reinforcement. With the first case, reinforcer delay fading alone was effective at maintaining low rates of destructive behavior while introducing delayed reinforcement. In the second case, the addition of a punishment component reduced destructive behavior to near-zero levels and facilitated reinforcer delay fading. With the third case, reinforcer delay fading was associated with increases in masturbation and head rolling, but prompting and praising the individual for completing work during the delay interval reduced all problem behaviors and facilitated reinforcer delay fading.

Adult↗

PubMed2000

Response acquisition under direct and indirect contingencies of reinforcement.

We compared the effects of direct and indirect reinforcement contingencies on the performance of 6 individuals with profound developmental disabilities. Under both contingencies, completion of identical tasks (opening one of several types of containers) produced access to identical reinforcers. Under the direct contingency, the reinforcer was placed inside the container to be opened; under the indirect contingency, the therapist held the reinforcer and delivered it to the participant upon task completion. One participant immediately performed the task at 100% accuracy under both contingencies. Three participants showed either more immediate or larger improvements in performance under the direct contingency. The remaining 2 participants showed improved performance only under the direct reinforcement contingency. Data taken on the occurrence of "irrelevant" behaviors under the indirect contingency (e.g., reaching for the reinforcer instead of performing the task) provided some evidence that these behaviors may have interfered with task performance and that their occurrence was a function of differential stimulus control.

Adult↗

PubMed2000

Effects of continuous and intermittent reinforcement for problem behavior during functional communication training.

We evaluated the effectiveness of functional communication training (FCT) in reducing problem behavior and in strengthening alternative behavior when FCT was implemented without extinction. Following the completion of functional analyses in which social-positive reinforcement was identified as the maintaining variable for 5 participants' self-injurious behavior (SIB) and aggression, the participants were first exposed to FCT in which both problem behavior and alternative behavior were reinforced continuously (i.e., on fixed-ratio [FR] 1 schedules). During subsequent FCT conditions, the schedule of reinforcement for problem behavior was made more intermittent (e.g., FR 2, FR 3, FR 5, etc.), whereas alternative behavior was always reinforced according to an FR 1 schedule. Results showed that 1 participant's problem behavior decreased and alternative behavior increased during FCT when both behaviors were reinforced on FR 1 schedules. The remaining 4 participants shifted response allocation from problem to alternative behavior as the schedule of reinforcement for problem behavior became more intermittent. These results suggest that individuals might acquire alternative responses during FCT in spite of inconsistencies in the application of extinction, although even small errors in reinforcement may compromise treatment effects.

Adult↗

PubMed2000

Skill acquisition in the implementation of functional analysis methodology.

Functional analysis methodology is a powerful assessment tool for identifying contingencies that maintain a wide range of behavior disorders and for developing effective treatment programs. Nevertheless, concerns have been raised about the feasibility of conducting functional analyses in typical service settings. In this study, we examined the issue of skill acquisition in implementing functional analyses by evaluating an instructional program designed to establish a basic set of competencies. Eleven undergraduate students enrolled in a laboratory course in applied behavior analysis served as participants. Their performance was assessed during scripted simulations in which they played the roles of "therapists" who conducted functional analyses and trained graduate students played the roles of "clients" who emitted self-injurious and destructive behaviors. To approximate conditions under which an individual might conduct an assessment with limited prior training, participants read a brief set of materials prior to conducting baseline sessions. A multiple baseline design was used to assess the effects of training, which consisted of reading additional materials, watching a videotaped simulation demonstrating correct procedural implementation, passing a written quiz, and receiving feedback on performance during sessions. Results showed that participants scored a relatively high percentage of correct therapist responses during baseline, and that all achieved an accuracy level of 95% or higher following training that lasted about 2 hr. These results suggest that basic skills for conducting functional analyses can be acquired quickly by individuals who have relatively little clinical experience.

Feasibility Studies↗

PubMed1999

Reinforcement of compliance with respiratory treatment in a child with cystic fibrosis.

An 8-year-old boy with cystic fibrosis (CF), mental retardation, and autism exhibited noncompliance with respiratory treatments that were essential for the management of his CF. A treatment involving shaping cooperation while still allowing escape for aggression and avoidance behavior resulted in increases compliance with respiratory treatments and decreases in problem behavior. Treatment gains were maintained over 3 months.

Aggression↗

PubMed1999

Effects of reinforcement for alternative behavior during punishment of self-injury.

A number of variables influence the effectiveness of punishment and may determine the extent to which less intrusive forms of punishment may be used as alternatives to more intrusive interventions. For example, it has been suggested that response suppression during punishment may be facilitated if reinforcement is concurrently available for an alternative response. However, results of basic research demonstrating this finding have not been replicated with interventions more commonly prescribed as treatments for problem behavior. We evaluated the effects of relatively benign punishment procedures (reprimands or brief manual restraint) on the self-injurious behavior of 4 individuals who had been diagnosed with mental retardation, when access to reinforcement for alternative behavior (manipulation of leisure materials) was and was not available. In all cases, punishment produced greater response suppression when reinforcement for an alternative response was available.

Adult↗

PubMed1998

Organization of inputs to the dorsomedial nucleus of the hypothalamus: a reexamination with Fluorogold and PHAL in the rat.

Possible inputs to the DMH were studied first using the fluorescent retrograde tracer Fluorogold, and identified cell groups were then injected with the anterograde tracer PHAL to examine the distribution of labeled axons in and around the DMH. From this work, we conclude that the majority of inputs to the DMH arise in the hypothalamus, although there are a few significant projections from the telencephalon and brainstem. With few exceptions, each major nucleus and area of the hypothalamus provides inputs to the DMH. Telencephalic inputs arise mainly in the ventral subiculum, infralimbic area of the prefrontal cortex, lateral septal nucleus, and bed nuclei of the stria terminalis. The majority of brainstem inputs arise in the periaqueductal gray, parabrachial nucleus, and ventrolateral medulla. In addition, it now seems clear that inputs to the DMH use only a few discrete pathways. Descending inputs course through a periventricular pathway through the hypothalamic periventricular zone, a medial pathway that follows the medial corticohypothalamic tract, and a lateral pathway traveling through medial parts of the medial forebrain bundle. Ascending inputs arrive through a midbrain periventricular pathway that travels adjacent to the cerebral aqueduct in the periaqueductal gray, and through a brainstem lateral pathway that travels through central and ventral midbrain tegmental fields and enters the hypothalamus, and then the DMH from more lateral parts of the medial forebrain bundle. The results are discussed in relation to evidence for involvement of the DMH in ingestive behavior, and diurnal and stress-induced corticosterone secretion.

Animals↗

PubMed1998

The evaluation and treatment of aggression maintained by attention and automatic reinforcement.

In the current investigation, we used direct and indirect methods to assess and treat several topographies of aggression that were hypothesized to have separate operant functions in a young boy with severe mental ratardation and pervasive developmental disorder. First, a functional analysis of aggression, using the methods described by Iwata, Dorsey, Slifer, Bauman, and Richman (1982/1994), was conducted and produced inconclusive results. Next, indirect methods were used to develop a second functional analysis, which showed that chin grinding (firmly pressing and grinding his chin against the skin and bones of others) persisted independent of social contingencies and that the other topographies of aggression (e.g., hitting, kicking) were maintained by social positive reinforcement (attention). A treatment designed to decrease aggression maintained by attention--functional communication training with extinction--reduced all forms of aggression except chin grinding. This latter topography of aggression, which we hypothesized was maintained by automatic reinforcement, was reduced when the response--reinforcer relation was interrupted through response blocking and the child was provided with an alternative form of chin stimulation.

Aggression↗

PubMed1998

Functional analysis and treatment of destructive behavior maintained by termination of "don't" (and symmetrical "do") requests.

We used descriptive assessment information to generate hypotheses regarding the function of destructive behavior for 2 individuals who displayed near-zero rates of problem behavior during an experimental functional analysis using methods similar to Iwata, Dorsey, Slifer, Bauman, and Richman (1982/1994). The descriptive data suggested that destructive behavior occurred primarily when caregivers issued requests to the participants that interfered with ongoing high-probability (and presumably highly preferred) behaviors (i.e., a "don't" or a symmetrical "do" request). Subsequent experimental analyses showed that destructive behavior was maintained by contingent termination of "don't" and symmetrical "do" requests but not by termination of topographically similar "do" requests. These results suggested that destructive behavior may have been maintained by positive reinforcement (i.e., termination of the "don't" request allowed the individual to return to a highly preferred activity). Finally, a treatment (functional communication training plus extinction) developed on the basis of these analyses reduced destructive behavior to near-zero levels.

Adolescent↗

PubMed1998

Reductions in self-injury produced by transcutaneous electrical nerve stimulation.

Transcutaneous electrical nerve stimulation is used to reduce pain but also may be useful for self-injurious behavior (SIB). In the current investigation, a microcurrent electromedical device, classified as a transcutaneous electrical nerve stimulator (TENS), was applied with a man with Down syndrome who displayed SIB that persisted in the absence of social contingencies. Although clinically significant results were not maintained, a clear difference in the rates of SIB during active and inactive TENS was observed.

Adult↗

PubMed1998

Assessment and treatment of destructive behavior maintained by stereotypic object manipulation.

In the current investigation, 2 participants with mental retardation displayed property destruction and stereotypy, and both responses involved the same materials (e.g., breaking and tapping plastic objects). Three experiments were conducted (a) to indirectly assess the functions of these two responses, (b) to determine their relation to one another, and (c) to develop a treatment to reduce the more serious behavior, property destruction. In Experiment 1, previously destroyed materials were either present or absent, and their presence reduced property destruction but not stereotypy. In Experiment 2, matched toys (ones that produced sensory stimulation similar to stereotypy) were either present or absent, or were replaced by unmatched toys (for 1 participant). Matched toys produced large reductions and unmatched toys produced small reductions in property destruction and stereotypy. In Experiment 3, attempts to pick up undestroyed objects were either blocked or not blocked while matched toys were continuously available. Response blocking reduced property destruction (and attempts), prevented stereotypy, and increased manipulation of matched toys. These results suggest that the two aberrant responses formed a chain (e.g., breaking and then tapping the object), which was maintained by the sensory consequences (e.g., auditory stimulation) of the terminal response, and that previously destroyed material or matched toys made the initial response (property destruction) unnecessary.

Adolescent↗

PubMed1998

Establishing discriminative control of responding using functional and alternative reinforcers during functional communication training.

Functional communication training (FCT) is a popular treatment for problem behaviors, but its effectiveness may be compromised when the client emits the target communication response and reinforcement is either delayed or denied. In the current investigation, we trained 2 individuals to emit different communication responses to request (a) the reinforcer for destructive behavior in a given situation (e.g., contingent attention in the attention condition of a functional analysis) and (b) an alternative reinforcer (e.g., toys in the attention condition of a functional analysis). Next, we taught the participants to request each reinforcer in the presence of a different discriminative stimulus (SD). Then, we evaluated the effects of differential reinforcement of communication (DRC) using the functional and alternative reinforcers and correlated SDs, with and without extinction of destructive behavior. During all applications, DRC (in combination with SDs that signaled available reinforcers) rapidly reduced destructive behavior to low levels regardless of whether the functional reinforcer or an alternative reinforcer was available or whether reinforcement for destructive behavior was discontinued (i.e., extinction).

Adolescent↗

PubMed1997

The structural organization of connections between hypothalamus and cerebral cortex.

Motivated behavior requires coordinated somatic, autonomic, and endocrine responses, and may be divided into initiation, procurement, and consummatory phases (Swanson, L.W. and Mogenson, G.J., Neural mechanisms for the functional coupling of autonomic, endocrine and somatomotor responses in adaptative behavior, Brain Res. Rev., 3 (1981) 1-34). Obviously, such behavior may involve the entire central nervous system, although it is important to identify circuitry or systems that mediate the behavior directed toward specific goal objects. This problem has recently been clarified by the identification of hypothalamic subsystems important for the execution of instinctive behaviors related to ingestion, reproduction, and defense. These subsystems are modulated by sensory (reflex), central control (e.g., circadian), and voluntary (cortical) inputs. The latter are dominated by inputs from the ventral temporal lobe and medial prefrontal region, which are both direct and via associated parts of the basal nuclei (ganglia). Hypothalamic output is characterized by descending projections to brainstem and spinal motor systems, and by projections back to the cerebral cortex, which are both direct and via a continuous rostromedial part of the dorsal thalamus. This thalamic region includes the anterior, medial, and midline groups, which in turn innervate a continuous ring of cortex that includes the hippocampal formation and the cingulate, prefrontal, and insular regions. Parts of this thalamic region also innervate the ventral striatum, which receives a massive input from the cortical rings as well.

Animals↗

PubMed1997

Database challenges and solutions in neuroscientific applications.

In the scientific community, the quality and progress of various endeavors depend in part on the ability of researchers to share and exchange large quantities of heterogeneous data with one another efficiently. This requires controlled sharing and exchange of information among autonomous, distributed, and heterogeneous databases. In this paper, we focus on a neuroscience application, Neuroanatomical Rat Brain Viewer (NeuART Viewer) to demonstrate alternative database concepts that allow neuroscientists to manage and exchange data. Requirements for the NeuART application, in combination with an underlying network-aware database, are described at a conceptual level. Emphasis is placed on functionality from the user's perspective and on requirements that the database must fulfill. The most important functionality required by neuroscientists is the ability to construct brain models using information from different repositories. To accomplish such a task, users need to browse remote and local sources and summaries of data and capture relevant information to be used in building and extending the brain models. Other functionalities are also required, including posing queries related to brain models, augmenting and customizing brain models, and sharing brain models in a collaborative environment. An extensible object-oriented data model is presented to capture the many data types expected in this application. After presenting conceptual level design issues, we describe several known database solutions that support these requirements and discuss requirements that demand further research. Data integration for heterogeneous databases is discussed in terms of reducing or eliminating semantic heterogeneity when translations are made from one system to another. Performance enhancement mechanisms such as materialized views and spatial indexing for three-dimensional objects are explained and evaluated in the context of browsing, incorporating, and sharing. Policies for providing the system with fault tolerance and avoiding possible intellectual property abuses are presented. Finally, two existing systems are evaluated and compared using the identified requirements.

Animals↗

PubMed1997

On the relation of mands and the function of destructive behavior.

When standard analogue functional analysis procedures produce inconclusive results in children with conversational speech, the child's mands may help to identify the function of destructive behavior. In the current investigation, functional analyses conducted with 2 children who exhibited self-injury, aggression, and property destruction were undifferentiated across conditions. Based on informal observations and school and parental report, an analysis was conducted using mands to help determine the function of the destructive behavior. Using a multielement design, the therapist's compliance with the child's mands occurred either on a fixed-ratio (FR) 1 schedule or contingent on destructive behavior. Destructive behavior occurred at high and consistent levels when reinforcement of mands was contingent on destructive behavior and at near-zero levels when reinforcement of mands occurred on the FR 1 schedule. Based on these results, a second analysis was conducted in which compliance to mands occurred only when the child appropriately requested it (i.e., functional communication training plus extinction) and, for 1 child, compliance with mands was terminated contingent upon destructive behavior (i.e., functional communication training plus response cost). For both children, the rates of destructive behavior decreased markedly. The results suggest that assessing the child's mands may be useful in decreasing destructive behavior when a functional analysis is inconclusive.

Adolescent↗

PubMed1997

Toward the development of structured criteria for interpretation of functional analysis data.

Using functional analysis results to prescribe treatments is the preferred method for developing behavioral interventions. Little is known, however, about the reliability and validity of visual inspection for the interpretation of functional analysis data. The purpose of this investigation was to develop a set of structured criteria for visual inspection of multielement functional analyses that, when applied correctly, would increase interrater agreement and agreement with interpretations reached by expert consensus. In Study 1, 3 predoctoral interns interpreted functional analysis graphs, and interrater agreement was low (M = .46). In Study 2, 64 functional analysis graphs were interpreted by a panel of experts, and then a set of structured criteria were developed that yielded interpretive results similar to those of the panel (exact agreement = .94). In Study 3, the 3 predoctoral interns from Study 1 were trained to use the structured criteria, and the mean interrater agreement coefficient increased to .81. The results suggest that (a) the interpretation of functional analysis data may be less reliable than is generally assumed, (b) decision-making rules used by experts in the interpretation of functional analysis data can be operationalized, and (c) individuals can be trained to apply these rules accurately to increase interrater agreement. Potential uses of the criteria are discussed.

Humans↗

PubMed1997

On the relative reinforcing effects of choice and differential consequences.

Research on the reinforcing effects of providing choice-making opportunities to individuals with developmental disabilities (i.e., allowing them to choose reinforcers or tasks) has produced inconsistent results, perhaps because the mechanisms underlying such effects remain unclear. Choice may produce a reinforcement effect because it is correlated with differential consequences (i.e., choice may increase one's access to higher preference stimuli), or it may have reinforcement value independent of (or in addition to) the chosen stimulus. In Experiment 1, we used a concurrent-operants arrangement to assess preference for a choice condition (in which participants selected one of two available reinforcers) relative to a no-choice condition (in which the therapist selected the same reinforcers on a yoked schedule). All 3 participants preferred the choice option. In Experiment 2, we altered the schedules so that the participant selected one of two lower preference reinforcers in the choice condition, whereas the therapist selected a higher preference stimulus for the participant either half or all of the time in the no-choice condition. Participants typically allowed the therapist to select reinforcers for them (i.e., they allocated responding to the no-choice condition) when it resulted in greater access to higher preference stimuli.

Adolescent↗

PubMed1996

Organization of projections from the dorsomedial nucleus of the hypothalamus: a PHA-L study in the rat.

The axonal projections of the dorsomedial nucleus of the hypothalamus were investigated by using Phaseolous vulgaris-leucoagglutinin. The main conclusion of this work is that these projections are largely intrahypothalamic, with smaller components directed toward the brainstem and telencephalon. Although the intrahypothalamic pathways are very complex and intermix at various levels, we conclude that dorsomedial nucleus outputs follow three distinct ascending pathways: periventricular, coursing through the hypothalamic periventricular zone; ventral, traveling beneath the medial zone; and lateral, ascending in medial parts of the lateral hypothalamic area. Within the hypothalamus, the most densely innervated areas are the paraventricular nucleus, other dorsal regions of the periventricular zone, the preoptic suprachiasmatic nucleus, and the parastrial nucleus. Other significant terminal fields include the median preoptic, anteroventral periventricular, lateral part of the medial preoptic, and anteroventral preoptic nuclei; and the retrochiasmatic (including perisuprachiasmatic) area. Descending projections follow two pathways that also converge at various levels: a dorsal pathway in the midbrain periventricular system travels through, and primarily innervates, the periaqueductal and pontine gray, and a ventral pathway extends through ventromedial regions of the brainstem. Although sparse, fibers in the later pathway can be traced as far caudally as the nucleus of the solitary tract. The results are discussed relative to the pathways and properties of nearby hypothalamic medial zone nuclei. Dorsomedial nucleus projections are similar to certain other nuclei (e.g., anteroventral periventricular and parastrial) with predominantly intrahypothalamic projections, and different from those arising in the medial zone nuclei (medial preoptic, anterior hypothalamic, ventromedial, and mammillary.

Afferent Pathways↗