Buscador de artigos científicos

We tested the effectiveness of a tablet application and differential reinforcement to increase eye contact in 3 children with autism. The application required the child to look at a picture of a person's face and identify the number displayed in the person's eyes. Eye contact was assessed immediately after training, 1 hr after training, and in a playroom. The tablet application was not effective; however, differential reinforcement was effective for all participants.

With four children with autism we evaluated a refinement to time‐based reinforcement designed to reduce response persistence when we simultaneously introduced time‐based reinforcement and extinction. We further evaluated whether this refinement mitigated response recurrence when all reinforcer deliveries ceased during an extinction‐only disruptor phase. The refinement involved increasing the saliency of the contingency change from contingent reinforcement (during baseline) to time‐based reinforcement by delivering different colored reinforcers during time‐based reinforcement. Behavioral momentum theory predicts that increasing the discriminability of the change from variable‐interval to variable‐time reinforcement should lead to faster reductions in responding. We present data on four participants, three of whom displayed response patterns consistent with the predictions of behavioral momentum theory during time‐based reinforcement. However, the participants showed more varied patterns of recurrent behavior during extinction. We discuss these results within a translational research framework focusing on strategies used to mitigate treatment relapse for severe destructive behavior, as time‐based reinforcement is one of the most commonly prescribed interventions for destructive behavior displayed by individuals with intellectual and developmental disabilities.

We compared the effects of Lag 0 and Lag 1 schedules of reinforcement on children's responses naming category items in a group context and subsequent responses emitted during individual testing in which the schedule of reinforcement remained Lag 0. Specifically, we measured response variability and novel responses to categories for 3 children who demonstrated the lowest level of variability during an initial individual Lag 0 testing session. An additional 3 children who emitted a high level of variability during initial individual Lag 0 testing sessions served as peers during group sessions. Results showed that participants conformed to the Lag 1 schedule and were more likely to repeat peer responses in the group and during individual testing in the Lag 1 condition. Furthermore, the reinforcement schedule in effect during group sessions affected participants’ varied responses during individual testing, during which the reinforcement schedule remained unchanged.

Many studies have shown that (a) functional communication training ( FCT ) is effective for reducing problem behavior, and (b) multiple schedules can facilitate reinforcer schedule thinning during FCT . Most studies tha have used multiple schedules with FCT have included therapist‐arranged stimuli (e.g., colored cards) as the discriminative stimuli ( S D s ), but recently, researchers have evaluated similar multiple‐schedule training procedures with naturally occurring S D s (e.g., overt therapist behavior). The purposes of the current study were to compare the effects of arranged and naturally occurring S D s directly during (a) acquisition of discriminated functional communication responses ( FCRs ) and (b) generalization of discriminated FCRs when we introduced the multiple schedules in novel contexts in which the naturally occurring stimuli were either relatively easy or difficult to discriminate. Results showed that (a) 2 of 3 participants acquired discriminated responding of the FCR more rapidly with arranged than with naturally occurring stimuli, (b) 2 of 3 participants showed resurgence of problem behavior , and (c) 2 of 3 participants showed greater generalization of discriminated responding to novel contexts with arranged stimuli than with naturally occurring stimuli. We discuss these results relative to the conditions under which naturally occurring and arranged S D s may promote rapid and generalized treatment gains.

This study compared 2 methods of fading prompts while teaching tacts to 3 individuals who had been diagnosed with autism spectrum disorder ( ASD ). The 1st method involved use of an echoic prompt and prompt fading. The 2nd method involved providing multiple‐alternative answers and fading by increasing the difficulty of the discrimination. An adapted alternating‐treatments design showed that both procedures were more effective than a no‐intervention control condition. Providing multiple alternatives did not increase error rates or teaching time, and better maintenance was shown for tacts taught with the multiple‐alternative prompt.

Prior research shows that learners have idiosyncratic responses to error‐correction procedures during instruction. Thus, assessments that identify error‐correction strategies to include in instruction can aid practitioners in selecting individualized, efficacious, and efficient interventions. The current investigation conducted an assessment to compare 5 error‐correction procedures that have been evaluated in the extant literature and are common in instructional practice for children with autism spectrum disorder ( ASD ). Results showed that the assessment identified efficacious and efficient error‐correction procedures for all participants, and 1 procedure was efficient for 4 of the 5 participants. To examine the social validity of error‐correction procedures, participants selected among efficacious and efficient interventions in a concurrent‐chains assessment. We discuss the results in relation to prior research on error‐correction procedures and current instructional practices for learners with ASD .

Responding by exclusion is a type of emergent repertoire in which an individual chooses an alternative by the apparent exclusion of other available alternatives. In this case it is possible to respond appropriately to an undefined stimulus (one that has not previously acquired discriminative functions) by excluding the defined alternatives. There is evidence of exclusion in humans and nonhuman animals, although learning as an outcome of exclusion does not always occur. This study aimed to investigate exclusion in visual simple discriminations and learning of new simple discriminations resulting from exclusion in four border collies. Subjects were trained to perform simple simultaneous discriminations between pairs of tridimensional objects, and were then tested for exclusion, novelty control and learning of new simple discriminations. All dogs successfully responded by exclusion, choosing an undefined stimulus displayed with an S‐. For three dogs, it was possible to conclude that these previously undefined stimuli acquired S+ functions, documenting learning of new simple discriminations. However, this required up to four exposures to exclusion trials with each pair of stimuli.

The ability of organisms to detect reinforcer‐rate changes in choice preparations is positively related to two factors: the magnitude of the change in rate and the frequency with which rates change. Gallistel (2012) suggested similar rate‐detection processes are responsible for decreases in responding during operant extinction. Although effects of magnitude of change in reinforcer rate on resistance to extinction are well known (e.g., the partial‐reinforcement‐extinction effect), effects of frequency of changes in rate prior to extinction are unknown. Thus, the present experiments examined whether frequency of changes in baseline reinforcer rates impacts resistance to extinction. Pigeons pecked keys for variable‐interval food under conditions where reinforcer rates were stable and where they changed within and between sessions. Overall reinforcer rates between conditions were controlled. In Experiment 1, resistance to extinction was lower following exposure to dynamic reinforcement schedules than to static schedules. Experiment 2 showed that resistance to presession feeding, a disruptor that should not involve change‐detection processes, was unaffected by baseline‐schedule dynamics. These findings are consistent with the suggestion that change detection contributes to extinction. We discuss implications of change‐detection processes for extinction of simple and discriminated operant behavior and relate these processes to the behavioral‐momentum based approach to understanding extinction.

Two principal goals of functional communication training (FCT) are (a) to eliminate destructive behavior and (b) to establish a more acceptable, yet functionally equivalent, communication response (FCR). A related and critically important goal is to thin the schedule of reinforcement for the FCR to levels that can be reasonably managed by caregivers. Researchers have described several approaches to thinning FCT reinforcement schedules. We summarize the results of 25 consecutive applications (among 20 cases) in which schedule‐thinning procedures employed discriminative stimuli to signal when the FCR would and would not produce reinforcement (i.e., using multiple schedules, response restriction, or chained schedules). Results suggest that schedule‐thinning procedures that use discriminative stimuli can maintain the effectiveness of FCT while they minimize the need for punishment or other supplemental procedures.

We evaluated the effects of a parent‐implemented intervention to teach yoga poses to 3 children with developmental delays. Graduated guidance, provided by the participants' mothers, was introduced in a multiple baseline design across the participants. With the introduction of intervention, imitation of the response chains increased over baseline for all participants. Generalization to novel and live models occurred for 2 participants. Results are discussed in terms of using behavior‐analytic procedures to teach physical fitness activities to individuals with developmental disabilities.