Microcomputer-based programmed instruction in identity matching to sample for persons with severe disabilities

Three individuals with mental retardation, who had failed to learn identity matching to sample with standard fading and prompting procedures, were given microcomputer-based programmed instruction. The methods were based on an analysis of two features of typical identity matching procedures: (a) within each trial, the current sample stimulus must control comparison selection, and (b) across trials, specific comparison stimuli must function both as S+ and as S–, depending upon the sample presented (conditional discrimination). During the first phase of training, one-trial acquisition of discriminative stimulus control was established in a nonconditional discrimination context where the S+ or S– functions of specific stimuli did not change from trial to trial. After one-trial learning was established, conditional discrimination was programmed by gradually introducing reversals of S+/S– stimulus functions. All three participants learned to perform conditional identity matching. Avenues for further analysis of the prerequisites for conditional discrimination and continued development of programmed methods are discussed.     

EXTINCTION OF SELF-INJURIOUS ESCAPE BEHAVIOR WITH AND WITHOUT INSTRUCTIONAL FADING

Three individuals with developmental disabilities participated in a study of the treatment of self-injurious behavior (SIB) maintained by negative reinforcement (escape from educational tasks). Treatment was implemented in a multiple baseline design across subjects, in which two treatments were compared in a multielement format. Both treatment conditions included an escape-extinction component in which SIB no longer produced escape. One of the conditions also included a fading component in which the frequency of instructions was initially reduced to zero and then was gradually faded back in across sessions until the instructional rate matched that of the original baseline. Results indicated that extinction alone reduced SIB to the end-of-treatment criterion in fewer sessions than did extinction plus fading for all 3 subjects. For 2 of the 3 subjects, however, there was an initial increase in the frequency of SIB at the outset of treatment with extinction (an extinction burst) that was not observed when extinction was combined with the fading component.     

ERRORLESS LEARNING: REINFORCEMENT CONTINGENCIES AND STIMULUS CONTROL TRANSFER IN DELAYED PROMPTING

Delayed prompting can produce errorless discrimination learning. There is inherent in the procedure a disparity in reinforcement density which favors unprompted over prompted responses. We used three schedules of reinforcement to investigate the impact of reinforcement probability on transfer of stimulus control. One schedule of reinforcement was equal prior to and following a prompt (CRF/CRF), the second favored unprompted responses (CRF/FR3), and the third favored responses following the prompt (FR3/CRF). Experimental questions concerned the probability of errors, the probability of transfer, and the rate of transfer in the context of delayed prompting. Transfer was accelerated when reinforcement probability favored anticipatory responding. The schedule that favored prompted responses did not prevent a shift to unprompted responding. Errors were infrequent across procedures. Reinforcement probability contributes to but does not entirely determine transfer of stimulus control from a delayed prompt.     

Fading and errorless transfer in successive discriminations

A successive discrimination between red positive and green negative stimuli was established with pigeon subjects. Then, lines with different angular orientations were superimposed on one of the colors to form compound stimuli. Finally, either the colored element of the positive compound, the colored element of the negative compound, or both colored elements together, were gradually attenuated. Before each attenuation, the line elements were presented alone against dark backgrounds as probes to assess the degree to which they had acquired control of responding. When the positive color was attenuated alone or in conjunction with the negative color, angular orientation acquired control of responding in an errorless fashion. Lines, however, did not acquire control when only the negative component was attenuated. These results were interpreted in terms of changes in the predictability of reinforcement by color and line elements during stimulus attenuation. Finally, attenuation of the negative stimulus influenced the number of “dimensions” of the new line stimuli that acquired control of responding. When the positive stimulus was attenuated with the negative, only one dimension of the lines acquired control. When the positive stimulus was attenuated without the negative, however, more than one dimension of the lines acquired control of responding. These results were interpreted in terms of how errorless performance can be maintained while an organism attends to different dimensions of the new stimuli.     

ENURESIS CONTROL THROUGH FADING,ESCAPE, AND AVOIDANCE TRAINING

A twin-signal device that provides both escape and avoidance conditioning in enuresis control is described involving a procedure documented by two case studies. In addition, a technique of fading as an adjunct to the process is utilized with one subject. The results indicate that a combination of operant and respondent conditioning involving escape and avoidance training may be an improvement over the more traditional conditioning procedure.     

Behavioral momentum and stimulus fading in the acquisition and maintenance of child compliance in the home

The provision of a series of requests to which compliance is highly likely (high-probability requests) immediately antecedent to low-probability requests has been used to establish behavioral momentum of compliance. We evaluated a fading procedure for maintaining high levels of compliance obtained with high-probability requests. Fading involved a systematic reduction in the number of high-probability requests and an increase in the latency between the high- and low-probability requests. High levels of compliance for both "do" and "don't" requests were maintained for 16 weeks in a 5-year-old boy with developmental disabilities after the high-probability request sequence was faded. Similar maintenance was obtained for "do" requests in a 15-year-old girl with developmental disabilities. For this subject, however, the high-probability request sequence was ineffective with "don't" requests. When "don't" requests were phrased as "do" requests, the high-probability request sequence produced high levels of compliance to the low-probability request. High levels of compliance to these "do" requests were maintained for 16 weeks after the high-probability request sequence was faded.     

Effects of delay fading and signals on self‐control choices by children

The current study is a systematic replication and extension of work by Schweitzer & Sulzer‐Azaroff (1988). The effects of delay fading alone and in combination with signals on choices between larger, delayed reinforcers and smaller, immediate reinforcers by four children with language deficits were examined. For one of the two children exposed to delay fading alone, larger reinforcers were selected at longer delays relative to the initial self‐control assessment. For all four children, the delay‐fading‐plus‐signal condition resulted in selection of larger reinforcers at considerably longer delays relative to the self‐control assessment.     

Establishing motion control in children with autism and intellectual disability: Applications for anatomical and functional MRI

Excessive motion makes magnetic resonance imaging (MRI) extremely challenging among children with autism spectrum disorder (ASD). The medical risks of sedation establish the need for behavioral interventions to promote motion control among children with ASD undergoing MRI scans. We present a series of experiments aimed at establishing both tolerance of the MRI environment and a level of motion control that would be compatible with a successful MRI. During Study 1, we evaluated the effects of prompting and contingent reinforcement on compliance with a sequence of successive approximations to an MRI using a mock MRI. During Study 2, we used prompting and progressive differential reinforcement of other behaviors (DRO) to promote motion control in a mock MRI for increasing periods of time. Finally, during Study 3, some of the participants underwent a real MRI scan while a detailed in‐session motion analysis informed the quality of the images captured.     

渐减提示法呈现样例对学习迁移的作用

本研究探讨了从样例学习到问题解决过渡的样例设计方式。实验结果表明：渐减提示法是动态的联结样例和问题解决的有效形式,符合认知技能获得的四阶段模型和建构主义学习观的基本要求;渐减提示法可以促进学习者对样例问题进行高质量的自我解释和产生心理预期,是实现从样例学习到问题解决过渡的有效方法。     

An evaluation of differential reinforcement with stimulus fading as an intervention for medical compliance

Individuals with autism spectrum disorder (ASD) often exhibit noncompliance during medical exams. One intervention used to address this concern is differential reinforcement. Although differential reinforcement includes extinction, it may not be feasible or safe to implement extinction during medical exams. In the current study, we evaluated differential reinforcement without extinction and differential reinforcement without extinction plus stimulus fading, for increasing compliance during routine medical exams exhibited by 4 individuals with ASD. An indirect assessment identified problematic medical procedures, and a functional analysis showed that participants' disruptive behavior was maintained by escape from medical tasks. Differential reinforcement without extinction was insufficient in increasing medical compliance with 3 of 4 participants. The addition of a modified stimulus fading procedure that involved gradually introducing smaller components of problematic exam steps was effective in increasing medical compliance with all exam steps.