Teaching autistic children to use extra-stimulus prompts

Autistic children often do not transfer from extra-stimulus prompts, and thus do not utilize a frequent learning aid. It has been hypothesized that this is due to stimulus overselectivity; a failure to respond to simultaneous multiple cues. This study was designed to determine if autistic children who initially respond only to single cues can be taught a set to respond to two cues and subsequently utilize an extra-stimulus (pointing) prompt. Four autistic children were pretested to determine if they could learn a complex visual discrimination by either trial and error or an extra-stimulus prompt fading procedure. Since they did not, the children were then taught to respond to two cues through a multiple-cue training procedure and subsequently tested to determine if they could now utilize a pointing prompt. Results indicated that while all four children initially did not transfer from an extra-stimulus (pointing) prompt, they did so subsequent to multiple-cue training. The results are discussed in terms of implications for treatment (remediating overselectivity) and in relation to normal child development.     

Selective responding to the components of multiple visual cues by autistic children

Fifteen autistic and 15 normal Ss were trained to respond to a card containing two visual cues. After this training disctimination was established, the children were tested on the single cues in order to assess whether one or both stimuli had acquired control over their responding. The autistic children (12 of 15) gave evidence for stimulus overselectivity in that they responded correctly to only one of the two component cues. On the other hand, the normal children (12 of 15) showed clear evidence of control by both component cues of the training card. These results were consistent with previous studies, where autistics showed overselectivity when presented with multiple sensory input in several modalities. However, now autistic children appear to have difficulty responding to multiple cues even when both cues are in the same modality. These results were discussed in relation to the experimental literature on selective attention in normally functioning organisms.     

EFFECTS OF WITHIN-STIMULUS AND EXTRA-STIMULUS PROMPTING ON DISCRIMINATION LEARNING IN AUTISTIC CHILDREN1

Two different prompting procedures to teach visual and auditory discriminations to autistic children were compared. The first involved presenting an added cue as an extra-stimulus prompt. This required the child to respond to both prompt and training stimulus. The second involved the use of a within-stimulus prompt. This consisted of an exaggeration of the relevant component of the training stimulus and thus did not require that the child respond to multiple cues. The results indicated that (1) children usually failed to learn the discriminations without a prompt, (2) children always failed to learn when the extra-stimulus prompt was employed but usually did learn with the withinstimulus prompt, and (3) these findings were independent of which modality (auditory or visual) was required for the discrimination.     

S+ versus S− Fading in prompting procedures with autistic children

The purpose of this investigation was to assess the relative effectiveness of two prompt-fading procedures for teaching difficult visual discriminations to autistic children. Both prompt procedures involved within-stimulus fading where manipulation occurred on the relevant component of the discrimination. One procedure involved fading first along the S+ stimulus, while holding the S? stimulus constant. The other procedure involved fading first along the S? stimulus, while holding the S+ stimulus constant. Eight autistic children were each taught two discriminations, one by each of the prompt procedures. Results indicated that for all but one child, the discriminations were acquired significantly faster, with fewer errors, when the S+ stimulus was faded first. These findings are related to the literature on the effects of stimulus novelty on selection and learning.     

Some detrimental effects of using extra stimuli to guide learning in normal and autistic children

This study was designed to assess the effectiveness of using prompts (extra "guiding" stimuli) for teaching normal and autistic children. One group of normal children was pretrained on a color discrimination. Later, the colors were used as prompts (presented simultaneously with new training stimuli) to teach four new discriminations. Another group of normal children was trained on the same discriminations with a trial-and-error procedure (i.e., no prompting). A third group consisted of autistic children who were trained on these discriminations using the prompt procedure. Analyses of the results showed the following. (1) The trial-and-error group of normal children acquired more discriminations than the prompt group of normal children. (2) A comparison of the two prompt groups showed that the autistics failed to transfer from the prompt cue to the training cue more often than the normal children; rather, the autistics generally continued responding to the faded color cue. (3) Autistic and normal children who failed to acquire the discriminations when trained with a prompt procedure did acquire these discriminations when no prompt was used. That is, the results suggest that the presentation of an extra guiding stimulus was detrimental to the acquisition of training discriminations for all subjects, and particularly so far autistic children. Therefore, the common practice of providing extra guiding stimuli in proportion to the severity of the learning disorder may actually be harmful to the learning of new skills. Implications of these results for future research are discussed.     

Reversal and nonreversal shifts in autistic children

Reversal and nonreversal shifts in nineteen 2- to 14-year-old autistic children were studied. Each child was taught both a reversal and nonreversal shift discrimination task. The reversal shift condition entailed teaching the child to respond to one (the S+) of a pair of stimuli during training and subsequently reversing the S+ during testing. The nonreversal shift condition consisted of teaching the child two unrelated discriminations during training and testing. The results indicated that the older autistic children did better on reversal shifts than younger children who did better on nonreversal shifts. These findings are consistent with those for normal children.     

Comparing autistic and normal children along the dimensions of reinforcement maximization, stimulus sampling, and responsiveness to extinction

The purpose of this study was to assess autistic children's ability to maximize reinforcement, sample among available stimuli, and respond to extinction. Responding to five concurrent reinforcement schedules (CRF, FR 2, FR 4, FR 7, and FR 11) was monitored and compared to groups of mental age-matched and chronological age-matched normal children. When a given child consistently selected a given schedule of reinforcement, it was then put on extinction, and both perseveration and responding to the remaining (intact) schedules of reinforcement were monitored. The results showed, first, that while normal children selected the richest schedule of reinforcement, autistics did not maximize reinforcement, typically selecting one of the thinner schedules available. Second, the autistic children sampled less, and less efficiently, than the normal children. Third, the autistic children proved to be much less responsive to extinction, perseverating longer than the normal children before switching to a new reinforcement schedule. Fourth, whenever extinction proved to be a problem in the autistics, it was quickly achieved by a simple change in the stimulus conditions. These results are discussed as possible "keystone" deficits, which may be causally related to many of the behavioral deficits of autism and which might be important target behaviors for treatment.     

Transfer and Counterconditioning of Conditional Control in the Rabbit Nictitating Membrane Response

Two experiments using the rabbit nictitating membrane response investigated whether training in one conditional discrimination (A X+, B X-), enabled the feature cues (A and B) to modulate responding to another CS (Y) trained as a target stimulus in a second conditional discrimination (C Y+, D Y-). There was near-complete transfer of the feature cue's conditional control, indicating that the feature cue's ability to modulate responding is not based on an association specific to the training target. Experiment 2 also revealed that the role of a stimulus to act as a conditional cue is affected by its ability to act as a simple conditioned excitor or inhibitor. Following initial acquisition of two conditional discriminations, two feature cues were reinforced in a pattern consistent with the initial conditional discrimination (A +, B-), whereas the other two feature cues were reinforced in the reverse pattern to that of the original conditional discrimination (C-, D +). Subsequent tests revealed that the reversed training of the feature cues interfered with the original conditional discriminations. The results are consistent with theories that the feature cue gains an association with a representation of the emotional attributes of the US, which acts to modulate responding to the target stimulus through a diffuse change in motivational level. However, hierarchical theories of conditional discriminations that assume a lack of CS-specificity may also be able to explain the findings.     

Resurgence of derived stimulus relations.

Resurgence has been shown in human and nonhuman operant behavior, but not in derived relational responses. The present study examined this issue. Twenty-three undergraduates were trained to make conditional discriminations in a three-choice matching-to-sample paradigm. The training resulted in three equivalence classes, each consisting of four arbitrarily configured visual stimuli. The same 12 stimuli were then reorganized, and the conditional discrimination training was repeated such that three new classes were possible. In a subsequent test of derived relations, most subjects showed response patterns that were consistent with the altered conditional discriminations. Subjects were then exposed to conditional discrimination trials under extinction. Most subjects continued to respond consistently with the most recently reinforced conditional discrimination trials. During the next phase, subjects were exposed to symmetry and equivalence trials. Responses consistent with the most recent training produced feedback saying that the responses were incorrect, whereas other responses produced no feedback. Most subjects showed a resurgence of responding that was consistent with their earlier training. Finally, subjects were exposed to conditional discrimination trials carried out in extinction. Most subjects continued to show a resurgence of responding that was consistent with their early training.     

Overselectivity,developmental level,and overtraining in autistic and normal children

Thirteen autistic children were compared to 13 normal children, matched to them in mental age, on performance of a visual discrimination task. Form, color, and size were relevant and redundant cues. The groups did not differ significantly in mean trials to reach criterion or in breadth of learning, and both groups increased their breadth of learning after 50 trials of overtraining. Form was preferred to color and size by both autistic and normal children. Within each group, rank on mental age was highly correlated with rank in breadth of learning. Verbal and nonverbal autistic children did not differ in breadth of learning or in dimensional preference. Even nonverbal autistics equaled the performance of their normal controls. Our results suggest that overselective attention is better understood as part of a general developmental lag in cognition in autistic children than as a specific deficit underlying psychotic behavior.This research was supported in part by NIMH Grant 11440, O. I. Lovaas, principal investigator. The authors thank Dr. Lovaas and Dennis C. Russo for their helpful criticisms of an earlier draft.     

Auditory overselectivity in autistic children

Autistic and normal children were trained to respond to a complex stimulus containing two auditory components. After the discrimination was acquired, the individual components were presented separately, allowing assessment of the extent to which the child's responding was controlled by one or both of the cues. The autistic children, unlike the normal children, provided evidence for stimulus overselectivity in that 6 of 8 autistic subjects responded to only one of the components. These results are consistent with those of previous studies which showed that when autistic children are presented with a complex visual or multiple-modality stimulus, they selectively respond to only one component of the complex. The present results extend the stimulus overselectivity hypothesis to the situation where all of the stimuli occur within the auditory modality. It is suggested that auditory overselectivity may partially account for autistic deficits in speech comprehension.     

The generality of overselectivity in developmentally disabled children

A growing body of research suggests that low Mental Age (MA) autistic and retarded children show a unique stimulus control deficit, one that may cause many or most of their behavioral deficiencies. This problem, stimulus overselectivity, is evidenced when a child responds only to a restricted portion of the stimulus environment when compared with normal children. The purpose of this study was to assess whether this overselectivity is general across situations or whether it is restricted to certain stimulus/task conditions. Eight autistic children, who evidenced overselectivity on a preassessment task, and 8 normal children with similar MA levels participated. All children were trained on 3 tasks to determine if overselectivity varied as a function of different stimulus conditions. Each of the 3 tasks involved training a child to respond to (i.e., touch) a card containing a circle (S +) and to avoid a blank (S ?) card. In each case, the circle comprised a series of dots. The difference between the 3 circles (tasks) was the distance between the successive dots making up each circle. Also, in the minimal separation condition the dots were smaller in size and greater in number than in the larger separation conditions. Of concern was whether autistic children learned about the gestalt (i.e., the circle), which required attention to multiple cues, or whether children would overselect and respond to the dots. The results showed that (1) stimulus overselectivity was found not to be a generalized deficit in autistic subjects; instead, it varied as a function of the stimulus variables; and (2) the stimulus variables manipulated in this study similarly influenced the responding of both normal and autistic children. The implications of these data for a theory of overselectivity are discussed.     

THE ROLE OF RESPONSE DELAY IN IMPROVING THE DISCRIMINATION PERFORMANCE OF AUTISTIC CHILDREN

This study investigated the influence of a response delay requirement on the discrimination performance of autistic children. In the context of a multiple baseline design with subsequent repeated reversals, two conditions were compared: a no-response-delay condition, where the child was allowed to make the target response immediately after presentation of the discriminative stimulus versus a response-delay condition, where the target response was permitted three seconds following the discriminative stimulus when the therapist would signal the child to respond. The results showed that the response-delay condition produced higher levels of correct responding than the no-response-delay condition. In addition, teachers in the research setting rated the response-delay procedure to be a practical and effective teaching technique that could be implemented in a classroom setting. The results were discussed in relation to the literature on impulsivity, and were interpreted as indicating that the response-delay procedure provides a valuable technique for teaching autistic children.     

Conditional discrimination in mentally retarded adults: the development of generalized skills.

The development of generalized conditional discrimination skills was examined in adults with retardation. Two subjects with histories of failure to acquire arbitrary matching under trial-and-error procedures were successful under procedures that trained one or more prerequisite skills. The successive discrimination between the sample stimuli was established by training the subjects to name the stimuli. The simultaneous discrimination between the comparison stimuli was established using either (a) standard simple discrimination training with reversals or (b) a procedure in which each of the two sample-comparison relations in the conditional discrimination was presented in blocks of trials, with the size of the blocks decreasing gradually until sample presentation was randomized. The amount of prerequisite training required varied across subjects and across successive conditional discriminations. After acquiring either two or three conditional discriminations with component training, both subjects learned new conditional discriminations under trial-and-error procedures. In general, each successive conditional discrimination was acquired more rapidly. Tests showed that conditional responding had become a generalized skill. Symmetry was shown for almost all trained relations. Symmetry trial samples were ultimately named the same as the stimuli to which they were related in training.     

A relational differential outcomes effect: pigeons can classify outcomes as “good” and “better”

In a conditional discrimination each of two sample stimuli indicates which of two comparison stimuli is correct. When correct choice following each conditional stimulus is followed by a different outcome (one kind of food following one, a different kind of food following the other) it often facilitates acquisition and improves memory. In transfer designs, in which two different conditional discriminations are followed by the same two differential outcomes, outcome expectation can be shown to be sufficient for comparison choice. That is, the samples from one conditional discrimination are matched to comparisons from the other conditional discrimination based on the common outcomes alone. In the present study we asked if for pigeons the relative value of the differential outcomes (higher versus lower value) can serve as the basis for comparison choice, independent of other characteristics of the outcomes and of differential sample responding. That is, would different outcomes that could be described as “good” and “better” form two stimulus classes. For one conditional discrimination, the differential outcomes involved differential probability of reinforcement for choice of the correct comparison stimulus (0.80 vs. 0.20 for correct choice of the two comparisons, respectively). For the other conditional discrimination, the differential outcomes involved differential responding to the two comparison stimuli (5 pecks vs. 20 pecks to the correct comparisons, respectively). On test trials, when conditional stimuli from the two conditional discriminations were interchanged and the relative value of the differential outcomes could serve as the only basis for comparison choice, we found positive transfer. The results indicate that relational attributes of outcomes can serve as effective cues for comparison choice.     

Stimulus overselectiv1ty of autistic children in a two stimulus situation

Autistic and normal children were trained to respond to a complex stimulus involving an auditory component (white noise) and a visual component (red floodlight). After the Ss had acquired this discrimination, the individual components were presented singly to assess their control over the Ss' behavior. The autistic Ss' unlike the normals, demonstrated stimulus overselectivity in that seven out of nine Ss responded to only one of the components. These results were consistent with those of a previous study where autistics showed stimulus overselectivity in an experiment involving three modalities. In both experiments, the previously non-functional stimulus was made functional when trained separately.     

Conditional discrimination of series containing either two or three rewarded trials

Series of trials differing only in the number of rewarded trials (2R or 3R series) were used to test rats' ability to learn conditional numerical discriminations. Although the series were conditionally related to initially non-numerical situations, the rats successfully learned the discrimination. It is concluded that these discriminations can plausibly be conceptualized as conditional counting. A pair of transfer tests given after the discriminations were well established suggested that, under these conditions, numerical information will overshadow other non-numerical sources of discrimination made relevant by the transfer shifts.     

Reducing stimulus overselectivity in autistic children

It has been repeatedly reported that when presented with a discrimination task involving multiple cues, autistic children, as compared to normal children, tend to respond on the basis of only a restricted portion of the component cues. This phenomenon has been called stimulus overselectivity and has been implicated as a possible basis for some of the pronounced behavioral deficits characteristic of autism. Examination of the results of several previous studies suggests that the overselectivity effect might be reduced with repeated exposure to testing. However, since the previous studies were not designed to test this hypothesis, no conclusions were drawn regarding variables influencing the reduction of the overselectivity phenomenon. The present investigation was therefore conducted to determine if stimulus overselectivity in autistic children is changed as a function of repeated exposure to testing. Nineteen autistic children were trained on a discrimination task with a cue complex composed of two visual cues. After the children reached criterion on the task, they were exposed to a testing phase with probe trials where the cue components were presented singly. The results indicated that 16 of the children initially showed overselectivity and 3 responded to both cues. Of the 16 children who showed overselectivity, 13 decreased their level of overselectivity with continued testing. These results are discussed in relation to variables in the testing procedure itself and to the literature on selective attention.This research was funded by USPHS Research Grants MH11440, MH28210, and MH28231 from the National Institute of Mental Health. The authors wish to acknowledge the assistance of Cathy Hook, Hannelore Wilhelm, and Jon Killion in conducting this research.     

Autoshaping of abnormal children

Three experimentally naive abnormal children were exposed to a terminal operant contingency, i.e., reinforcement was delivered only if the children pressed a panel during intervals when it was lighted. Despite the absence of both successive approximation and manual shaping, it was found that each child began to respond discriminatively within a small number of trials. These data replicated previous animal studies concerned with the phenomena of autoshaping and signal-controlled responding. It was also found, however, that one type of autoshaping, the classical conditioning procedure, had a powerful suppressive effect on discriminative responding. An experimental analysis that consisted of a combination of intrasubject reversal and multiple baseline designs established the internal validity of the findings. The finding of rapid acquisiton of signalcontrolled responding obtained with the initial procedure is suggested to have practical significance. The disruptive effects of the classical form of autoshaping are discussed in terms of negative behavioral contrast.Funding for this study and for the development of the computer-operated laboratory was provided by the USOE, Bureau of Education for the Handicapped, as a portion of Grant Number G007604305, sensory discrimination, generalization, and language training of autistic children, awarded to R. L. Blanton and C. W. Deckner. The authors would like to express their appreciation to John Halsell for his assistance in computer operations and data collection.     

Modification of slot-machine preferences through the use of a conditional discrimination paradigm

The present experiment investigated the impact of contextually trained discriminations on gambling behavior. Nine recreational slot-machine players were initially exposed to concurrently available computerized slot machines that were each programmed on random-ratio schedules of reinforcement and differed only in color. All participants distributed responding equally across the two slot machines. A conditional discrimination procedure was then used to teach the contextual cues representing the arbitrary relations of "greater than" and "less than." Following contextual cue training, participants were reexposed to the concurrent slot-machine task. After training of the contextual cues, a higher proportion of responses were made to the slot machine that shared formal properties (i.e., color) with the contextual cue representing "greater than."