A comparison of methods for teaching receptive labeling to children with autism spectrum disorders

Many early intervention curricular manuals recommend teaching auditory-visual conditional discriminations (i.e., receptive labeling) using the simple-conditional method in which component simple discriminations are taught in isolation and in the presence of a distracter stimulus before the learner is required to respond conditionally. Some have argued that this procedure might be susceptible to faulty stimulus control such as stimulus overselectivity (Green, 2001). Consequently, there has been a call for the use of alternative teaching procedures such as the conditional-only method, which involves conditional discrimination training from the onset of intervention. The purpose of the present study was to compare the simple-conditional and conditional-only methods for teaching receptive labeling to 3 young children diagnosed with autism spectrum disorders. The data indicated that the conditional-only method was a more reliable and efficient teaching procedure. In addition, several error patterns emerged during training using the simple-conditional method. The implications of the results with respect to current teaching practices in early intervention programs are discussed.     

A Comparison of Error-Correction Procedures Within Audio–Visual Conditional Discrimination Training

Children with autism spectrum disorders (ASD) often emit errors during the establishment of conditional discriminations. These children may not respond to more traditional error-correction procedures, such as least-to-most prompting. In this study, we compared two other types of error-correction procedures, namely embedding an identity-matching task as a differential observing response (DOR; Fisher et al. in J Appl Behav Anal 40:489–499, 2007) compared with a second-order fixed ratio 3/fixed ratio 1 (FR3 FR1) schedule with response cost procedure (Fisher et al. in J Appl Behav Anal 47:738–748, 2014). Results garnered from a multiple baseline design with embedded adapted alternating treatment design components demonstrated that the identity-matching/DOR procedure lead to superior acquisition of conditional discriminations for two boys with ASD. These findings suggest that for audio-conditional discrimination training, the identity-matching/DOR method may be more effective over the second-order FR3 FR1 with response cost approach.     

Establishing initial auditory‐visual conditional discriminations and emergence of initial tacts in young children with autism spectrum disorder

Children with autism spectrum disorder (ASD) often display impaired listener skills, and few studies have evaluated procedures for establishing initial auditory‐visual conditional discrimination skills. We developed and evaluated a treatment package for training initial auditory‐visual conditional discriminations based on the extant research on training such discriminations in children with ASD with at least some preexisting skills in this area. The treatment package included (a) conditional‐only training, (b) prompting the participant to echo the sample stimulus as a differential observing response, (c) prompting correct selection responses using an identity‐match prompt, (d) using progressively delayed prompts, and (e) repeating trials until the participant emitted an independent correct response. Results indicated all participants mastered all listener targets, and the two participants for whom we tested the emergence of corresponding tacts showed mastery of most tacts without direct training. We discuss these results relative to prior research on listener skills and tacts.     

A discrimination analysis of training-structure effects on stimulus equivalence outcomes.

Experiments designed to establish stimulus equivalence classes frequently produce differential outcomes that may be attributable to training structure, defined as the order and arrangement of baseline conditional discrimination training trials. Several possible explanations for these differences have been suggested. Here we develop a hypothesis based on an analysis of the simple simultaneous and successive discriminations embedded in conditional discrimination training and testing within each of the training structures that are typically used in stimulus equivalence experiments. Our analysis shows that only the comparison-as-node (many-to-one) structure presents all the simple discriminations in training that are subsequently required for consistently positive outcomes on all tests for the properties of equivalence. The sample-as-node (one-to-many) training structure does not present all the simple discriminations required for positive outcomes on either the symmetry or combined transitivity and symmetry (equivalence) tests. The linear-series training structure presents all the simple discriminations required for consistently positive outcomes on tests for symmetry, but not for symmetry and transitivity combined (equivalence) or transitivity alone. Further, the difference in the number of simple discriminations presented in comparison-as-node training versus the other training structures is larger when the intended class size is greater than three or the number of classes is larger than two. We discuss the relevance of this analysis to interpretations of stimulus equivalence research, as well as some methodological and theoretical implications.     

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.     

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.     

Common control by compound samples in conditional discriminations

We tested whether teaching control by single stimulus samples in conditional discriminations would result in common control of two-stimuli compound samples, and vice versa. In Experiment 1, 5 participants were first taught four single-sample conditional discriminations. The first conditional discrimination was as follows: given sample stimulus P1, select comparison stimulus A1 and not A2; given sample P2 select comparison A2 and not A1. The second conditional discrimination was as follows: given sample P1 select comparison B1 and not B2; given sample P2 select B2 and not B1. Different sample stimuli (Q1 and Q2) were used in the third and fourth conditional discriminations. Moreover, A1 and B1 were presented together as comparisons, such that, if Q1 was presented as the sample, A1 was correct and B1 was incorrect; and if Q2 was presented as the sample, B1 was correct and A1 was incorrect. A2 and B2 were also presented as comparisons. When Q1 was presented, A2 was correct and when Q2 was presented B2 was correct. After training with these four single stimulus sample discriminations, participants were tested with compound PQ samples presented with A1, A2, B1, and B2 as comparisons. If common control were established by the PQ stimuli, a participant would select A1 when P1Q1 was presented, A2 when P2Q1 was presented, B1 when P1Q2 was presented, and B2 when P2Q2 was presented. Such common control by PQ samples occurred in 4 of 5 participants. In Experiment 2, 4 participants were given reverse training. They were first taught to select the A1, A2, B1, and B2 stimuli in response to the appropriate PQ combinations and then probed on the single stimulus sample discriminations. All 4 participants were successful on this probe. Experiments 3 and 4 investigated the effects of teaching additional conditional discriminations with novel stimuli on subsequent transfer from the single-sample discriminations to performance on the compound-sample conditional discrimination.     

DERIVED MORE‐LESS RELATIONAL MANDS IN CHILDREN DIAGNOSED WITH AUTISM

In Experiment 1, more and less relations were trained for arbitrary Stimuli A1 and A2 with 3 children with autism. The following conditional discriminations were then trained: A1‐B1, A2‐B2, B1‐C1, B2‐C2. In subsequent tests, participants showed derived more‐less mands (mand with C1 for more and mand with C2 for less). A training procedure reversed the B‐C conditional discriminations, and participants then showed derived reversed more—less mands (mand with C1 for less, C2 for more). Baseline B‐C relations were retrained, and participants subsequently demonstrated a return to the original derived manding. A second experiment with 1 prior participant and 1 naive participant removed a possible confounding effect. Establishing derived manding may be an advantageous component when teaching a mand repertoire in applied settings.     

A comparison of blocked and mixed‐trial methods for teaching auditory–visual discriminations

Behavior analysts typically teach conditional discriminations in a mixed‐trial format but may switch to a blocked‐trial format for learners displaying limited acquisition. No known research has shown that mixed‐trial methods are more effective or efficient than blocked‐trial methods for teaching discriminations, so it is not clear why this format has been adopted as the “first‐line” intervention. We compared blocked and mixed‐trial formats for teaching novel auditory–visual discriminations to three adults with intellectual and developmental disabilities (IDD). Results show blocked‐trial methods resulted in faster skill acquisition in all cases, suggesting this format may be a preferable starting point for instruction.     

Auditory–Visual stimuli: Effects on derived relations with compound stimuli

This research explored the effect of teaching conditional discriminations with three procedures on the derivation of 36 stimuli relations (derived relations). The stimuli used consisted of three characteristics musical instruments, along with the corresponding picture. In the first experiment six university students were trained with simple stimuli and tested with compound auditory–visual samples; therefore, a one‐to‐many structure was used. In the second experiment, auditory stimuli were replaced by visual stimuli, for the samples used, for new students. A third experiment was implemented with an extra phase of training with compound stimuli for six new students. The structure of the experiments was: pretests (Xbcd–A; Xacd–B; Xabd–C; Xabc–D), training (A–B; A–C; A–D), and posttests (same as pretests). The difference between these conditions was the kind of stimuli used and a new phase of teaching used in condition 3: (Xbcd–A). The results indicate that training with simple stimuli on discriminations that include stimuli that are easy to discriminate from each other (words and sounds) is a sufficient condition for good posttest performance. However, when comparisons are made difficult (words only), participants show better performance on new tests if they have a learning history with compound stimuli.     

A preliminary investigation of fixed and repetitive models during object imitation training

Empirically based guidelines for imitation training for children with Autism Spectrum Disorder (ASD) are limited and there is no existing evidence about what types of imitative models foster faster acquisition of imitation in children with ASD. We compared rates of acquisition for two different methods for presenting the imitative model (i.e., repetitive, fixed) in simple (Experiment 1) and conditional (Experiment 2) discrimination arrangements. The results suggest that some children with ASD may acquire imitation more rapidly when repetitive models, rather than fixed models are used to present the target skill. In Experiment 3, we investigated the features of object imitation models that might influence acquisition. The results of Experiment 3 suggest that the dynamic nature of repetitive models might be responsible for the differential acquisition we observed in the earlier two Experiments. Additionally, the presence of an outcome (e.g., stacked blocks) during training does not enhance acquisition.     

Derived control by compound and single stimuli in a matching-to-sample task in children

A matching-to-sample procedure was used to investigate whether 9-year-old children would demonstrate the emergence of a derived compound-sample conditional discrimination following training in four interrelated single-sample conditional discriminations and vice versa, as adults did in previous studies. In Experiment 1, three out of three children demonstrated the emergence of a compound-sample conditional discrimination following training in four single-sample conditional discriminations. In Experiment 2, two out of three children acquired a compound-sample conditional discrimination and they demonstrated the emergence of four single-sample conditional discriminations; one of them did so only after being exposed to a remediation training and testing procedure. Training variables that facilitated discrimination emergence in both directions are discussed. In general, results showed that the sophisticated learning skills that are supposedly possessed by adults are not required to demonstrate the two types of derived control under study.     

Transfer of a conditional ordering response through conditional equivalence classes

Eight adult humans were taught conditional discriminations in a matching-to-sample format that led to the formation of two four-member equivalence classes. When subjects were taught to select one comparison stimulus from each class in a set order, they then ordered all other members of the equivalence classes without explicit training. When the ordering response itself was brought under conditional control, conditional sequencing also transferred to all other members of the two equivalence classes. When the conditional discriminations in the matching-to-sample task were brought under higher order conditional control, the eight stimulus members were arranged into four conditional equivalence classes. Both ordering and conditional ordering transferred to all members of the four conditional equivalence classes; for some subjects this occurred without a typical test for equivalence. One hundred twenty untrained sequences emerged from eight trained sequences for all subjects. Transfer of functions through equivalence classes may contribute to a behavior-analytic approach to semantics and generative grammar.     

Simple and conditional discriminations in rats: The effects of delays and scopolamine

In simple delayed discriminations (DD), the reinforcer depends on information available from the sample stimulus, whereas in delayed conditional discriminations (DCD), the reinforcer depends on information jointly available from the sample and the test stimuli. The present experiments compared performance in rats trained in DD and DCD (a) during acquisition over training sessions, and as a function of increasing (b) delay in the memory interval and (c) dosage with the anticholinergic scopolamine. In this work, clicks and tones served as sample stimuli, and bright and dim overhead lights served as test stimuli for lever pressing for food during the test stimulus. The DD task was acquired more rapidly and was more resistant to the effects of delay between the sample and test stimuli. These results replicate previous work with pigeons. In addition, the dose-performance function of scopolamine differed between DD and DCD. Performance declined as a linear function of drug dose in the DCD group. In contrast, performance declined abruptly as a stepwise function of drug dose in the DD group. These latter results suggest that the cholinergic system may be utilized differently during DD and DCD.     

Teaching multiply controlled intraverbals to children and adolescents with autism spectrum disorders

Reciprocal conversations, instructional activities, and other social interactions are replete with multiply controlled intraverbals, examples of which have been conceptualized in terms of conditional discriminations. Although the acquisition of conditional discriminations has been examined extensively in the behavior‐analytic literature, little research has evaluated procedures to establish multiply controlled intraverbals. Thus, the purpose of this investigation was to evaluate the effects of procedures based on conditional discrimination training on the acquisition of multiply controlled intraverbals with 7 participants who had been diagnosed with autism spectrum disorders. We evaluated the effects of prompt delay with error correction, a differential observing response (DOR), and a DOR plus blocked trials on the acquisition of intraverbals using a multiple baseline design. Accuracy of intraverbal performance increased for at least 1 set of stimuli for all participants under prompt delay with error correction conditions; however, 4 participants required additional teaching (i.e., DOR, modified DOR, modified prompt delay with error correction). Based on these findings, when prompt delay with error correction is not sufficient to establish multiply controlled intraverbals, prompted DORs may be an effective alternative.     

Assessment to identify learner-specific prompt and prompt-fading procedures for children with autism spectrum disorder

Few studies have evaluated the use of assessment to identify the most efficient instructional practices for individuals with autism spectrum disorder. This is problematic as these individuals often have difficulty acquiring skills, and the procedures that may be efficient with one individual may not be for others. The experimenters conducted instructional assessments to identify the most efficient prompt type (model, partial physical, full physical) and prompt-fading procedure (progressive delay, most-to-least, least-to-most) for teaching auditory–visual conditional discriminations for individuals with autism spectrum disorder. Each assessment was conducted at least twice, and a final generality test combined the most and the least efficient prompt type and prompt-fading procedure for teaching novel auditory–visual conditional discriminations. The results demonstrated learner-specific outcomes for the prompt type assessment, whereas the least-to-most prompt fading procedure was most efficient for all participants.     

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.     

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.     

Teaching autistic children to respond to simultaneous multiple cues

A number of studies have shown that autistic children tend to learn new discriminations by responding to only a restricted number of available cues and that this may be responsible for some of their abnormal behavior. Therefore, this investigation assessed the feasibility of teaching autistic children to respond to multiple cues. The results showed that four autistic children could learn a conditional discrimination requiring them to discriminate a multiple-cue complex from each of its two component cues. However, the autistic children did not learn this discrimination in the same manner as normal children. In the early trials, the autistics responded at a higher level to one of the two component cues. Only after many trials did the autistics respond equally on the basis of both component cues. The results of an initial attempt to teach a general set to respond to multiple cues showed that, when an autistic child was taught a series of successive conditional discriminations, the child eventually learned a set to approach new discriminations by responding equally on the basis of both component cues. The results are discussed in terms of understanding and treating autistic children's abnormal development.     

Performance of pigeons on delayed simple and conditional discriminations under equivalent training procedures

A pair of experiments investigated the short-term memory of pigeons under delayed simple and conditional discriminations. Trial sequences in both discriminations consisted of a color as the sample stimulus, a memory interval, a line orientation as the test stimulus, and a trial outcome, which was either food reinforcement or blackout. Pecking rates during the test stimulus defined discrimination performance. In the simple discrimination, the sample provided the necessary information regarding the subsequent trial outcome. In the conditional discrimination, the sample and test stimuli conjointly provided this information. In Experiment 1, the two procedures were compared with independent groups of pigeons. In Experiment 2, the comparison was made within subjects. The simple discrimination was acquired more quickly and was performed better with a memory requirement. Introduction of long delays disrupted performance even at shorter delays in both discriminations. Postulation of prospective as well as retrospective mediating processes facilitates the interpretation of these results.