Using multiple-exemplar training to teach a generalized repertoire of sharing to children with autism

The current study examined the utility of multiple-exemplar training to teach children with autism to share. Stimuli from 3 of 4 categories were trained using a treatment package of video modeling, prompting, and reinforcement. Offers to share increased for all 3 children following the introduction of treatment, with evidence of skill maintenance. In addition, within-stimulus-category generalization of sharing was evident for all participants, although only 1 participant demonstrated across-category generalization of sharing. Offers to share occurred in a novel setting, with familiar and novel stimuli, and in the presence of novel adults and peers for all participants during posttreatment probes.     

Evaluation of multiple schedules with naturally occurring and therapist‐arranged discriminative stimuli following functional communication training

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^Ds), but recently, researchers have evaluated similar multiple‐schedule training procedures with naturally occurring S^Ds (e.g., overt therapist behavior). The purposes of the current study were to compare the effects of arranged and naturally occurring S^Ds 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^Ds may promote rapid and generalized treatment gains.     

A transfer of functions through derived arbitrary and nonarbitrary stimulus relations

During Experiments 1 and 2, subjects were trained in a series of related conditional discriminations in a matching-to-sample format (A1-B1, A1-C1 and A2-B2, A2-C2). A low-rate performance was then explicitly trained in the presence of B1, and a high-rate performance was explicitly trained in the presence of B2. The two types of schedule performance transferred to the C stimuli for all subjects in both experiments, in the absence of explicit reinforcement through equivalence (i.e., C1 = low rate and C2 = high rate). In Experiment 2, it was also shown that these discriminative functions transferred from the C1-C2 stimuli to two novel stimuli that were physically similar to the C stimuli (SC1 and SC2, respectively). For both these experiments, subjects demonstrated the predicted equivalence responding during matching-to-sample equivalence tests. In Experiments 3 and 4, the conditional discrimination training from the first two experiments was modified in that two further conditional discrimination tasks were trained (C1-D1 and C2-D2). However, for these tasks the D stimuli served only as positive comparisons, and ND1 and ND2 stimuli served as negative comparisons (i.e., C1 × ND1 and C2 × ND2). Subsequent to training, the negatively related stimuli (ND1 and ND2) did not become discriminative for the schedule performances explicitly trained in the presence of B1 and B2, respectively. Instead, the ND1 stimulus became discriminative for the schedule performance trained in the presence of B2, and ND2 became discriminative for the schedule performance trained in the presence of B1. All subjects from Experiment 4 showed that the novel stimulus SND1, which was physically similar to ND1, became discriminative for the same response pattern as that controlled by ND1. Similarly, SND2, which was physically similar to ND2, became discriminative for the same response pattern as that controlled by ND2. Subjects from both Experiments 3 and 4 also produced equivalence responding on matching-to-sample equivalence tests that corresponded perfectly to the derived performances shown on the transfer of discriminative control tests.     

Control of echolalic speech in psychotic children

Immediate echolalia, a common language disorder in psychotic children, was studied in a series of replicated single-subject designs across six schizophrenic and five normal children. In Experiment 1, each child was presented with several questions and commands, some of which set the occasion for specific, appropriate responses and some of which did not. The former were referred to as discriminative stimuli and the latter, as neutral stimuli. The psychotic children tended to echo the neutral stimuli while responding appropriately to the discriminative stimuli; the normal children, in contrast, typically echoed neither type of stimulus. In Experiment 2, three psychotic children were taught appropriate responses to each of several neutral stimuli. Following this training, the children generally responded appropriately to these stimuli without echoing. A plausible interpretation of these results is that the neutral stimuli were initially incomprehensible or meaningless to the children (whereas the discriminative stimuli were comprehensible or meaningful) and that verbal incomprehensibility may be one important determinant of immediate echolalia. Finally, the results are noteworthy in that they isolate a sufficient treatment variable (i.e., the reinforcement of alternative, nonecholalic responses) for eliminating instances of this language anomaly.     

A practical variation of a multiple-schedule procedure: brief schedule-correlated stimuli

Multiple schedules using continuous discriminative stimuli have been used to minimize children's disruptive requesting for teacher attention (e.g., colored floral leis; Tiger & Hanley, 2004; Tiger, Hanley, & Heal, 2006). The present study evaluated the effectiveness of, and children's preferences for, two multiple-schedule arrangements in which brief experimenter vocalizations served as discriminative stimuli. Results showed that brief signals were highly effective discriminative stimuli for 3 of the 4 children, and that all children preferred one or both variations of the multiple schedule to a control arrangement. For 1 child, highly discriminated responding was achieved only when continuous signals were introduced.     

Autonomic concomitants of discriminative avoidance and punishment training in the monkey

TwoCebus albifrons monkeys were trained to press a back-lighted panel to postpone a brief electric shock to the tail using a Sidman avoidance schedule (SS = 40 sec, RS = 40 sec). After 25 training sessions, a discriminative schedule was introduced, with the Sidman avoidance continuing in the presence of one discriminative stimulus and punishment introduced in the presence of the other. The discriminative stimuli were colors on the panel. Discriminative training also involved 25 sessions, each with a random sequence of 6 avoidance and 6 punishment segments, with 30 sec intervals between the segments. Plantar skin conductance and heart rate were recorded along with the panel-pressing behavior. The two monkeys adjusted to the discriminative schedule quite differently from one another. One animal responded at a high level and avoided very well (during avoidance) but was punished frequently (during punishment). The other animal responded less frequently and received many shocks during avoidance but almost none during punishment. The animal that showed less ability to inhibit responding (and received about four times as many shocks overall) appeared to have discriminated better temporally in spacing its responses during avoidance training. The monkey whose panel-pressing behavior resulted in more shocks also tended to show a higher tonic level of autonomic arousal. However, within-animal differences in shock frequency (between avoidance and punishment) were not similarly related to autonomie arousal. The animal that received fewer shocks overall (but more during avoidance) showed greater arousal during punishment. The animal that received more shocks overall (but fewer during avoidance) showed no arousal differences between avoidance and punishment.     

Discrimination learning, the peak shift, and behavioral contrast

A discrimination between two successively alternating stimuli was trained under conditions that maintained equal frequencies of reinforcement in the presence of each of the discriminative stimuli (S1 and S2) but that also reduced the rate of responding to S2. These conditions included a multiple variable-interval differential-reinforcement-of-low-rate schedule and a multiple variable-interval variable-interval schedule in which responses to S2 were punished. Whenever the rate of responding to S2 was reduced, rate of responding to S1 (behavioral contrast) increased, and the peak of a subsequently obtained generalization gradient did not occur at the expected location (between S1 and S2) but was displaced away from S2, below S1. Discrimination training in which the frequencies of reinforcement earned in S1 and S2 were not equal (variable-interval 1-min variable-interval 5-min training) produced contrast and the peak shift only if the rate of responding to S2 had been reduced, as after non-differential reinforcement in which variable-interval 1-min schedules were correlated with S1 and with S2. It was concluded that a sufficient condition for the occurrence of behavioral contrast and the peak shift was reduction of the rate of responding to one of two alternating discriminative stimuli and that a peak shift will occur only if contrast had occurred during discrimination training.     

Superordinate categorization via learned stimulus equivalence: quantity of reinforcement, hedonic value, and the nature of the mediator

Three experiments examined superordinate categorization via stimulus equivalence training in pigeons. Experiment 1 established superordinate categories by association with a common number of food pellet reinforcers, plus it established generalization to novel photographic stimuli. Experiment 2 documented generalization of choice responding from stimuli signaling different numbers of food pellets to stimuli signaling different delays to food reinforcement. Experiment 3 indicated that different numbers of food pellets did not substitute as discriminative stimuli for the photographic stimuli with which the food pellets had been paired. The collective results suggest that the effective mediator of superordinate categories that are established via learned stimulus equivalence is not likely to be an accurate representation of the reinforcer, neither is it likely to be a distinctive response that is made to the discriminative stimulus. Motivational or emotional mediation is a more likely account.     

Teaching spontaneous responses to young children with autism

Using a multiple probe design across responses, we demonstrated the effectiveness of intensive intervention in establishing spontaneous verbal responses to 2 3-year-old children with autism with generalization to novel settings involving novel persons. Intervention involved discrete-trial instruction (i.e., repeated instructional opportunities presented in close proximity to high rates of reinforcement), specific prompts, and error correction. Spontaneous responses were defined as specific verbal utterances (e.g., the child says "bless you") following discriminative stimuli that did not involve explicit vocal directives (e.g., adult sneeze). The development of effective interventions to address the social-communicative needs of very young children with autism is discussed.     

Differences in the effect of Pavlovian contingencies upon behavioral momentum using auditory versus visual stimuli.

We examined the role of Pavlovian and operant relations in behavioral momentum by arranging response-contingent alternative reinforcement in one component of a three-component multiple concurrent schedule with rats. This permitted the simultaneous arranging of different response-reinforcer (operant) and stimulus-reinforcer (Pavlovian) contingencies during three baseline conditions. Auditory or visual stimuli were used as discriminative stimuli within the multiple concurrent schedules. Resistance to change of a target response was assessed during a single session of extinction following each baseline condition. The rate of the target response during baseline varied inversely with the rate of response-contingent reinforcement derived from a concurrent source, regardless of whether the discriminative stimuli were auditory or visual. Resistance to change of the target response, however, did depend on the discriminative-stimulus modality. Resistance to change in the presence of visual stimuli was a positive function of the Pavlovian contingencies, whereas resistance to change was unrelated to either the operant or Pavlovian contingencies when the discriminative stimuli were auditory. Stimulus salience may be a factor in determining the differences in resistance to change across sensory modalities.     

Stimulus effects on concurrent performance in transition

Six experimentally naive pigeons were exposed to concurrent variable-interval variable-interval schedules in a three-key procedure in which food reinforcement followed pecks on the side keys and pecks on the center key served as changeover responses. In Phase 1, 3 birds were exposed to 20 combinations of five variable-interval values, with each variable-interval value consistently associated with a different color on the side keys. Another 3 pigeons were exposed to the same 20 conditions, but with a more standard procedure that used a nondifferential discriminative stimulus on the two side keys throughout all conditions. In Phase 2, the differential and nondifferential stimulus conditions were reversed for each pigeon. Each condition lasted for one 5-hr session and one subsequent 1-hr session. In the last 14 conditions of each phase, the presence of differential discriminative stimuli decreased the time necessary for differential responding to develop and increased the sensitivity of behavior to reinforcement distribution in the 1st hr of training; during the last hours of training in each condition, however, the effects of the differential discriminative stimuli could not be distinguished from the effects of reinforcement distribution per se. These results show the importance of studying transitions in behavior as well as final performance. They may also be relevant to discrepancies in the results of previous experiments that have used nonhuman and human subjects.     

A method for studying stimulus class dynamics using budgerigars and vocal responding

We describe a methodology for examining stimulus class dynamics in budgerigars. Three budgerigars served as subjects. Four call types were trained as operant responses to four discriminative stimuli. The birds were over‐trained in this discrimination, and then run through two conditions. In Condition 1 the birds were trained to peck two of the four stimuli when these two stimuli appeared in two novel locations, while continuing to vocalize to all four stimuli when they occurred in the original training location. An analysis of vocal errors showed that the two stimuli assigned to the peck response were more likely to become confused with one another. In Condition 2 the birds experienced symbolic matching‐to‐sample training. Vocal discrimination trials were run concurrently with this training. The observed vocal‐response errors suggest that during a matching‐to‐sample task, sample stimuli became temporarily confused with one another. The results, although primarily intended to illustrate the utility of our method, support the hypothesis that stimuli assigned a common response become more similar, or equivalent, to one another.     

The Effect of a Multiple‐Schedule Arrangement on Mands of a Child with Autism

Clinical applications of multiple‐schedule arrangements have generally been used to produce discriminated manding. The present study evaluated the effects of a multiple‐schedule arrangement with rules on the rate of mands for one child diagnosed with autism. We sought to bring the participant's mands under discriminative control of adult behavior that closely matched naturally occurring discriminative stimuli in the participant's home environment. The results showed that discriminated manding emerged and responding continued in the presence of a novel therapist. Copyright © 2015 John Wiley & Sons, Ltd.     

Evidence for an association between the discriminative stimulus and the response-outcome association in instrumental learning

In 4 experiments, rats received 1 of several outcomes for engaging in various instrumental responses in the presence of discriminative stimuli. Discriminative stimuli shared some response-outcome relations but not others. When a response was subsequently extinguished in the presence of 1 discriminative stimulus, that produced relatively more decrement in responding in other stimuli that shared the same response-outcome relation. Other discriminative stimuli, in the presence of which that response had been reinforced by other outcomes and in which the original outcome had reinforced another response, were less affected. Moreover, postextinction devaluation of that outcome suggested that the particular response-outcome relation extinguished had undergone decrement. These results suggest that discriminative stimuli have relatively specific associations with the response-outcome relations that obtain in their presence.     

Stimulus control and compounding with ambient odor as a discriminative stimulus on a free-operant baseline

Previous experiments have demonstrated that the simultaneous presentation of independently established discriminative stimuli can control rates of operant responding substantially higher than the rates occasioned by the individual stimuli. This "additive summation" phenomenon has been shown with a variety of different reinforcers (e.g., food, water, shock avoidance, cocaine, and heroin). Discriminative stimuli previously used in such studies have been limited to the visual and auditory sensory modalities. The present experiment sought to (1) establish stimulus control on a free-operant baseline with an ambient olfactory discriminative stimulus, (2) compare olfactory control to that produced with an auditory discriminative stimulus, and (3) determine whether compounding independently established olfactory and auditory discriminative stimuli produces additive summation. Rats lever pressed for food on a variable-interval schedule in the presence of either a tone or an odor, with comparable control developed to each stimulus. In the absence of these stimuli responding was not reinforced. During stimulus compounding tests, the tone-plus-odor compound occasioned more than double the responses occasioned by either the tone or odor presented individually. Thus, the current study (1) established stimulus control with an ambient olfactory discriminative stimulus in a traditional free-operant setting and (2) extended the generality of stimulus-compounding effects by demonstrating additive summation when olfactory and auditory discriminative stimuli were presented simultaneously.     

Differential production of positive and negative discriminative stimuli by normal and retarded children

Using an observing procedure similar to Wyckoff's (1969), two normal and two mentally retarded children were studied. The children were initially trained to earn pennies by pressing a rectangular key according to a multiple variable-interval extinction schedule of reinforcement. After discrimination training, the children were allowed to produce the discriminative stimuli by depressing a second or observing key. The retarded children were different from the normal children in that they produced more of the positive discriminative stimulus (S+) than the negative discriminative stimulus (S?). In the case of the retarded children, S+ observing started high and remained high. In the case of the normal children, S+ observing was initially substantial and then rapidly diminished.     

Teaching self-protection to young children

Self-protective behaviors were taught to three preschool children in order to prevent the opportunity for abduction. An analogue measure of self-protection was developed in which confederate adults approached and verbally attempted to lure each child from the setting, before, during, and after training. A multiple baseline design across subjects was used. During baseline, all the children displayed susceptibility to the lures. Training procedures included modeling, behavior rehearsal, and social reinforcement. Within 1 week after training began, all children displayed appropriate responses to all of the lures both in the training setting and in the community.     

Motion as a natural category for pigeons: Generalization and a feature-positive effect

Three groups of pigeons were trained with a modified discriminative autoshaping procedure to discriminate video images of other pigeons on the basis of movement. Birds of all groups were shown the same video images of other pigeons, which were either moving or still. The group to whom food was presented only after moving images learned the discrimination very quickly. A second group, to whom food was given only after still images, and a pseudocategory group, to whom food was presented after arbitrarily chosen stimuli, showed no evidence of discrimination during acquisition training. Extinction conditions led to clear differences in peck rates to moving and still images in the second group but not in the pseudocategory group. The result is related to the feature-positive effect. Generalization tests showed that the discrimination performance was based on visual features of the stimuli but was invariant against changes of size, perspective, brightness, and color. Furthermore, discrimination was maintained when novel images of pigeons under different viewing angles and seven other types of motion categories were presented. It is argued that the discrimination is based not on a common motion feature but on motion concepts or high-order generalization across motion categories.     

SOCIAL SKILLS TRAINING WITH CHILDREN: PROCEED WITH CAUTION

Three learning disabled children, selected on the basis of peer sociometric ratings and teacher referral, received social skills training. A group training procedure consisting of coaching, modeling, behavior rehearsal, and feedback was used to teach children the target behaviors of eye contact and appropriate verbal responses. A multiple baseline analysis across target behaviors was used to demonstrate treatment effectiveness on role-play scenes trained during treatment sessions. Duration of speech was measured as an untrained, corollary measure. The following measures were also obtained during baseline, posttreatment, and 1-mo follow-up for the experimental subjects and three control subjects: (a) performance on role-play scenes not trained during treatment sessions; (b) behavioral observations in a free play setting, and (c) sociometric ratings. In addition, the trained and untrained role-play scenes were administered by novel experimenters following treatment. The results indicated that socially unskilled, learning disabled children can be taught to respond appropriately to role-play situations. However, improved performance did not generalize to the natural school setting and treatment did not effect ratings of peer acceptance. The implications of these findings for future social skills training with children are discussed.