Some experiments on the organization of a class of imitative behaviors

A retarded child was taught to imitate diverse demonstrations made by an experimenter, until new demonstrations were imitated correctly upon first presentation without direct training. These imitations could be maintained without reinforcement, when they were distributed among other reinforced imitations. Factors responsible for the continued performance of these unreinforced imitations were examined. When subjected to massed extinction trials, unreinforced imitations eventually disappeared; they reappeared when again interspersed among reinforced imitations. In addition, the stimulus function of "similarity of response between subject and experimenter" was examined. The subject was taught a set of non-imitative responses, through discriminative stimuli controlled by the experimenter, and a comparable imitative set. Unreinforced non-imitations, like reinforced imitations, were maintained only when interspersed among reinforced imitations. When all reinforcement was discontinued, all responses extinguished similarly, indicating that reinforcement was necessary to maintain the response-class organization, but not confirming an essential role for "similarity" as such.     

An analysis of generalized imitation

An experimenter presented English words to three intermediate-level children and reinforced accurate imitation of these words. The experimenter also presented novel Spanish words, but the imitation of these words was never experimentally reinforced. One subject quickly ceased performing non-reinforced imitative responses. The other two subjects were exposed to a series of conditions designed to facilitate discrimination. Upon observing the first subject for one session they immediately ceased imitating Spanish demonstrations. For all three subjects, when reinforcement was delivered for responses other than imitation, all imitative responses eventually ceased. When reinforcement was reintroduced for English imitations there was an immediate resumption of such responses to their previous 100% level. The occurrence of non-reinforced imitations in this and previous studies was discussed as being a function of one or combination of four variables: (1) similarity acquiring conditioned reinforcing properties, or (2) instructional, (3) coincidental, or (4) conditional stimulus generalization.     

Behavioral similarity as a reinforcer for preschool children

Three experiments evaluated whether behavioral similarity provided by an adult could serve as a reinforcer for the modelling behavior of four preschoolers. In each experiment, sessions consisted of two kinds of trials: (1) experimenter-modelled trials, when the child's imitation of modelled motor responses was reinforced with praise and tokens, and (2) child-modelled trials when experimenter imitation of child-modelled responses was contingent upon the child's modelling one of three alternative responses: operation of a ball, horn, or clicker. Experiment I showed that the children consistently modelled whichever responses the experimenter imitated. Experiment II determined whether that performance was due to differences in the amount of experimenter behavior following imitated versus nonimitated child models or to experimenter imitation. Neither reducing nor increasing the amount of experimenter behavior following the children's nonimitated models altered their modelling of imitated responses. Experiment III evaluated whether experimenter imitation of child models was a reinforcer because the child's imitative responses were reinforced on experimenter-modelled trials. In Experiment III, the children's nonimitation of experimenter-models was reinforced with praise and tokens on a schedule of differential reinforcement of other behavior, yet they continued to model experimenter-imitated responses on child-modelled trials. These results indicate behavioral similarity was reinforcing, though no conditioning history through which it acquired that function was demonstrated.     

The effect of incongruent instructions and consequences on imitation in retarded children

Three retarded boys served as subjects in a 13-phase experiment. In eight of these phases, the instructions administered by the experimenter before demonstrating a behavior and the consequences for imitative behavior were incongruent (the consequences were not those indicated by the instructions). Consequences rather than instructions controlled imitative behavior when (a) subjects were instructed not to imitate but received reinforcers if they imitated; (b) subjects were instructed to imitate but were differentially reinforced for other behavior; (c) subjects were instructed to imitate but were verbally reprimanded for imitation. Although subjects were highly imitative at the beginning of the study, when there was no reinforcement for imitation subjects gradually stopped imitating when instructed not to imitate. Instructions seemed to control imitative behavior when there was no reinforcement for imitation and subjects were instructed to imitate. These results indicated a need for further investigation of antecedent and consequent variables in imitation experiments and pointed out that certain techniques may be more efficient than others in eliminating well-established responses.     

THE DEVELOPMENT AND GENERALIZATION OF DELAYED IMITATION1

An individual's behavior can be identified as imitative if it temporally follows the behavior of another individual and if its topography is controlled by the demonstrated behavior [Baer, Peterson, and Sherman (Journal of the Experimental Analysis of Behavior, 1967, 10 , 405–416)]. This definition takes into account both temporal and topographical characteristics of the behavior in question. More recent research in the area of imitation has interpreted the temporal component of the above definition differentially by limiting imitation to those topographically similar responses occurring within 3, 5, or 10 sec after a model's demonstration. Yet, Gewirtz and Stingle (Psychological Review, 1968, 75 , 375–397) pointed out that much of the imitation seen in young children is not of this immediate nature, but instead occurs sometime after a model's response. They further suggest that this type of imitative behavior can be characterized as a response class and is susceptible to development and modification as a function of consequences delivered to subjects contingent on this type of delayed responding. Four retarded children, three initially imitative and one nonimitative, were individually trained to imitate a number of motor responses in an immediate and a delayed fashion. Immediate imitation was defined as a response similar to a model's demonstration occurring within 5 sec after the model's demonstration; delayed imitation was defined as a response similar to a model's demonstration occurring more than 5 sec, but not more than 25 sec, after the model's demonstration. A reversal (ABAB) design was employed to examine the experimental development of a generalized delayed imitative repertoire. Untrained probe responses were demonstrated to subjects systematically through the ongoing training. Generalized immediate and delayed imitation were observed in each subject; this generalization was restricted to the type of imitation currently undergoing training. This development of a generalized imitation repertoire was observed in each subject. That is, these subjects imitated some responses that had never been specifically trained. More importantly, a training package consisting of prompting, fading, and consequences for delayed imitation functioned to develop generalized delayed imitation. These data exemplify a special case of generalization that was a function of the most recent training history of immediate or delayed imitation. The reversal design demonstrated that imitations of nontrained models were either delayed or immediate, depending upon which form of imitation was currently receiving training. Therefore, for each form of imitation trained, delayed or immediate, a corresponding response class was demonstrated. These data relate to data reported by Garcia, Baer, and Firestone (Journal of Applied Behavior Analysis, 1971, 4 , 101–112). The association lies in the proposition that there are identifiable boundaries of generalized imitation and that these boundaries are functionally related to previous training histories.     

THE EFFECT OF EXPERIMENTER FACIAL ORIENTATION DURING IMITATION MAINTENANCE1

The training and maintenance of imitative responding has become an important therapeutic process with language-handicapped children, as indicated by Garcia and DeHaven (American Journal of Mental Deficiency, 1974, 79 , 169–178). Typically a training “package” is used, that might entail the use of operant shaping, fading, reinforcement, and punishment techniques designed to increase correct imitation and decrease incorrect responding. Only recently have studies begun to concentrate on the components of these training “packages”. Steinman (Journal of Applied Behavior Analysis, 1970, 3 , 159–167) highlighted the roles played by less conspicuous but functionally important components of these packages. The present study attempted to provide a systematic extension of this work within an applied context. Using subjects who were responding at high levels during an imitation-maintenance procedure, experimenter facial orientation (experimenter's eyes and head oriented towards the subject's face and head), was systematically manipulated for experimentally determined “types” of imitative behavior. Differential responding within these parameters provided an evaluation of facial orientation as a functional component within this training package. Three retarded children participated in the study. Two types of topographically different imitative responses were defined for experimental purposes (“standing” and “sitting”). Each subject progressed through four conditions of the study, which called for the reinforcement of all imitative responses. But during preselected conditions, experimenter facial orientation was removed from the therapeutic package for one of the two topographical types of imitation. Results indicated that imitation of the two topographical types of models was dependent on the presence of experimenter facial orientation within the experimental procedure.     

A variable influencing the performance of generalized imitative behaviors

This research attempted to demonstrate some of the conditions that would influence the performance of generalized imitative behaviors in young children. Two experiments were conducted. The results of Exp. I indicated that generalized imitative behaviors can be very durable; only one of three subjects was influenced by a variety of reinforcement-like procedures. Control over the behavior of all three subjects was obtained when a setting event involving the presence or absence of the experimenter was systematically varied. A second test of this variable was carried out in Exp. II. Results showed moderate to strong control over non-reinforced imitations in four preschool children.     

Child‐directed teaching and social learning at 18 months of age: evidence from Yucatec Mayan and US infants

In several previous studies, 18‐month‐old infants who were directly addressed demonstrated more robust imitative behaviors than infants who simply observed another's actions, leading theorists to suggest that child‐directed interactions carried unique informational value. However, these data came exclusively from cultural communities where direct teaching is commonplace, raising the possibility that the findings reflect regularities in infants' social experiences rather than responses to innate or a priori learning mechanisms. The current studies consider infants' imitative learning from child‐directed teaching and observed interaction in two cultural communities, a Yucatec Mayan village where infants have been described as experiencing relatively limited direct instruction (Study 1) and a US city where infants are regularly directly engaged (Study 2). Eighteen‐month‐old infants from each community participated in a within‐subjects study design where they were directly taught to use novel objects on one day and observed actors using different objects on another day. Mayan infants showed relative increases in imitative behaviors on their second visit to the lab as compared to their first visit, but there was no effect of condition. US infants showed no difference in imitative behavior in the child‐directed vs. observed conditions; however, infants who were directly addressed on their first visit showed significantly higher overall imitation rates than infants who observed on their first visit. Together, these findings call into question the idea that child‐directed teaching holds automatic or universal informational value.     

The development of generalized imitation within topographically determined boundaries

A multiple baseline technique was employed to examine the experimental development of an imitative repertoire within preselected topographical boundaries. Four severely retarded children, initially nonimitative, were individually trained to imitate a number of motor and vocal responses by shaping and fading procedures. Other untrained responses (probes) were demonstrated to the subjects systematically throughout the ongoing training. Training responses were divided into three topographical types: small motor, large motor, and short vocal responses. Probe responses were divided into four topographical types: small motor, large motor, short vocal, and long vocal responses. Following a multiple baseline format, sequential training of the first three types was begun at different temporal periods of the study; unreinforced imitative generalization was continually measured by the probes. Generalized imitation was observed in each subject (untrained responses were imitated even though unreinforced); but this generalization was restricted to the topographical type of imitation currently receiving training or having previously received training.     

The role of instructions in the transfer of ordinal functions through equivalence classes

In two experiments, adult subjects completed match-to-sample training and testing to establish four equivalence classes of four figures each. Then the subjects were taught one three-position sequence consisting of one stimulus from Class 1, one from Class 2, and one from Class 3. Inclusion of Class 4 stimuli in sequences was never reinforced, but two different stimuli from Class 4 appeared as distractors on each sequence trial. Tests assessed whether subjects would produce novel three-position sequences composed of members of Classes 1 through 3 that had not been used in sequence training. Three subjects in Experiment 1 received instructions about the match-to-sample and sequencing tasks, in addition to training contingencies. All 3 demonstrated equivalence class formation after match-to-sample training. After they were taught one sequence with one member of Classes 1 through 3, none of these subjects produced untrained sequences with other equivalence class members reliably. One additional sequence was trained directly; thereafter 1 subject showed some evidence of transfer of the trained ordinal functions across the remaining members of the equivalence classes, but the other 2 did not. Following a review of equivalence class training and testing and a review of the original sequence training, all 3 subjects produced most of the predicted, untrained sequences on tests. Experiment 2 replicated Experiment 1 with 2 adults but omitted all instructions except the minimal ones necessary to initiate responding. Unlike the subjects in Experiment 1, both of these subjects demonstrated virtually complete transfer of ordinal functions through the equivalence classes after direct training on just one sequence composed of one member of Classes 1 through 3.     

Acquisition and maintenance of matching without a required observing response

Two experiments demonstrated that matching-to-sample performance was improved when an explicit observing response was required to the sample stimulus. The first experiment demonstrated that fewer training sessions were required to establish matching with than matching without such a response. The second experiment demonstrated the dependence of established matching accuracy upon this observing response and the development in two of three subjects of a new overt observing response even when none was required by the experimenter.     

Human Intelligence After Removal of Cerebral Tissue from the Right Frontal LOBE

Present research explored the effect of conditioning history on the performance of imitative behaviors when a choice was given between a reinforced and a nonreinforced behavior or between two reinforced behaviors. The conditioning history consisted of exposure to a repeatedly demonstrated reinforced behavior (S^Dc). During subsequent choice presentations the S^Dc behavior was paired with a reinforced (S^Da) or nonreinforced (S-delta) alternative behavior. A multiple baseline design was utilized to control for the effect of the length of conditioning history. Six institutionalized retarded children served as subjects. The results indicated that the two subjects with no conditioning history imitated the S-delta behaviors as often as the S^Da behaviors and consistently more often than the S^Dc behaviors. In contrast, three of the four subjects who had the conditioning history imitated the S^Dc behaviors more often than both other behaviors and eventually stopped imitating the S-delta behavior. The fourth subject with a conditioning history did not show this response pattern, but showed a preference for imitating the last of two modeled behaviors. No systematic differences in imitative performance were observed between the two pairs of subjects with a conditioning history as a function of the length of conditioning history. The results suggest that the conditioning history may be largely responsible for the differential imitative performance of reinforced and nonreinforced behaviors.     

THE TRAINING AND GENERALIZATION OF A CONVERSATIONAL SPEECH FORM IN NONVERBAL RETARDATES1

Differential reinforcement and imitation were used with two retarded children to train three sequential verbal responses associated with the display of a picture and questions related to that picture. Each response consisted of a three-word chain in sentence form; combined with verbal responses from the experimenter, this trained sequence formed a short conversational unit. Three experimenters measured the use of each sentence in settings different than the one in which training took place, and with pictures different than those used during training. Two types of generalization sessions were used: (1) General sessions, during which 10 pictures never used during training were displayed to the subject with reinforcement delivered on a noncontingent basis, and (2) Intermixed sessions, during which 10 pictures never used during training were displayed to the subject, but a picture having received training was also displayed, and correct responses to this picture were reinforced on a variable schedule. Both subjects learned the sentences being trained. However, little generalization was evident from this training when all experimenters conducted General probe sessions. Generalization occurred with one experimenter only after that experimenter conducted Intermixed probe sessions. Generalization to a third experimenter was then observed (i.e., after the first two experimenters had conducted Intermixed probe sessions) without the use of Intermixed probe sessions by this third experimenter.     

Stimulus characteristics that can enhance or decrease aggression: Associations with prior positive or negative reinforcements for aggression

To establish an analogue of the “weapons effect,” male university subjects were required to use a distinctive apparatus in delivering noxious sounds to a peer in an adjoining room, and then were either (a) positively reinforced, or (b) negatively reinforced, or (c) not given any reaction by the experimenter, for what they had done. Immediately after this, each person had to administer other noise blasts to someone else in a different manner, but with the previous noise machines (the fist “weapon”) being either present or not present. The initial “weapon's” presence augmented the effects of the prior reinforcement; the second victim was attacked most strongly after the men had been positively reinforced and the earlier “weapon” was nearby, whereas he received the fewest blasts if the subjects had been negatively reinforced and the earlier noise machine was present. Other evidence indicates (1) that the aggressive cue, the “weapon,” had not affected the subjects' aggressive intentions, (2) the results are not due simply to differences in moods or general arousal, and (3) the subjects were not aware of the hypothesis regarding the interaction of reinforcement and cue presence.     

Promoting imitative play through generalized observational learning in autisticlike children

Three autisticlike boys with deficits in imitative and appropriate play behaviors were taught to play with an unfamiliar toy by observing a peer model demonstrate appropriate play with the toy. Generalization was assessed across toys and models, and temporal maintenance was assessed at 1 and 3 weeks following generalization. Following training each child demonstrated increases in imitative play concomitant with decreases in the frequency of nonmanipulated selfstimulatory behavior. Results are discussed in terms of their implications for the amelioration of social isolation and self-stimulatory behavior.The authors wish to acknowledge the help and cooperation of the Henry Wiseman Kendall Center and the Highpoint Preschool Enrichment Program.     

Arousal and imitation of aggression

Forty boys, aged 5 and 6 years, viewed either an aggressive or nonaggressive film and were tested for imitation of the behavior displayed in the film. On the next day, before being tested again for imitation of the film, half the subjects in each film condition engaged in arousing play with the experimenter, and half in quiet play. According to the prediction, those aroused on the second day displayed more imitative behavior than those not aroused, regardless of which film they had seen. The results are discussed in terms of arousal as a performance variable in social learning.Thanks are due to Louis Morris, for advice and suggestions, and to Jeffrey Cohen, for assistance in data collection. This research was facilitated by funds from the Tulane University Council on Research.     

Peer facilitation of generalization in a preschool classroom

Two 5-year-old deviant preschoolers taught each other, as peer-tutors, to identify pictorial figures describing prepositional relationships. During training sessions monitored by the experimenter, the child in the peer-tutor role presented stimulus materials and provided consequences for the responses of the child in the tutee role. An assessment of generalization by each child to an academic classroom setting occurred each day. The data showed that the peer-tutor could facilitate generalization, when the tutee was probed in the peer-tutor's presence. However, it was found that the salience of the peer-tutor's presence was critical to this effect. In particular, when the peer presented the stimuli or offered occasional consequences for some correct responses, generalization was greatly enhanced.This research was supported in part by PHS Training Grant HD 00183, Research Grant MH 11739, and a Dissertation Fellowship from the University of Kansas. Appreciation is expressed to the classroom teachers, Scott Simmons, Janet Wedel, Sue Parker, and Tena McEachern, for their patience and cooperation in the implementation of these procedures, and to Merril Stokes, for her help and encouragement during this study.     

Memory for actions in autism spectrum disorder

This study explored how memory for actions in children with autism spectrum disorder (ASD) and typically developing children might benefit from self-performance and experimenter demonstration, and whether these groups possess metamemory knowledge of their performance levels in this task. Children with autism were less accurate on the action memory task when they carried out each action themselves during encoding, or when no actions were implemented during this phase, but this difference was abolished when the experimenter demonstrated each action during encoding. Despite clear difficulties in the self-performed condition relative to typical children, the group with ASD also showed a beneficial effect of performing the actions themselves during instruction. Finally, children with autism were as accurate as typical children in judging the accuracy of their own memory performance, indicating an absence of metamemory difficulties for this task.     

TWO-TO-ONE versus ONE-TO-ONE STUDENT-TEACHER RATIOS IN THE OPERANT VERBAL TRAINING OF RETARDED CHILDREN1

The operant training of two retarded children simultaneously on a picture-naming task was investigated as an alternative to the more commonly reported one-to-one student-teacher ratio. In Experiment I, two conditions were compared in which the children received primary reinforcement on a fixed-ratio schedule for responding correctly on prompt and probe trials in a standardized picture-naming procedure. During the “Group Condition”, the experimenter alternated from one child to the other after each primary reinforcement, after each incorrect response, after each response omission, and after each 10-sec period in which a child did not “attend” (by making a trial-initiating response) when it was his or her turn to be worked with. During the “Individual Condition”, the experimenter worked with only one child, and presented trials whenever the child made attending responses. Experiment I demonstrated that the Group Condition was more efficient than the Individual Condition in terms of total correct responses and total pictures learned per unit of training time. Incidental learning was also found in that the children learned some of each others' pictures as well as their own, thus indicating a further advantage of the larger student-teacher ratio. In Experiment II, an attempt was made to equate the two conditions, except for the presence of two children in the Group Condition, by ignoring the child in the Individual Condition for brief periods equal to those that occurred in the Group Condition when the experimenter presented training trials to the other child. The results demonstrated that the greater efficiency of the Group Condition was not due to the manner in which training time was allocated to the two members of a group. It also replicated the finding that the children learned some of each others' words in the Group Condition.     

The social control of generalized imitation

Instructions, discrimination procedures, and sources of reinforcement were manipulated in order to determine the bases for the maintained "non-reinforced" imitations observed in generalized imitation research. Six girls received imitation training from two experimenters. One experimenter modelled only reinforced responses; the other modelled only non-reinforced responses. The children imitated all responses when no reinforced alternative was available, even though results of choice procedures and special instructions clearly demonstrated that they discriminated reinforced from non-reinforced responses. Instructions not to perform non-reinforced imitations immediately eliminated these behaviors. It is suggested that social setting events may be largely responsible for generalized imitation.