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# Chapter 14 AES

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### Chapter 14 AES

1. 1. Chapter 14. Imitation Theory: STIMULUS MATCHING AND IMITATION We show an observer a sample color (red) and two comparison colors (red and green). We ask the observer to select the comparison color that matches the sample color, and we reinforce the response of selecting the matching color. Behavior analysts often use this procedure with both human beings and animals. They call it stimulus matching or matching to sample. 1 The cluster of grapes is a poor person’s effort to symbolize a raisin reinforcer Now let's replace the colors with pictures of people. For example, the sample picture shows a woman with her right hand raised. One comparison picture shows the woman with her right hand raised, and the other comparison picture shows the woman with left hand raised. Then we reinforce selecting the picture that matches the sample picture in terms of the position of the hands. Next, we make the situation more concrete by replacing the pictures of the women 1 January 3, 2014
2. 2. with real women -- we could designate one as the sample woman, and the other two as comparison women. The correct response would be selecting the comparison woman whose position or behavior matches that of the sample woman. We could call the sample woman the model, and the two comparison women the imitators. We could reinforce selecting the proper imitation behavior of the two comparison imitators. The behavior of these women, then, is the discriminative stimuli for the appropriate selection response of the observer. When stimuli resulting from the behavior of the selected imitator match the stimuli resulting from the behavior of the model, the subject has selected the correct imitator. This is matching of imitation. As far as we know, behavior analysts haven't used this sort of discrimination procedure without the involvement of the subject actually doing the imitating, but it might be interesting. Now comes the main reason for pursuing this line: We substitute the observer for the imitator -- the usual imitation situation. Then we would reinforce the subject's matching the stimuli arising from his or her behavior to the stimuli arising from the behavior of the model. The matching stimuli would act as discriminative stimuli for the correct matching response. For example, if the model raises her right arm, the imitator would first look at the model and then look at or feel his or her right arm as he or she raised it. When the visual or proprioceptive (position) stimuli arising from the imitator's raised arm matched the visual stimuli of the model, the imitative response would be complete. The point of this is to suggest that imitation is a subclass of a more general type of stimulus control -- stimulus matching (matching to sample). The retarded child, or even you and I, acquire our imitative repertoire in the same way as the pigeon in the Skinner box acquires its stimulusmatching repertoire. In both cases stimulus matches produce reinforcers and nonmatches don't. There's nothing mystical or special about the behavioral processes underlying imitation, though the imitative repertoire is crucial to our learning to be normal human beings.2 QUESTIONS 1. Stimulus matching - define it and give an example. 2. Describe a series of hypothetical experiments showing how imitation is just a special form of stimulus matching. 2 Incidentally, I'm not saying imitation is more difficult or easier than other types of stimulus matching; that's an open question. I’m just saying imitation is a special type of stimulus matching. 2 January 3, 2014
3. 3. sponse-reinforcer contingency was important, which in turn shows that the food and praise were functioning reinforcers. Theory: THE PRINCIPLE OF GENERALIZED IMITATION Let's now address the complex problem of demonstrating the relevance of reinforcement in the development of generalized imitative behavior. Marilla could imitate a few responses without direct reinforcement of that imitation. But she still might need some reinforcement of at least some imitative responses. Baer and his colleagues studied the relevance of reinforcement in generalized imitation. To show that food and praise were functioning as reinforcers, in their control (comparison) condition, they needed to have the potential reinforcers present during the training session (just like the experimental condition). But they also needed to insure that those reinforcers didn't immediately follow imitative responses. They could insure that the food and praise never immediately followed the response, by waiting until Marilla stopped making imitative responses for 30 seconds. Then they could present the food and praise. As long as Marilla kept making imitative responses, no food and praise would occur. But as soon as she went for 30 seconds without making an imitative response, the experimenters would deliver food and praise. That way food and praise never immediately followed the imitative response. If Marilla made no imitative responses and just sat there, she could get a food and praise every 30 seconds.3 One way to show this relevance is to withhold the reinforcer and see if the response rate decreases. But, as you know, this will not be enough. Here's the problem: They didn't just want to show that giving food and praise was important. (For example, if they just did that, a critic might have said the food and praise were not reinforcers; it's just that giving Marilla food and praise put her in a good mood and made her want to imitate.) Instead, the experimenters needed to show that giving the food and praise immediately after the imitative response is what was important. That way they would be showing that the re- 3 January 3, 2014
4. 4. The effect of contingent removal of the potentially reinforcing consequences was striking. Over a period of less than 20 sessions, the frequency of imitative responses decreased until practically no imitation occurred. The decrease in the rate of these imitative responses was the same for both the generalized imitative responses and the previously reinforced imitative responses. (Of course, this meant that the rate of the delivery of the reinforcers was fairly high -- once every 30 seconds. So the noncontingent reinforcers probably could not account for the imitation.) These results indicate that the generalized imitative responses maintained because the behavior analysts reinforced the other imitative responses. In a sense, the researchers maintained the generalized imitation indirectly through reinforcement. But those imitative responses that have developed and have been maintained previously without direct reinforcement can't survive extinction of the entire class of imitative responses; for the generalized imitative response to maintain, some other members of the class of imitative response must be reinforced once in a while. This research is important because it helped Marilla learn to speak, and it also helped two other developmentally disabled children with whom the researchers used similar procedures. So this study produced remedial techniques of considerable generality. But that's not all. Their use of the control procedure to show the importance of the reinforce- ment contingency also provides evidence for the principle of generalized imitation, in addition to the concept of generalized imitation. In summary, we have the concept of generalized imitation -- imitation without reinforcement of imitation of that specific response. But that leaves the question of why does the person do generalized imitation. That's where the principle of generalized imitation comes in. The person does generalized imitation, because other imitative responses have been reinforced. Principle: Generalized imitation - Generalized imitation occurs,  only if some other imitative responses are being reinforced. QUESTIONS 1. The principle of generalized imitation -- state it and describe an experiment that provides evidence for it. Describe: a. The original training procedure that established generalized imitation b. The control procedure that showed the relevance of reinforcement for generalized imitation. 2. Relate this to the Zimmerman pigeon research. 4 January 3, 2014
5. 5. Theory: THE STIMULUS CONTROL OF GENERALIZED IMITATION We've looked at the control reinforcement exerts over generalized imitation. What about the nature of the imitative stimuli themselves? In other words, to what extent do the nature of the novel stimuli control our tendency to imitate them? For instance, how can we get a child to imitate a particular response (stimulus the model's behavior provides), when we had never before reinforced the child's imitating that response? If we look at the nature of the imitation stimulus, we may gain some understanding of this process. For example, suppose we've trained the child to say tall and fat. And suppose we've trained the child to imitate our saying tall and fat. Then we wouldn't be surprised if the child imitated us the first time we said fall. On the other hand, suppose we introduce a completely new word such as ring. Then we wouldn't be surprised if the child failed to imitate this word. In general, we would expect to get more imitation of novel responses (matching the behavior to novel stimuli), when those novel responses (stimuli) were more similar to the responses (stimuli) we'd used in the past. the stimuli arising from the behavior of the imitator are similar to those arising from the behavior of the model. But there's another type of imitation. In this type of imitation, the stimuli the imitator receives from his or her behavior are dissimilar from those he or she receives from the model's behavior. For example, the visual stimuli resulting from the model scratching the back of his or her head differ from the visual, proprioceptive (muscle), and tactual stimuli resulting from the imitator's scratching his or her own head. We can again ask questions about the transfer of such imitative behavior, but we would expect it to be less general than when 1. Similar to the modelgenerated stimuli during training? 2. Completely dissimilar from the model-generated stimuli during training? With dissimilar stimuli, we might train a naive subject to scratch the back of his head at the same spots as the model did. During testing, we could use new spots; and we might expect the imitator would respond correctly as long as those new spots were similar to the ones we used during training. But suppose that, during testing, the stimulus consisted of the model using his or her tongue to push out his or her right or left cheek. Then we would have little reason to think the naive imitator would respond appropriately. There should be little or no stimulus generalization or response generalization (response induction) from imitation of head scratching to imitation of tongue pushing, because the stimuli resulting from those two responses are so different. QUESTIONS 1. What are the issues of stimulus control of imitation when the novel model-generated stimuli are 5 January 3, 2014
6. 6. CONCEPTUAL QUESTIONS 3. Is the tendency to imitate innate or learned? Please justify your answer. a. for human beings b. for other animals 1. What's the social and behavioral significance of the invasion of the advertisers from outer space? 2. Describe something similar to stimulus matching in your life. 1 The cluster of grapes is a poor person's effort to symbolize a raisin reinforcer. 2 Incidentally, I'm not saying imitation is more difficult or easier than other types of stimulus matching; that's an open question. I'm just saying imitation is a special type of stimulus matching. 3 This is a special type of punishment procedure, punishment by the prevention of the presentation of a reinforcer (Chapter 16). (Some behavior analysts would call this procedure differential reinforcement of other behavior [DRO]. But, in Chapter 16, we will suggest that this isn't the best label for such a procedure.) 6 January 3, 2014