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| International Paper Session - Observing and Conditioned Reinforcement |
| Saturday, May 24, 2008 |
| 3:30 PM–4:50 PM |
| Metra |
| Area: EAB |
| Chair: Bryan S. Lovelace (University of North Texas & Texas Department of Ag) |
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| Observing and Attending in a Delayed Matching-to-Sample Preparation in Pigeons. |
| Domain: Basic Research |
| BRYAN S. LOVELACE (University of North Texas), Manish Vaidya (University of North Texas) |
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| Abstract: Pigeons worked in a titrating delay match-to-sample procedure (TDMTS) in which correct comparison selections increased the delay between sample offset and comparison onset and incorrect comparison selections decreased that delay. These procedures hold accuracy constant while allowing the retention interval to change dynamically and provide a more sensitive measure of the effects of manipulations that influence short term remembering. Prior research in our lab has shown that the adjusted stable value of the retention interval is a curvilinear function of the observing response requirement. The current study examined the effect of the distribution and predictability of observing response requirements on adjusted retention interval values. The data show that unpredictable observing response requirements were more effective in attenuating the deleterious effects of delay on matching accuracy. The data have implications for our understanding of attending and encoding in performances that involve remembering over short temporal durations. |
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| Temporal Location of Food and Stimulus Removal in Observing Procedures with an Added Clock. |
| Domain: Basic Research |
| ROGELIO ESCOBAR (National Autonomous University of Mexico), Carlos A. Bruner (National Autonomous University of Mexico) |
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| Abstract: The function of stimuli associated with successive periods of an extinction component in observing procedures was determined in rats. A mixed schedule of reinforcement in which an extinction component averaging 60 s alternated with a 20 s reinforcement component was used. In one experiment response-independent food was delivered either at the beginning or at the end of the reinforcement component. Concurrently, each press on a second lever produced for 5 s an added-clock stimulus associated with successive 20 s subintervals of the extinction and the reinforcement components. Observing responses increased from the beginning to the end of the extinction component when food was delivered at the end of the reinforcement component and remained constant throughout the extinction component when food was delivered at the beginning of the component. In another experiment the clock stimuli were removed in successive conditions. Observing responses markedly decreased when the stimulus associated with the reinforcement component (S+) was removed and decreased to some extent when the stimuli at the end of the extinction component was removed. When only the S+ was presented observing responses decreased and remained constant throughout the extinction component. The results were interpreted in terms of higher-order conditioning. |
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| Few Reinforcements of the Food-Producing Response Establishes Observing Behavior. |
| Domain: Basic Research |
| TAOKUENESHI VILLEGAS ROMERO (Universidad Nacional Autonoma de Mexico), Carlos A. Bruner (Universidad Nacional Autonoma de Mexico) |
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| Abstract: In a previous study we showed that extensive preliminary training is not necessary to establish observing behavior in rats and that observing responses occur spontaneously once the food-producing response is acquired. The observing procedure consisted in a two-lever concurrent schedule. Left-lever responses produced pellets on a mixed Random Interval (RI) 8 s extinction schedule, each component lasting 32 and 64 s, respectively. Each right-lever press produced a 6 s signal different for each component of the mixed schedule. In that study, it was found that it did not matter whether the food-producing response was reinforced as few as 13 or as many as 1000 times. In the present study we asked if observing behavior would develop in three rats each exposed to the prior reinforcement of the food-producing response either 8 or 24 times on a RI 4s schedule. All six rats in the study developed observing responding within 10 sessions once the observing procedure was instated. These results not only verify that extensive preliminary training is not necessary to establish complex behavior sequences, such as that involved in observing behavior in rats, but also show that the acquisition of responding for conditioned reinforcement involves very little prior training. |
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| Contingent Stimulus Presentations Determine the Effect of Infrequently Delivered Food Reinforcers. |
| Domain: Basic Research |
| NATHALIE JEANNE BOUTROS (University of Auckland), Michael C. Davison (University of Auckland), Douglas Elliffe (University of Auckland) |
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| Abstract: Response-contingent keylight illuminations and response-contingent food-deliveries were presented to pigeon subjects on a 2-alternative concurrent schedule. The left:right food reinforcer ratio and the left:right response-contingent keylight ratio were varied as was the pairing relationship between the stimuli and food. Davison and Baum (2006) conducted a very similar experiment using a rapidly changing procedure; they found that whether the response-contingent stimuli had reinforcer-like effects or not was dependent on the food-stimulus correlation and not on the pairing, or contiguity, relationship with food. Our results did not replicate Davison and Baum’s: typical reinforcer effects were found after all paired stimulus presentations regardless of the food-stimulus correlation and no obvious reinforcer-like effects were found with unpaired stimuli. However, the effect of contingent food deliveries in these conditions appeared to be a function of the food-stimulus correlation. Additionally, there appeared to be an effect after stimuli from the lean-food alternative that was not present after stimuli from the rich-food alternative. This effect seemed to be dependent on the food-stimulus correlation. The implications of these findings for the concept of conditioned reinforcement and the stimulus control of choice behaviour will be discussed. |
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