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Reinforcement Effects |
Tuesday, May 31, 2005 |
9:00 AM–10:20 AM |
Boulevard B (2nd floor) |
Area: EAB |
Chair: Robert G. Vreeland (Behavior Analysis & Intervention Services) |
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Magnitude of Reinforcement and Variable Reinforcing Environments |
Domain: Basic Research |
CARLOS F. APARICIO (University of Guadalajara, Mexico), William M. Baum (University of California, Davis) |
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Abstract: The study of choice in variable reinforcing environments has shown regularity in the local effects of individual reinforcers on response and time allocation. In this study we manipulated reinforcer magnitude to assess its effects on preference. Within the same session, seven unsignaled reinforcer ratios were arranged for presses on two levers. Each component ratio provided a maximum of 10 reinforcers and terminated with a 1-minute blackout. In different conditions, we manipulated reinforcer magnitude independently of the reinforcer ratio. First, the reinforcer on the left lever was four food pellets and the reinforcer on the right lever was one pellet. In the second condition, these magnitudes were reversed. In the third condition, the left lever provided three pellets and the right lever two pellets. At an extended lever of analysis, preference was described well by the generalized matching law. Local analyses showed that the most recently obtained reinforcers had substantially larger effect on preference than less recently obtained reinforcers. That larger reinforcers produced larger and longer preferences is consistent with the idea that the variables controlling choice have both short- and long-term effects. |
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Haloperidol, Naltrexone, Travel Requirements, and Type Reinforcer |
Domain: Basic Research |
FRANCISCO JUSTINIANO VELASCO (University of Guadalajara, CEIC), Carlos F. Aparicio (University of Guadalajara, CEIC) |
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Abstract: Whereas haloperidol acts upon the motor system impeding the initiation of movements that are necessary for the emission of operant behaviors, the interest for food reinforcers goes away under the effects of naltrexone. The present study explored these ideas with rats responding for food, or saccharine pellets in a choice situation with eight levers and different travel requirements. Experiment 1 provided food pellets in four levers according to concurrent variable interval (VI) schedules of 300, 600, 1400 and 700 seconds; with the other four levers providing saccharine pellets according to the same concurrent schedules. In Experiment 2 all levers provided a mixture of food and saccharine pellets according to the same concurrent VI schedules. To visit four out of the eight levers, rats were required to travel a distance of 75 cm; the travel distance to the other four levers was 110 cm. Results of Experiment 1 showed that rats developed a strong preference for the levers providing saccharine pellets. In Experiment 2 preference favoured the levers requiring the shortest travel distance. Total response output in the levers was not affected by naltrexone, but it was reduced by haloperidol. Preference was not affected by either naltrexone, or haloperidol. |
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Spatial and Temporal Characteristics of Reinforcement and Behavior |
Domain: Basic Research |
ROBERT G. VREELAND (Behavior Analysis & Intervention Services) |
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Abstract: Behavior takes place in both time and space. In the “molar view” as described by Baum (2001, 2002), time is allocated to an activity according to the relative reinforcement rate associated with that activity as opposed to other available activities. However, temporal characteristics of reinforcement may also control topographical aspects of behavior. Alternatively, reinforcing topographical characteristics of behavior may have significant effects on the recorded rate of that behavior. The author presents research in which pigeons pecked a long response key for food under multiple schedules of reinforcement. When the rate of reinforcement was varied in one component, a typical “contrast” effect was observed for response rate in both the changed and unchanged components. Variability of response location also changed in both components as a function of reinforcement rate. In a second study, only responses to a certain location on the key (the reinforcement band) were reinforced in one component. As the size of the reinforcement band decreased, observed increases in response rate were as large than those observed when the reinforcement rate was increased. The author considers these findings in light of molecular and molar views of reinforcement, and in terms of the multiscaled analysis suggested by Hineline (2001). |
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