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Temporal organization of behavior and delayed reinforcement |
Sunday, May 24, 2009 |
10:30 AM–11:50 AM |
North 226 AB |
Area: EAB; Domain: Experimental Analysis |
Chair: Rogelio Escobar (West Virginia University) |
Abstract: The effects of delayed reinforcement on a single operant response have been widely studied after Skinner’s first demonstration (1938). Nowadays, most behavior analysts agree that delayed reinforcement decreases the rate of the operant response. Increasingly, the interest in recent studies on delayed reinforcement has shifted from the unitary operant towards more complex forms of responding and more complex distributions of reinforcers. In the present symposium four studies concerning the effects of delayed reinforcement on the distribution of responses or choice over time will be presented: Bridi and Lattal determined the effects of signaled and unsignaled delays of reinforcement on short interresponse times. Elcoro and Lattal explored the effects of resetting and non-resetting delays on the temporal distribution of responding on a fixed-interval schedule. Escobar and Lattal made reinforcement contingent on a temporal pattern of responding to subsequently explore the effects of signaled delays on such shaped patterns. Andrade and Hackenberg determined the effects of the temporal distribution of reinforcers on choice between sequences of delayed reinforcers. By exploring the effects of delay on complex patterns of behavior the results of these four studies broaden the knowledge of behavior under delayed reinforcement. |
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Contingency and the Effect of Signaled Brief Delays of Reinforcement on Responding |
MORGAN S. BRIDI (West Virginia University), Kennon A. Lattal (West Virginia University) |
Abstract: Key-pecking was established under an immediate-reinforcement differential-reinforcement-of-high-rate (DRH) schedule in which only short interresponse times (<0.5 sec) were reinforced. In subsequent conditions a brief (0.5s) delay of reinforcement was added to the DRH schedule, either signaled (by blackout, tone, or keylight color change) or unsignaled. Delay signaled by blackout tended to decrease responding relative to the immediate reinforcement baseline. The tone and keylight color change signals were more variable, and increased responding slightly or did not change it. The unsignaled delay condition increased response rates. The characteristics of the functional response unit changed based on the delay used in each condition. These results run counter to those reported by some experimenters in the past, but are aligned with other data indicating that unsignaled delays change the functional response unit while signaled delays disrupt it. |
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Effects of delay of reinforcement on temporal control |
MIRARI ELCORO (Armstrong Atlantic State University), Kennon A. Lattal (West Virginia University) |
Abstract: Four pigeons were trained on fixed-interval (FI) 60-s schedules of reinforcement. Two types of delays of reinforcement were tested. One delay was programmed as a fixed-time (FT) schedule and the other as a differential-reinforcement-of-other-behavior (DRO) schedule. Three delay durations: 0.5, 1 and 10 s were examined. Effects of these delays on temporally-controlled responding were evaluated by measuring response rates and quarter-life values. Response rates tended to increase with 0.5-s delays and responses rates and QL values decreased with 10-s delays (with FT and DRO schedules). Delay gradients were calculated based on response rates and QL values. Effects of delay of reinforcement have been mostly examined using fixed-ratio and variable-interval schedules, but little is known about their effects on FI schedules. |
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The effects of delayed reinforcement on shaped behavioral patterns |
ROGELIO ESCOBAR (West Virginia University), Kennon A. Lattal (West Virginia University) |
Abstract: Different schedules of reinforcement produce widely known patterns of responding within the inter reinforcement interval. It can be argued that the patterns of responding are the result of the contiguity between some responses and reinforcement delivery. It is also possible to shape a particular temporal pattern of responding with a schedule in which the delivery of food is contingent upon the extent to which the temporal pattern of responding within a 4-s trial conforms to a criterion pattern. The occurrence of such patterns apparently challenges the fact that contiguity is an essential aspect of conditioning. However, in such case the response selected for reinforcement is the temporal pattern of responding and as such it may be sensitive to the effects of delayed reinforcement. The present experiment explored such possibility shaping two response patterns: a scalloped and a constant-response pattern in 3 pigeons. A signaled delay of reinforcement was added between the end of the 4-s trial and reinforcer delivery. The results support the fact that the lack of response-reinforcer contiguity notably decreases the rate of responding. |
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Choice, Delays, and Number of Reinforcers: An Analysis of Intertemporal Choice in Pigeons |
LEONARDO F. DE ANDRADE (University of Florida), Timothy D. Hackenberg (University of Florida) |
Abstract: When choosing between sequences of reinforcers distributed over time, pigeons’ preferences are strongly controlled by the delay to the first reinforcer in the sequence. The extent to which the delays to subsequent reinforcers in a sequence control choice is still largely unknown. By comparing choices between sequences of reinforcers delivered at the same overall rate but at different temporal patterning, the present experiment was aimed at assessing pigeons’ sensitivity to selectively delayed reinforcers in a sequence. Across phases of the experiment, the sequences consisted of either 2, 3, or 4 food reinforcers, but always included the same number and overall rate of food reinforcers across blocks of sessions (conditions) within a phase. Timed from the choice moment, the delay to an individual reinforcer in a sequence was selectively manipulated while maintaining constant the delay(s) to the other reinforcers in the sequence. In this way, sensitivity to a particular delay within a reinforcer sequence was assessed across phases, with repeated reversals conducted across conditions within a phase. Preferences were systematically related to the first, second, and sometimes the third reinforcer in sequence of reinforcers spanning 10-60 s. The results are broadly consistent with models of temporal discounting expanded to include the impact of sequences of delayed reinforcers acting in parallel from the time of the choice. |
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