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Two experiments were conducted to examine the effects of point-loss response cost on the responding under fixed-interval (FI) schedules in humans. Responses by undergraduates produced points exchangeable for money arranged according to an FI 90-s schedule (Experiment 1) or a multiple FI 30-s FI 60-s FI 90-s schedule (Experiment 2). Following this baseline, a contingency of response cost, under which responses lost points, was introduced then withdrawn. Response rates with the response cost were lower than those during the baseline. Following termination of the response cost contingency, the final response rates were again lower than those during the baseline (Experiments 1 and 2). Such low-rate responding was not found for participants who were exposed only to no-cost FI schedules (Experiment 2). These results demonstrate an irreversible effect of response cost. Generality and implications of the findings were discussed in the context of the research in punishment and human schedule performance. [ABSTRACT FROM AUTHOR]

The present experiment examined the effects of transmitted verbal descriptions on human responding under a schedule of reinforcement. An undergraduate (participant) was exposed to a multiple fixed-ratio (FR) 25 differential-reinforcement-of-low-rate (DRL) 5-s schedule. Then he was asked to describe how to obtain reinforcers. His description was presented to the next participant as instructions, prior to exposure to the same schedule. In this way, verbal descriptions generated by each participant were transmitted from one participant to the next for a total of 36 participants. Discrimination ratios, the ratios of the response rates during the FR component to the sum of the response rates during both components for these transmitted-instruction participants were higher than the ratios for no instruction participants who were exposed to the schedule with no instructions. The discrimination ratios positively correlated between successive participants with the transmitted instructions, whereas there was no correlation between the no instruction participants. These results were compared with previous results from experimental analyses of instructions and cultural transmission. [ABSTRACT FROM AUTHOR]

When reinforcement schedules demand that rats depress a lever for a minimum period of time, most lever presses will meet reinforcer requirements, but others will be much shorter. This results in a bimodal distribution of lever-press durations, with one peak near the reinforced duration value, and a smaller peak at less than 1 s. We conducted an experimental and descriptive analysis of short-duration presses in rats responding under a schedule that delivered edible reinforcers for 10 s of lever depression. All rats emitted biting and idiosyncratic behavior that may have both added and subtracted to the downward force necessary to maintain lever depression for extended periods. Movement of the response levers due to vigorous biting and sniffing, as well as premature hopper entries were both responsible for response durations that fell short of reinforcer requirements. Maintenance of long lever-press durations during fixed-time schedules in two out of three rats suggested that timing failure was unlikely a factor underlying bimodal distributions of response durations. [ABSTRACT FROM AUTHOR]

The present study investigated whether simple discrimination procedures produce emergent relations that are consistent with functional and equivalence classes. In Experiment 1, 4 normally capable adults were exposed to simple successive discrimination reversal training. Responses to the S (A1, B1, and C1) but not S (A2, B2, and C2) were reinforced. The participants were then exposed to repeated-reversal training, followed by tests of emergent equivalence relations. In Experiment 2, 4 additional adults were exposed to a simple successive discrimination training procedure using differential responses. Response 1 (R1) was reinforced only when emitted in the presence of A1, B1, or C1 (A1-R1, B1-R1, or C1-R1). Response 2 (R2) was reinforced only in the presence of A2, B2, or C2 (A2-R2, B2-R2, or C2-R2). A new response was then trained in the presence of 1 member of each class (A1-R3, A2-R4). A transfer-of-function test was then conducted to verify whether the new responses would be emitted in the presence of B1, B2, C1, and C2. In both experiments, emergent conditional relations were tested using a go/no-go procedure with compound stimuli. In Experiment 1, all of the participants showed functional classes, and 3 showed patterns that are consistent with the formation of equivalence classes. In Experiment 2, all 4 participants showed patterns that are consistent with functional and equivalence class formation. In these experiments, simple discrimination training generated a range of emergent stimulus relations that mirrored those that are indicative of equivalence class formation. [ABSTRACT FROM AUTHOR]

The present experiment demonstrated a procedure analyzing the behavior of controllers by measuring undergraduates' responses that produced consequences to other undergraduates. One member of each pair of 42 undergraduates, referred to as a learner, was asked to earn points exchangeable for money and told that touching a square shown on the screen of the display monitor may or may not change points. Unlike standard operant experiments, the point change was not determined by any computer program but by responses of another experimentally naïve undergraduate, referred to as an instructor. Response rates for 15 of 21 learners were higher than those for their yoked partners, who got and lost points independent of their responding. For 17 of 21 instructors, responses to an alternative (S key) that produced points to the learners were more than responses to another alternative (S key) that resulted in the learners' point loss. Each of 16 instructors pressed the S key more frequently after the learner responded than after the instructor pressed the S or S key. The mean interval between the learner's response and the instructor's S response was shorter than 1 s for each of 14 pairs of instructors and learners. Consistent with the behavioral principle of positive reinforcement, these results suggest that the instructors generally provided positive reinforcers depending on and immediately following the learners' responses. [ABSTRACT FROM AUTHOR]

The current study assessed whether the generalized matching law would provide an accurate description of behavior maintained by token reinforcement. A dependent-concurrent random interval 15 s schedule of token production maintained lever pressing in rats. Following delivery, each token could be immediately exchanged for sweetened condensed milk. In Experiment 1, the token ratio was either 1:3 or 1:9, depending upon condition, and the location of the rich schedule varied randomly across daily sessions. In Experiment 2, the token ratio varied randomly within each session (1:9, 1:6, 1:3, 1:1, 3:1, 6:1, and 9:1). Overall, the generalized matching law provided a good description of the data, revealing a high degree of undermatching. In Experiment 2, two of three rats tended to return to the just-productive lever following token delivery. The third subject showed this pattern only following left-token deliveries. Overall, the effects of token reinforcers on choice were similar to those observed with other reinforcers. [ABSTRACT FROM AUTHOR]

Background: Stimuli perfectly correlated with impending access to food have been shown to both attenuate response rates and to prevent response acquisition when they occur during delays to reinforcement. One explanation of these findings is that the stimulus better predicts food than the operant response itself, and therefore, 'blocks' learning of the response-reinforcer association. That such stimuli can abolish operant learning implies a breakdown in an organism's ability to detect causality between its own behavior and effects on the environment. Method: Two response acquisition experiments in which a stimulus preceded food delivery were conducted. In one experiment, an attempt was made to replicate the prevention of response acquisition using a non-resetting delay procedure that parallels those that result in overshadowing. In a second experiment, stimulus-food pretraining was given to provide a better parallel to typical respondent-conditioning blocking procedures. Results: Under neither circumstance was response acquisition prevented. Discussion: The generality and robustness of blocking the response-reinforcer association in operant response acquisition is questioned. [ABSTRACT FROM AUTHOR]

The present study assessed derived conditional relations using a within-subject sequence of training and testing with reinforcement. In Experiment 1, four undergraduates were trained on two independent arbitrary-matching tasks (A-B and C-D). Next, they were given reinforced symmetry trials for half of the baseline stimuli (B-A and D-C). To show that accuracy on symmetry trials was not a result of rapid learning due to reinforcement; novel relations were reinforced among the remaining baseline stimuli (B-C and D-A), as an experimental control. All participants acquired symmetrical relations faster than the novel, control relations. Experiment 2 assessed transitivity using a similar testing strategy. All but one participant acquired transitive relations faster than the novel, control relations. These results conform to those arising from traditional unreinforced tests and suggest the potential of the proposed strategy to study populations in which the emergence of conditional relations seems to be negatively affected by the suspension of reinforcement during tests. [ABSTRACT FROM AUTHOR]

Responding on variable-ratio (VR) schedules of wheel-running and sucrose reinforcement was assessed using a within-session procedure. Six female Long Evans rats were exposed to schedules ranging from VR 3 to VR 40 in ascending and descending order within a session with sucrose (0.1 ml of 15 % solution) and wheel-running reinforcement (30 s). Within a session, 10 reinforcers were obtained on each schedule, with a 120 s inter-component interval between schedules. Results showed that local response rates generated by sucrose were higher and that the pattern of local response rates across the schedules differed substantively between reinforcer types. With sucrose, local rates decreased linearly as the ratio requirement increased. With wheel running, local rates did not differ except to decline on the highest ratio. Post-reinforcement pauses were longer with wheel-running reinforcement and longer on the highest ratio when this ratio occurred at the end of a session. In contrast, wheel-running rates were lower on the smallest ratio schedule when this schedule occurred at the beginning of a session. The implications of the marked difference in local response rates across these schedules were discussed. [ABSTRACT FROM AUTHOR]

Can rats discriminate between short (i.e., 10 s) and long (i.e., 50 s) intervals of opportunity to run in running wheels? Eight female Long- Evans rats were exposed to 50 opportunities to run in a wheel. Following each interval, rats made a response to identify the interval. A correct response produced 0.1 ml of 15% sucrose solution, while an incorrect response caused the chamber lights to flash on and off for 5 s. Five of 8 rats met the criterion of 5 successive sessions with 80% correct responses for both durations. Furthermore, the criterion of 80% correct responses in a session was met more often with the 10-s than with the 50-s duration. Rats can discriminate between opportunities to run for different durations, but the results cast doubt on the assumption that rats are timing the intervals. [ABSTRACT FROM AUTHOR]

One member of each pair of 52 undergraduates, referred to as a learner, was trained BC conditional discriminations, with B stimuli as the samples and C stimuli as the correct comparisons. Responses of the learner were either reinforced or punished by another member of each pair, an instructor, who had previously mastered AC conditional discriminations, with A stimuli as the samples. The B sample stimuli were presented simultaneously with the A stimuli so that only the instructor could see the latter. Each learner mastered the BC conditional discriminations from his or her instructor, regardless of whether the learner saw the instructor in advance or not. Performance was less accurate when the B stimuli corresponded 83.3% with the A stimuli than when they corresponded 100%. These results extend previous findings on private events obtained from only two of eight pairs when the stimuli always corresponded. [ABSTRACT FROM AUTHOR]

The current study examined the variables that influence post-reinforcement pause (PRP) duration in rats when wheel running serves as the reinforcing consequence. The relationship between revolutions and PRP duration when revolutions were manipulated within a session and the effect of changing the response requirement from fixed to variable on PRP duration were evaluated. The operant was lever pressing and the reinforcer was the opportunity to run for a programmed number of revolutions. Results failed to show a positive correlation between revolutions run and PRP duration but did show that PRP duration was decreased by a variable response requirement. Analysis also revealed a within-session decrease in PRP duration. The implications of these findings for understanding the factors that influence PRP duration with wheel-running reinforcement are discussed. [ABSTRACT FROM AUTHOR]