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1.
T W Belke 《Journal of the experimental analysis of behavior》1997,67(3):337-351
The present study investigated the effect of reinforcer duration on running and on responding reinforced by the opportunity to run. Eleven male Wistar rats responded on levers for the opportunity to run in a running wheel. Opportunities to run were programmed to occur on a tandem fixed-ratio 1 variable-interval 30-s reinforcement schedule. Reinforcer duration varied across conditions from 30 to 120 s. As reinforcer duration increased, the rates of running and lever pressing declined, and latency to lever press increased. The increase in latency to respond was consistent with findings that unconditioned inhibitory aftereffects of reinforcement increase with reinforcer magnitude. The decrease in local lever-pressing rates, however, was inconsistent with the view that response strength increases with the duration of the reinforcer. Response rate varied inversely, not directly, with reinforcer duration. Furthermore, within-session data challenge satiation, fatigue, and response deprivation as determinants of the observed changes in running and responding. In sum, the results point to the need for further research with nonappetitive forms of reinforcement. 相似文献
2.
Belke TW 《Journal of the experimental analysis of behavior》2000,73(2):225-239
Previous investigations of wheel-running reinforcement that manipulated reinforcer duration across conditions showed a strong relation between wheel-running rate and average postreinforcement pause (PRP) duration. To determine if the basis of this relation across conditions was a local effect of fatigue or satiation, the correlation between revolutions run and the duration of the immediately following PRP was investigated under conditions in which reinforcer duration was either constant or variable within a session. Seven male Wistar rats pressed a lever on a fixed-interval 60-s reinforcement schedule with the opportunity to run for 60 s as the reinforcing consequence. In the constant-duration condition, the duration of the reinforcer was always 60 s. In the variable-duration condition, the duration of the reinforcer varied between 2 and 240 s with a mean of 60 s. Mean correlations between revolutions run and the next PRP duration for constant, variable, and constant conditions were -.07, .20, and -.07, respectively. Although the positive correlation in the variable-duration condition is consistent with an effect of momentary fatigue or satiation, little of the variance in PRP duration appears to be attributable to these factors. 相似文献
3.
Bar presses by one group of rats were conditioned under a differential-reinforcement-of-low-rate reinforcement schedule immediately prior to conditioning under a fixed-interval schedule. In a second group of rats, bar presses were conditioned first under a differential-reinforcement-of-low-rate schedule and then under a fixed-ratio schedule prior to conditioning under a fixed-interval schedule. Low response rates occurred under the fixed-interval schedule only when it was immediately preceded by low-rate conditioning. Otherwise, fixed-interval responding was similar to responding under the fixed-ratio schedule. This finding suggests that responses of laboratory animals are sensitive to immediate history, and, unlike human responses, are relatively insensitive to a history of low-rate conditioning when it is followed by high-rate conditioning. 相似文献
4.
Three experiments describe the effects of manipulating the frequency of response-reinforcer contiguity in a recycling conjunctive schedule. The schedule arranged that a reinforcer was delivered after 30 s provided at least one response had occurred; otherwise the next cycle started immediately. In Experiment 1, this schedule produced the typical pause–respond–pause pattern, with most responses at mid-interval; and, when a limited number of contiguities between responses and food delivery were added, the pattern became more like the monotonic scallop seen on fixed-interval schedules. In Experiment 2, the schedule was initially presented with an additional contingency that allowed contiguity on every trial. Fixed-interval-like behavior occurred and tended to persist as contiguities were gradually eliminated. In Experiment 3, the recycling conjunctive schedule alternated with a condition in which a large number of contiguities occurred. The pause–respond–pause pattern and fixed-interval-like performance occurred with few or many contiguities, respectively. The results of all three experiments illustrate how contiguity interacts with a small number of other variables to determine performance on interval schedules and illuminate previous findings with fixed-interval and fixed-time schedules. 相似文献
5.
Molecular analyses of the effects of d-amphetamine on fixed-interval schedule performances of rats.
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A series of doses (0.5 to 2.0 mg/kg) of d-amphetamine was administered to rats whose lever pressing was maintained by fixed-interval 30-s, 60-s, or 120-s schedules of reinforcement by sucrose delivery. Under both saline and d-amphetamine conditions, molecular features of responding were reliably described in terms of the distribution of postreinforcement pauses and local response rate following the onset of responding. Postreinforcement pause always varied from interval to interval but, on average, shortened under the drug. Local response rate (response rate exclusive of pause time) tended to decrease under the drug, and where acceleration occurred within runs of responses, it was reduced by the drug. All of these effects were dose-related. These findings suggest that fixed-interval behavior can be analyzed effectively at a molecular level, and that the effects of d-amphetamine are best described as disruption of temporal discrimination. 相似文献
6.
Rate-dependent drug effects have been observed for operant responding maintained by food, water, heat, light onset, electrical brain stimulation, shock-stimulus termination, and shock presentation. The present study sought to determine if the effects of cocaine on lever pressing maintained by the opportunity to run could also be described as rate dependent. Seven male Wistar rats were trained to respond on levers for the opportunity to run in a wheel. The schedule of reinforcement was fixed-interval 60 s, and the reinforcing consequence was the opportunity to run for 60 s. On this schedule, overall rates of responding were low, usually below six presses per minute, and pauses frequently exceeded the 60-s interval. Despite these differences, an overall scalloped pattern of lever pressing was evident for each rat. Doses of 1, 2, 4, 8, and 16 mg/kg cocaine were administered 10 min prior to a session. Only at the 16 mg/kg dose did the responding of the majority of rats change in a manner suggestive of a rate-dependent drug effect. Specifically, lower response rates at the beginning of the intervals increased and higher rates at the end of the intervals decreased, as indicated by the fact that slopes from the regression of drug rates on control rates decreased. These data provide tentative support for the generalization of rate-dependent effects to operant responding maintained by wheel running. Differences in the baseline performance maintained by wheel running compared to those for food and water point to the need for further experimentation before this effect can be firmly established. 相似文献
7.
Variable-ratio conditioning history produces high- and low-rate fixed-interval performance in rats 总被引:8,自引:8,他引:0
B A Wanchisen T A Tatham S E Mooney 《Journal of the experimental analysis of behavior》1989,52(2):167-179
Four rats were exposed to an A-B-A-B series of 30 sessions each of variable-ratio 20 (A) and fixed-interval 30-s (B) schedules. Four other rats received 120 sessions of fixed-interval 30 s. The rats with a history of variable-ratio responding subsequently showed primarily high or low response-rate patterns on the fixed-interval schedule without evidence of classical scalloping (i.e., increased rates of responding throughout the interreinforcement interval), except infrequently in 1 rat. The rats exposed to only the fixed-interval 30-s schedule displayed the expected sequence of scalloping giving way to lower rate break-run or simply low-rate responding over time. This experiment shows that when naive rats are exposed to even a simple history of reinforcement (in this case, a variable-ratio 20), their subsequent fixed-interval performance is very different from comparable performance in naive rats, and might be said to be more similar to the responding of adult humans. The argument is made that care should be taken in comparing the fixed-interval performance of humans and nonhumans because humans have a complex history of reinforcement, whereas laboratory nonhumans are typically naive. 相似文献
8.
C Urbain A Poling J Millam T Thompson 《Journal of the experimental analysis of behavior》1978,29(3):385-392
Sixteen rats were initially exposed for 50 sessions to either a fixed-ratio 40 or an interresponse-time-greater-than-11-second food reinforcement schedule, then shifted to a fixed-interval 15-second food reinforcement schedule. Animals with fixed-ratio 40 histories lever pressed at much higher rates under the fixed-interval schedule than did animals with inter-response-time-greater-than-11-second histories. This difference persisted across 93 sessions of fixed-interval exposure. The effects of d=amphetamine were assessed after 15 and 59 sessions of fixed-interval exposure. On both occasions, the low-rate responding of animals with interresponse-time-greater-than-11-second histories was typically increased by all doses of the drug, while the high-rate responding of animals with fixed-ratio 40 histories was typically decreased by all doses of the drug. These results suggest that control response rate under the fixed-interval schedule, which may be affected by a history of responding under another schedule, is the primary determinant of the relative effects of d-amphetamine. 相似文献
9.
A Leinenweber S M Nietzel A Baron 《Journal of the experimental analysis of behavior》1996,66(3):311-326
Progressive-interval performances are described using measures that have proven to be successful in the analysis of fixed-interval responding. Five rats were trained with schedules in which the durations of consecutive intervals increased arithmetically as each interval was completed (either 6-s or 12-s steps for different subjects). The response patterns that emerged with extended training (90 sessions) indicated that performances had come under temporal control. Postreinforcement pausing increased as a function of the interval duration, the pauses were proportional to the prevailing duration, and the likelihood of the first response within an interval increased as the interval elapsed. To assess the resistance of these patterns to disruption, subjects were trained with a schedule that generated high response rates and short pauses (variable ratio). When the progressive-interval schedule was reinstated, pausing was attenuated and rates were elevated, but performances reverted to earlier patterns with continued exposure. The results indicated that temporal control by progressive-interval schedules, although slow to develop, is similar in many respects to that for fixed-interval schedules. 相似文献
10.
Rats in a laboratory foraging simulation searched for sequential opportunities to feed in two patches that differed in the rate at which food pellets were delivered (controlled by fixed-interval schedules) and in the size of the pellets. The profitability of feeding in each patch was calculated in terms of time (grams per minute) and in terms of effort (grams per bar press). These values were the result of the imposed fixed interval, the size of the pellets, and the rate at which the rats pressed the bar in each condition. The rats ate more food and larger meals, but not more frequent meals, at the patch offering the higher rate of food consumption, calculated as grams per minute. The relative intake at any patch was a function of the relative rate of intake during meals at that patch compared to the other patch. Rats respond to explicit manipulations of feeding time in the same manner as they respond to manipulations of feeding effort. 相似文献
11.
Macdonall J 《Journal of the experimental analysis of behavior》1998,69(3):275-293
The contingencies in each alternative of concurrent procedures consist of reinforcement for staying and reinforcement for switching. For the stay contingency, behavior directed at one alternative earns and obtains reinforcers. For the switch contingency, behavior directed at one alternative earns reinforcers but behavior directed at the other alternative obtains them. In Experiment 1, responses on the main lever, in S1, incremented stay and switch schedules and obtained a stay reinforcer when it became available. Responses on the switch lever changed S1 to S2 and obtained switch reinforcers when available. In S2, neither responses on the main lever nor on the switch lever were reinforced, but a switch response changed S2 to S1. Run lengths and visit durations were a function of the ratio of the scheduled probabilities of reinforcement (staying/switching). From run lengths and visit durations, traditional concurrent performance was synthesized, and that synthesized performance was consistent with the generalized matching law. Experiment 2 replicated and extended this analysis to concurrent variable-interval schedules. The synthesized results challenge any theory of matching that requires a comparison among the alternatives. 相似文献
12.
Mice from replicate lines, selectively bred based on high daily wheel-running rates, run more total revolutions and at higher average speeds than do mice from nonselected control lines. Based on this difference it was assumed that selected mice would find the opportunity to run in a wheel a more efficacious consequence. To assess this assumption within an operant paradigm, mice must be trained to make a response to produce the opportunity to run as a consequence. In the present study an autoshaping procedure was used to compare the acquisition of lever pressing reinforced by the opportunity to run for a brief opportunity (i.e., 90 s) between selected and control mice and then, using an operant procedure, the effect of the duration of the opportunity to run on lever pressing was assessed by varying reinforcer duration over values of 90 s, 30 min, and 90 s. The reinforcement schedule was a ratio schedule (FR 1 or VR 3). Results from the autoshaping phase showed that more control mice met a criterion of responses on 50% of trials. During the operant phase, when reinforcer duration was 90 s, almost all control, but few selected mice completed a session of 20 reinforcers; however, when reinforcer duration was increased to 30 min almost all selected and control mice completed a session of 20 reinforcers. Taken together, these results suggest that selective breeding based on wheel-running rates over 24 hr may have altered the motivational system in a way that reduces the reinforcing value of shorter running durations. The implications of this finding for these mice as a model for attention deficit hyperactivity disorder (ADHD) are discussed. It also is proposed that there may be an inherent trade-off in the motivational system for activities of short versus long duration. 相似文献
13.
Three rats, lever pressing for food delivered on a fixed-interval 128-s schedule, were presented with a 16-s opportunity to drink from a retractable water source. The temporal placement of the water probe within the reinforcement cycle was varied sequentially, in steps of 16 s. Although the lever-pressing pattern was modulated by the intercalated water probe, water consumption during the probe itself was a decreasing function of time from the following reinforcer. These results were interpreted as evidence against the notion that schedule-induced drinking is a "ubiquitous" phenomenon and are congruent with results from other "intruded stimulus" experiments. 相似文献
14.
Deprivation and satiation: The interrelations between food and wheel running 总被引:1,自引:1,他引:1
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Two experiments were designed to assess whether depriving rats of food would increase the reinforcement effectiveness of wheel running (Experiment 1) and whether satiation for wheel running would decrease the reinforcement effectiveness of food (Experiment 2). In Experiment 1, a progressive-ratio schedule was used to measure the reinforcement effectiveness of wheel running when rats were deprived or not deprived of food. Completion of a fixed number of lever presses released a brake on a running wheel for 60 s, and the response requirement was systematically increased until the rat stopped pressing or until 8 hr had elapsed. The ratio value reached (and the total number of lever presses) was an inverted-U function of food deprivation (percentage body weight). In Experiment 2, when wheel running preceded test sessions, fewer food-reinforced lever presses were maintained by the progressive-ratio schedule, and responding occurred at a lower rate on a variable-interval schedule. An interpretation of these results is that deprivation or satiation with respect to one event (such as food) alters the reinforcement effectiveness of a different event (such as access to wheel running). 相似文献
15.
Diversity and substitutability of adjunctive activities under fixed-interval schedules of food reinforcement
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Roper TJ 《Journal of the experimental analysis of behavior》1978,30(1):83-96
Six rats received food contingent on pressing a lever on fixed-ratio 1, fixed-interval 30-second, and fixed-interval 60-second schedules, with concurrent access to a drinking spout, a running wheel, and a block of wood. Drinking, running, and chewing were monitored automatically, and these and other activities were observed directly during selected sessions. Because all sessions ended after delivery of 60 pellets, total time available for activities other than eating increased over the three schedules. Time spent contacting the lever and visiting the food tray increased in proportion to total available time, whereas the time spent in other activities changed in a complex manner such that drinking was the dominant adjunctive behavior in the 30-second condition, and running or chewing the dominant adjunctive behavior in five of six rats in the 60-second condition. General activity and grooming also occupied significant amounts of time. In a subsequent part of the experiment, running and chewing were prevented, and the majority of other activities, especially drinking and grooming, increased. The results show that (a) FI schedules of food reinforcement are accompanied by a wide variety of adjunctive activities; (b) the preferred activity differs according to the schedule duration; and (c) the extent to which activities substitute for one another is limited by the tendency for different activities to occupy different parts of the interreinforcement interval. 相似文献
16.
We investigated the possibility that human-like fixed-interval performances would appear in rats given a variable-ratio history (Wanchisen, Tatham, & Mooney, 1989). Nine rats were trained under single or compound variable-ratio schedules and then under a fixed-interval 30-s schedule. The histories produced high fixed-interval rates that declined slowly over 90 sessions; differences as a function of the particular history were absent. Nine control animals given only fixed-interval training responded at lower levels initially, but rates increased with training. Despite differences in absolute rates, rates within the intervals and postreinforcement pauses indicated equivalent development of the accelerated response patterns suggestive of sensitivity to fixed-interval contingencies. The finding that the histories elevated rates without retarding development of differentiated patterns suggests that the effective response unit was a burst of several lever presses and that the fixed-interval contingencies acted on these units in the same way as for single responses. Regardless of history, the rats did not manifest the persistent, undifferentiated responding reported for humans under comparable schedules. We concluded that the shortcomings of animal models of human fixed-interval performances cannot be easily remedied by including a variable-ratio conditioning history within the model. 相似文献
17.
Disruption of ongoing appetitive behavior before and after daily avoidance sessions was examined. After baselines of appetitive responding were established under a fixed-interval 180-s schedule of food presentation, 4 rats were exposed to 40-min sessions of the appetitive schedule just prior to 100-min sessions of electric shock postponement, while another 4 rats received the 40-min appetitive sessions just following daily sessions of shock postponement. In all 8 subjects, fixed-interval response rates decreased relative to baseline levels, the effect being somewhat more pronounced when the avoidance sessions immediately followed. The disruption of fixed-interval responding was only partially reversed when avoidance sessions were discontinued. During the initial exposure to the avoidance sessions, patterns of responding under the fixed-interval schedule were differentially sensitive to disruption, with high baseline response rates generally more disturbed than low rates. These disruptions were not systematically related to changes in reinforcement frequency, which remained fairly high and invariant across all conditions of the experiment; they were also not systematically related to the response rates or to the shock rates of the adjacent avoidance sessions. The results, while qualitatively resembling patterns of conditioned suppression as typically studied, occurred on a greatly expanded time scale. As disruption of behavior extending over time, the present data suggest that some forms of conditioned suppression are perhaps best viewed within a larger temporal context. 相似文献
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19.
Jonathan Buriticá Cristiano V. dos Santos 《Journal of the experimental analysis of behavior》2017,108(2):151-170
The concept of reinforcement value summarizes the effect of different variables, such as reinforcement delay, reinforcement magnitude, and deprivation level, on behavior. In the present set of experiments, we evaluated the effect of reinforcement devaluation on performance under FI schedules. The literature on timing and reinforcement value suggests that devaluation generates longer expected times to reinforcement than the same intervals trained under control conditions. We devalued reinforcement with delay in Experiments 1A, 1B, and 2, and diminished deprivation in Experiments 3A and 3B. Devaluation reduced response rates, increased the number of one‐response intervals, and lengthened postreinforcement pauses, but had inconsistent effects on other timing measures such as quarter life and breakpoint. The results of delayed reinforcement and diminished deprivation manipulations are well summarized as reinforcement devaluation effects. These results suggest that devaluation may reduce stimulus control. In addition, we argue that the process by which delayed reinforcement affects behavior might also explain some effects observed in other devaluation procedures through the concept of reinforcement value. 相似文献
20.
Food-deprived golden hamsters in a large enclosure received food every 30 sec contingent on lever pressing, or free while their behavior was continuously recorded in terms of an exhaustive classification of motor patterns. As with other species in other situations, behavior became organized into two main classes. One (terminal behaviors) increased in probability throughout interfood intervals; the other (interim behaviors) peaked earlier in interfood intervals. Which class an activity belonged to was independent of whether food was contingent on lever pressing. When food was omitted on some of the intervals (thwarting), the terminal activities began sooner in the next interval, and different interim activities changed in different ways. The interim activities did not appear to be schedule-induced in the usual sense. Rather, the hamsters left the area of the feeder when food was not due and engaged in activities they would normally perform in the experimental environment. 相似文献