共查询到20条相似文献，搜索用时 31 毫秒
1.
Terry W. Belke 《Learning & behavior》1992,20(4):401-406
Four pigeons were exposed to multiple schedules with concurrent variable interval (VI) components and then tested for preference transfer. Half of the pigeons were trained on a multiple concurrent VI 20-sec, VI 40-sec/cuncurrent VI 4G-sec5 VI 80-sec schedule. The remaining pigeons were trained on a multiple concurrent VI 80-sec, VI 40-sec/concurrent VI 40-sec, VI 20-sec schedule-After stability criteria for time and response proportions were simultaneously met, four preference transfer tests were conducted with the stimuli associated with the VI 40-sec schedules. During the transfer tests, each pigeon allocated a greater proportion of responses (M=0,79) and time (M=0.82) to the stimulus associated with the VI 40-sec schedule that was paired with the VI 80-sec schedule than lo the VI 40-sec schedule stimulus paired with the VI 20-sec schedule. Absolute reinforcement rates on the two VI 40 sec schedules were approximately equal and unlikely to account for the observed preference. Nor was the preference consistent with the differences in local reinforcement rates associated with the two stimuli. Instead, the results were interpreted in terms of the differential value that stimuli acquire as a function of previous pairings with alternative schedules of reinforcement. 相似文献
2.
In two experiments, food-deprived rat subjects leverpressed for food in three successive training phases. In the first phase of both experiments, rats were exposed to a multiple schedule, one component of which produced a high rate of response, and the other of which produced a lower rate of response (multiple random ratio [RR], random interval [RI] in Experiment 1, and multiple differential reinforcement of high rate, differential reinforcement of low rate in Experiment 2). Rats were then transferred to a multiple fixed interval (FI; 60-sec, 60-sec) schedule, until the effects of the first phase on response rate were no longer apparent and their response rates did not differ from those of rats responding on a multiple FI 60-sec, FI 60-sec schedule without previously experiencing a multiple RR, RI schedule. During the third stage oftraining, all rats were placed into extinction. During extinction, rates of responding were higher in the component previously associated with the high rate of responding in Phase 1, and they were lower in the component previously associated with low rates of responding in Phase 1. These results suggest that resurgence effects, like other history effects, are controlled by previous rates of responding. 相似文献
3.
Patricia B. Cronin 《Learning & behavior》1980,8(3):352-358
Delayed-reward learning in pigeons was examined using a simultaneous red-green visual discrimination task in which the conditions during the delay interval were varied between groups. The nondifferential group received training in which the stimulus present during the 1-min delay was the same following a peck on the correct and incorrect colors. The other three groups received 1-min delay training in which different stimuli occurred in the delay interval following correct and incorrect choices. The differential group received continuous, differential stimuli during the delay. The reinstatement group received the differential stimuli in the 10 sec immediately following the choice and during the last 10 sec of the delay. The reversedcue group was treated in the same way, except that the 10-sec delay stimulus immediately following an incorrect response was also presented for 10 sec prior to reward on correct choices, and the stimulus following a correct response also occurred 10 sec before nonreward on incorrect choices. Nondifferential birds failed to learn the discrimination, while differential and reinstatement birds learned it readily. The reversed-cue birds learned to choose the incorrect stimulus. Differential and reinstatement birds showed no decrement in performance when the delay was increased to 2 min. These findings suggest that similarity of prereward and postresponse delay stimuli controls choice responding in long-delay learning, a finding compatible with both memorial and conditioned reinforcement interpretations. 相似文献
4.
R. J. Auge 《Learning & behavior》1977,5(2):117-123
Pigeons received food for responding on a fixed-interval 32-sec schedule divided into three equal parts, each correlated with a distinctive, response-independent, visual stimulus. Response rate was very low during the first two thirds of the interval but high during the terminal third. When a response-dependent brief stimulus correlated with the terminal third was arranged for each response in the presence of the stimuli correlated with the first two thirds, response rate was enhanced, especially in the middle third. However, response rate was suppressed when each response in the presence of the stimulus correlated with the final third produced a brief stimulus correlated with the initial third. A similar suppressive effect occurred when each response produced a brief stimulus correlated with the middle third. Response suppression decreased over successive response-dependent brief-initial-stimulus manipulations. The results were interpreted in terms of reinforcement, punishment, and discriminative stimulus control by visual stimuli correlated with parts of a fixed-interval schedule. 相似文献
5.
In each of two experiments, rats were trained to press the lever in a Skinner box, food reinforcement being available on a variable-interval 60-sec schedule (VI 60). There followed an “exposure phase” for which the levers were removed from the boxes, and then a final test with the levers replaced to assess the effects of the intervening treatment on instrumental responding. Experiment 1 showed that simple exposure to the box reduced the vigor of instrumental performance in comparison with a condition in which food was made available during the exposure phase. Animals which received no exposure treatment also showed a relatively high rate of response. Experiment 2 demonstrated that an exposure treatment in which the occurrence of food is signaled by a light stimulus also leads to a decline in instrumental responding. These results are held to support the notion that associations between the context and the reinforcer serve to energize appetitive instrumental behavior. 相似文献
6.
Pigeons’ choice responding on 10-sec interpolated probes was studied after baseline training on multiple variable-interval variable-interval schedules of food reinforcement. Unreinforced choice following training with three different relative reinforcement rates (Experiment 1), with a 3-ply multiple schedule (Experiment 2), and with three different relative reinforcement durations (Experiment 3) was examined. Least squares lines were fit to choice relative response rate and schedule relative response rate as functions of training relative reinforcement rate; choice slope was significantly greater than schedule slope in all three experiments. This result is counter to the prediction of Herrnstein’s (1970) theory that these slopes should not differ. Luce’s (1959) theory also failed to account for the data. It was concluded that choice responding was controlled by both approach to the stimulus associated with the smaller mean interreinforcer interval or the longer duration, and avoidance of the other stimulus. 相似文献
7.
We present an algebraic model of resistance to extinction that is consistent with research on resistance to change. The model assumes that response strength is a power function of reinforcer rate and that extinction involves two additive, decremental processes: (1) the termination of the reinforcement contingency and (2) generalization decrement resulting from reinforcer omission. The model was supported by three experiments. In Experiment 1, 4 pigeons were trained on two-component multiple variable-interval (VI) 60-sec, VI 240-sec schedules. In two conditions, resistance to change was tested by terminating the response-reinforcer contingency and presenting response-independent reinforcers at the same rate as in training. In two further conditions, resistance to change was tested by prefeeding and by extinction. In Experiment 2, 6 pigeons were trained on two-component multiple VI 150-sec schedules with 8-sec or 2-sec reinforcers, and resistance to change was tested by terminating the response-reinforcer contingency in three conditions. In two of those conditions, brief delays were interposed between responses and response-independent reinforcers. In both Experiments 1 and 2, response rate was more resistant to change in the richer component, except for extinction in Experiment 1. In Experiment 3, 8 pigeons were trained on multiple VI 30-sec, VI 120-sec schedules. During extinction, half of the presentations of each component were accompanied by a novel stimulus to produce generalization decrement. The extinction data of Experiments 1 and 3 were well described by our model. The value of the exponent relating response strength and reinforcement was similar in all three experiments. 相似文献
8.
Additive summation is observed when more responses are emitted to the simultaneous presentation (tone-plus-light) of independently conditioned stimuli (tone and light) than to either stimulus presented alone. The current experiment sought to determine if this increased rate during tone-plus-light was a function of a new modal interresponse time (IRT) or a differential mixing of pauses with a modal IRT characteristic of the responding in tone and light alone. Three rats were trained on a three-component multiple schedule where tone and light were each associated with a variable-interval 30-sec schedule while a variable-interval 100-sec operated in the simultaneous absence of these stimuli, tone-off and light-out. Baseline response rates were 2–4 times as high in tone or light as in their absence. In testing, more responses were emitted to tone-plus-light than to tone or light by all animals, but the modal IRT was in the 0.2–0.4-sec IRT bin for all test conditions. Tone-plus-light controlled fewer long IRT values and more responses in the short modal category than tone or light alone. These results support the response mixing hypothesis of stimulus control; i.e., no “new” behavior was observed during the novel combination of stimulus elements, only a mixture of previously reinforced behavior patterns in different proportions. 相似文献
9.
Rats were trained on reinforcement schedules which generated high or low response rates. After extinguishing responding by eliminating food-reinforcement delivery, response-independent food presentations reinstated responding. Higher response rates occurred if the schedule preceding extinction controlled high response rates, suggesting that discriminative stimulus properties of the reinforcer were a function of antecedent training schedules. 相似文献
10.
Brent Alsop 《Learning & behavior》1987,15(2):110-114
Six pigeons were trained on a multiple-concurrent schedule. During both multiple-schedule components, two response keys were available. In Component 1, responses to the left key were reinforced on a variable-interval 45-sec schedule, whereas responses to the right key were not reinforced. In Component 2, these contingencies were reversed. Following each reinforcer, the component next presented was chosen randomly with equal probability. The two components were differentially signaled by presentation of various stimuli during Component 1. Over the course of the experiment, these stimuli were various intensities of light, a noise, and various fluctuating and static magnetic fields. While subjects showed good discrimination of the light and noise stimuli, no stimulus control using the magnetic fields was obtained. 相似文献
11.
Pigeons were studied on multiple variable-ratio yoked-variable-interval schedules in which components had equal rates of food reinforcement and appeared equally often on each of two keys. Interpolated between component changes on the final multiple schedule were 10-sec probes in which both schedule stimuli were present, one on each key. During multiple schedule training, variable-ratio response rates were greater than yoked-variable-interval rates; however, response rate differences in the components were not a function of the mean ratio value for the 40-to-320-ratio range studied. During the choice probes, subjects responded more to the stimulus associated with the interval schedule than to the one associated with the ratio schedule. It was concluded that pigeons prefer interval schedules over equal reinforcement rate ratio schedules, because the former generate fewer responses per reinforcement. 相似文献
12.
James Allison 《Learning & behavior》1980,8(2):185-192
The conservation model was generalized to the variable-interval schedule by incorporating the concept of unscheduled instrumental responses, those which occur in the time before the next setup is due. Thirsty rats responded in constant-duration sessions on two 7-sec schedules that required one leverpress for 25 and 50 licks at a water tube and on a 14-sec 25-lick schedule. In accordance with the model, total licks decreased linearly as total presses increased, and the schedules facilitated leverpressing and suppressed licking relative to paired baseline levels of responding. While the matching model also gave a satisfactory fit to instrumental responding under the schedules, its two constants, representing asymptotic rate of responding and extraneous reinforcement, had anomalous values which led the model to predict that response rate would decrease as the rate of reinforcement increased, directly opposing its prediction for the constant-consumption experiments of its previous tests. 相似文献
13.
Jay Moore 《Learning & behavior》1976,4(4):441-450
Pigeons responded on a two-key concurrent chains choice procedure with the same level of percentage reinforcement on each key. During the initial links, a choice response on either key occasionally produced a conditioned reinforcer—which on one key was associated with a 15-sec, and on the other key with a 30-sec, interreinforcement interval—or an extinction stimulus. In Part 1, the initial links were equal. With successive decreases in the probability of a reinforcer, choice shifted from preference for the 15-sec terminal link toward indifference. In Part 2, the initial links were unequal and were arranged so that the shorter initial link preceded the 30-sec terminal link. At a high probability of a reinforcer, the pigeons again preferred the 15-sec terminal link. However, at a low probability, the pigeons reversed and preferred the alternate key. It was concluded that the conditioned reinforcers tended to become functionally equivalent at a low probability of a reinforcer, despite the nominally different interreinforcement intervals, with the result that choice was then modulated by the relative size of the initial links. The data are inconsistent with the view that choice and the strength of conditioned reinforcers are isomorphic with the reduction in delay to reward correlated with terminal link stimuli. 相似文献
14.
Ralph W. Richards 《Learning & behavior》1978,6(3):286-289
Pigeons were trained on a multiple variable-interval 5-min variable-interval 5-min schedule and then shifted to either a multiple variable-interval 1-min variable-interval 5-min or a multiple variable-interval 30-sec variable-interval 5-min schedule. A generalization test was subsequently administered along the dimension containing the stimulus associated with the variable-interval 5-min component. The generalization gradients for subjects that received multiple variable-interval 1-min variable-interval 5-min training were not consistent in shape. However, an incremental gradient was obtained from each subject that received multiple variable-interval 30-sec variable-interval 5-min training. Thus, a sufficiently large reduction in merely the relative frequency of reinforcement during a stimulus resulted in that stimulus’ acquiring inhibitory control over responding. 相似文献
15.
Previous experiments on behavioral momentum have shown that relative resistance to extinction of operant behavior in the presence of a stimulus depends on the rate of reinforcement associated with that stimulus, even if some of those reinforcers occur independently of the behavior. We present three experiments examining whether the rate of reinforcement in the presence of a stimulus similarly modulates the relative relapse of operant behavior produced by reinstatement, resurgence, and renewal paradigms. During baseline conditions, pigeons responded for food reinforcement on variable-interval 120-sec schedules in alternating periods of exposure to two stimuli arranged by a multiple schedule. Additional response-independent food presentations were also delivered in the presence of one of the multiple-schedule stimuli. Consistent with previous research, baseline response rates were lower in the presence of the stimulus with the added response-independent reinforcement, and relative resistance to extinction was greater in the presence of that stimulus. In addition, following extinction, the relative relapse of responding produced by reinstatement, resurgence, and renewal paradigms was greater in the presence of the stimulus associated with the higher rate of reinforcement. We suggest that a model of extinction from behavioral momentum theory may be useful for understanding these results. 相似文献
16.
In two experiments, pigeons' responding on an extraneous task was explicitly reinforced during delayed matching-to-sample
trials. In Experiment 1, red or green sample stimuli were followed by retention intervals of 0.2, 1, 4, or 12 sec, during
which pecks to a white center key were reinforced with 2.5-sec access to wheat according to extinction, variable-interval
30-sec, and variable-interval 15-sec schedules in different conditions. A proportion of .2, .5, .7, or .9 of subsequent red
or green choice responses that matched the sample were reinforced with 3-sec access to wheat. The result was that increasing
center key reinforcement, or reducing reinforcer probability, lowered overall accuracy. Initial discriminability fell, but
with no change in the rate of forgetting. In Experiment 2, initial discriminability was affected by extraneous reinforcers
that were contingent on center key pecking, but not by noncontingent reinforcers. A plausible conclusion is that initial discriminability
decreases when reinforcers strengthen competing behaviors. 相似文献
17.
The relationship between the duration of stimuli and their conditioned reinforcing effect was investigated using a learning-tests procedure. In Experiment 1, stimuli were the same duration on training (stimulus → reward) and test (choice response → stimulus). Ten- and 30-sec stimuli provided effective differential conditioned reinforcement but 3-sec stimuli did not. In Experiment 2, different pigeons had each combination of the 3- and 30-sec stimuli on training and test trials. Evidence of conditioned reinforcement was obtained only for the birds with 30-sec stimuli on both training and test. The results were interpreted as indicating that stimuli become effective conditioned reinforcers on test trials only when their duration exceeds the duration of differential short-term memory cues resulting from a difference in the events that precede them on training and test trials. 相似文献
18.
Pigeons received variable-interval (VI) reinforcement for keypecking during randomized presentations of seven line-orientation stimuli forming a continuum ranging from horizontal (0 deg) to vertical (90 deg). Each line presentation lasted for 30 sec and was preceded and followed by 30-sec time-outs. After responding stabilized, only responding in the two extreme stimuli (0 and 90 deg) was reinforced. As discrimination training proceeded, strong behavioral contrast and dimensional contrast effects appeared. However, only marginal local effects (local contrast and local dimensional effects), exerted by one line-orientation component upon a second, appeared, indicating that behavioral and dimensional contrast may be independent of parallel local effects. An attempt was made to apply Blough’s (1975) quantitative model of operant generalization and discrimination to the present discrimination procedure. However, this model did not predict the generalization gradient shape that was experimentally obtained. This experiment also yielded two serendipitous findings: (1) Positive behavioral contrast appeared in an extinction-related stimulus (time-out) when other stimuli were switched from reinforcement to extinction (hitherto, positive behavioral contrast had been observed only in responding to a reinforcementrelated stimulus when other stimuli were switched from reinforcement to extinction), and (2) final responding was higher in the presence of an extinction stimulus that had always been an extinction stimulus than it was in the presence of other extinction stimuli that had previously been paired with VI reinforcement. 相似文献
19.
Thirty rats received 10 sessions of baseline training in which leverpressing was reinforced according to a variable-interval (VI) 60-sec schedule. Twenty-four of the subjects were then assigned to one of four groups that received five sessions of extinction, with groups being differentiated in a 2 by 2 factorial design on the basis of: (1) changes in stimuli accompanying transportation of subjects from home cages to the laboratory and placement in the apparatus, and/or (2) changes in contextual stimuli within the apparatus. During the sixth session of extinction, the transportational and contextual stimuli previously associated with baseline training were reinstated. The remaining six rats experienced changes in both transportational and contextual stimuli but were maintained on the VI 60-sec schedule of reinforcement. Changes in either transportational or contextual stimuli reduced resistance to extinction and spontaneous recovery, and substantial increments in responding occurred upon reinstatement of the transportational and contextual stimuli associated with baseline training. Evidence for summation of the two sources of stimulus change was obtained. Changes in transportational and contextual stimuli produced only a brief disruption in responding when reinforcement of leverpressing was continued. 相似文献
20.
Terry W. Belke 《Learning & behavior》2000,28(4):332-343
Previous research showed that sucrose and wheel-running reinforcement of leverpressing generate different response rate asymptotes. To investigate the basis of this difference, the present study assessed the role of inhibitory after-effects and excitatory stimulus effects on measures of responding in rats exposed to fixed-interval schedules that randomly produced either sucrose or wheel-running reinforcers. Different discriminative stimuli were associated with each reinforcer type. Inhibitory aftereffects and excitatory stimulus effects were assessed by the pattern of postreinforcement pauses and local response rates across the four different combinations of previous and upcoming reinforcer types: wheel-wheel, wheel-sucrose, sucrose-wheel, and sucrose-sucrose. Results showed that, regardless of the prior type of reinforcer, response rates were higher and pauses were shorter in the presence of a stimulus signaling sucrose reinforcement. This suggests that differences in response rate asymptotes generated by these qualitatively different reinforcers may have more to do with differences in excitatory stimulus effects than with inhibitory after-effects. 相似文献