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1.
Modes of responding in simultaneous and successive discrimination problems were investigated using a bidirectional transfer procedure. Rats receiving training on a simultaneous discrimination problem were transferred to successive discriminations. Rats trained on a successive problem were transferred to simultaneous problems. The transfer problems were either compatible or incompatible with the response mode present during training. The results suggest that a single response mode may underlie the solution of both simultaneous and successive discrimination problem.  相似文献   

2.
Pigeons were trained with one eye covered on each of two types of visual discriminations. They then were tested for interocular transfer with the previously covered eye. Transfer was shown by every pigeon trained on a simultaneous discrimination, while lack of transfer was shown by thesesame pigeons when trained on a spatial conditional (successive) discrimination. As opposed to the pigeon, animals with a larger proportion of ipsilateral (uncrossed) retinal fibers (e.g., cats) do show transfer of both discrimination problems. This difference in the decussation of the optic pathways may be a critical variable in interocular transfer in vertebrates. Furthermore, these studies demonstrate that interocular transfer in the pigeon depends upon the experimental paradigm.  相似文献   

3.
Although considerable attention has been given to interactions between events serving as the positive (S+) and negative (S−) stimuli in successive discriminations, there has been little study of similar interactions in simultaneous discriminations. We propose that in a simultaneous discrimination, given what is typically relatively little experience with the consequences of responding to the S−, some of the value of the S+ transfers to the S− with which it was paired. Furthermore, the mechanisms responsible for this transfer of value appear to be the higher order Pavlovian association between the S− and the S+, as well as within-event associations between them. Although in typical simultaneous discriminations, negative value does not appear to transfer from the S− to the S+, when adequate experience is provided with the S−, contrast typically develops, reducing the value of the S− (negative contrast) and enhancing the value of the S+ (positive contrast). This model of stimulus interactions has implications not only for simple simultaneous discrimination learning, but also for research using combinations of discriminations (e.g., transitive inference in animals and humans). This model may also have implications for a number of human social psychological phenomena.  相似文献   

4.
The present research tested the generality of the “work ethic“ effect described by Clement, Feltus, Kaiser, and Zentall (2000). In Experiment 1, we trained 10 pigeons on a pair of either simultaneous or successive discriminations. One discrimination followed a high-effort requirement (20 pecks to the center key) and the other followed a low-effort requirement (1 peck). Contrary to Clement et al.’s results, we found that preferences between the S+ and S stimuli in transfer tests depended on the event that initiated the trial: Pigeons preferred the stimulus from the baseline discrimination whose initiating event was most dissimilar from that preceding the test trial. Preferences were similar but less extreme in the successive condition. In Experiment 2, we investigated whether test preferences depended on the amount of training. A total of 12 pigeons were trained on a pair of simultaneous discriminations, except that test sessions were scheduled after every three baseline sessions. Preferences increased across test sessions but were similar to those in Experiment 1. Together with Vasconcelos, Urcuioli, and Lionello-DeNolf (2007a), our study represents a second failure to replicate Clement et al.’s work ethic effect. The finding that preference depends on the event that initiates the test trial suggests that choice probes may not provide unambiguous assessments of stimulus value.  相似文献   

5.
THE METACOGNITIVE performance of four groups of students was examined. The students' processes of visual analysis and discrimination of real-life pictures were used to measure metacognition. There were 61 participants: 18 hearing students, 18 deaf and hard of hearing students, 16 students with mild mental disabilities, and 9 students with physical disabilities. Analysis revealed no significant differences among hearing students, deaf and hard of hearing students, and students with physical disabilities. The performance of these three groups of students was significantly better than the performance of students with mild mental disabilities. It appears that students with mild mental disabilities encountered difficulties with pictures that required complex visual analyses and discriminations. These difficulties were manifested in a form of deficient simultaneous visual processing along with a low level of knowledge acquisition.  相似文献   

6.
Only a limited number of species have been found capable of generalized matching-to-sample (MTS) after exposure to relatively few training exemplars. We trained a juvenile, experimentally naive California sea lion (Zalophus californianus) in MTS, using a pair of three-dimensional objects as samples. Successful matching to a criterion of 90% correct or better over 2 successive sessions was attained in 12 sessions (269 trials and 70 errors). Two subsequent “partial” transfer tests, in which each of the two training objects was paired with a novel test object, and four additional transfer tests, all with novel objects, were presented following training. An 80% performance criterion over 2 successive sessions was reached, or closely approximated, in from 2 to 4 transfer sessions for all transfer tests; errors to criterion tended to be reduced across the successive novel transfer tests and were as few as five during the final two tests; and performance on the first 48 trials of the last two novel transfers was not significantly different from a near-ceiling level baseline performance measure. Neophobic responses of the sea lion to new objects precluded an unbiased evaluation of immediate (Trial 1) transfer. The sea lion’s short-term memory for sample objects was also measured. Matching performance was maintained at a level of 78% correct responses or better for delays through to 45 sec after removal of the sample object. At a 58-sec delay, the longest tested, performance declined to 69% correct responses. These retention levels are only somewhat below levels reported for dolphins and nonhuman primates tested on visual delayed MTS, but they are above levels typically reported for pigeon subjects.  相似文献   

7.
Three experiments with rat subjects examined the development of simultaneous and serial feature-positive discriminations in appetitive conditioning. In Experiment 1, reinforced presentations of a simultaneous light-tone compound were intermixed with nonreinforced presentations of either the light or the tone. The compound stimulus acquired conditioned behaviors of a form characteristic of the predictive feature alone; the element common to reinforced and nonreinforced trials did not evoke conditioned behavior. In Experiment 2, reinforced presentations of a serial light-trace-tone compound were intermixed with nonreinforced tone-alone presentations. The light feature stimulus acquired conditioned behaviors characteristic of visual CSs. The tone stimulus, common to reinforced and nonreinforced trials, evoked conditioned behaviors characteristic of auditory CSs, but only when preceded by the light. In Experiment 3, variations in the interval between the light and tone on reinforced trials had little effect on responding to the light CS but substantially altered the pattern of responding to the tone CS. These results suggested that simultaneous and serial feature-positive discriminations may be solved differently. Performance in simultaneous feature-positive discriminations may be determined solely by associations between the feature stimulus and the reinforcer, but performance in serial discriminations may also involve the acquisition of a conditional cue function to the feature.  相似文献   

8.
During simultaneous discrimination training, there is evidence that some of the value of the S+ transfers to the S?. When the value of the S+ is altered outside the context of the simultaneous discrimination, two very different predictions are made concerning its effect on its S?, depending on whether one views the S+ as an occasion setter or as a stimulus capable of transferring value. In four experiments, pigeons were trained with two similar simultaneous discriminations, A+B? and C+D?, and two single-stimulus trial types, A and C, (in which A always had greater nominal value than C). According to value transfer theory, on test trials, B should always be preferred over D, because B and D should be affected by the net values of A and C, respectively. According to an occasion setting account, however, D should be preferred over B because the presence of D signals a higher probability of reinforcement for responding to C than when C is alone, and/or the presence of B signals a lower probability of reinforcement for responding to A than when A is alone. In all four experiments, the pigeons preferred B over D, a result consistent with value transfer theory. Thus, an S? can acquire value from an S+ even when that value is conditioned in a “context” different from that of the simultaneous discrimination.  相似文献   

9.
The effects of the intertrial interval (ITI) on learning and performance in Pavlovian appetitive serial feature positive (SFP) discriminations were examined in three experiments with rats. With longer ITIs, acquisition was more rapid, and there was less transfer of the feature’s behavioral control to a separately trained target cue, suggesting that longer ITIs encouraged the use of an occasion setting strategy. Behavior was also affected by discrimination-specific ITIs. Rats were trained with two SFP discriminations. The overall ITI was held constant, but the intervals between trials of one discrimination were varied by intermixing different numbers of trials from the other discrimination. Learning was more rapid when the intervals between trials of a single discrimination were longer. A sequential analyses showed that performance on a trial was impaired when it was preceded by a trial that included the same target cue but with the opposite trial outcome. The results are discussed in the frameworks of proactive interference effects and deletion-comparator processes (Cooper, Aronson, Balsam, & Gibbon, 1990.)  相似文献   

10.
In Experiment 1, pigeons were trained on two feature-positive discriminations. A transfer test examined whether the feature from one discrimination enhanced responding to the target from the other. Transfer was obtained, but it was incomplete; the feature produced less responding to the transfer target than to its own. Experiments 2 and 3 examined whether this attenuation of responding was the product of generalization decrement induced by the novel combination of feature and target on transfer trials. Birds were trained on a pair of pseudo-occasion-setting discriminations in which each target was reinforced whether or not it was preceded by its feature. In a subsequent test, there was no loss of responding when novel combinations of features and targets were introduced; on the contrary, responding was, if anything, enhanced in this condition. This suggests that imperfect transfer is not due to generalization decrement but to the fact that an occasion setter is specific to its target stimulus.  相似文献   

11.
Rabbits were trained in either positive patterning (AX+, A−, X−) or negative patterning (A+, X+, AX−) using one of four intervals between the onset of A and the onset of X on AX trials. These intervals were 0, 800, 2,400, and 5,600 msec. In each task, all groups acquired an appropriate pattern of discriminative responding. Following acquisition, all rabbits were tested with the four different A-X intervals. All positive patterning groups showed an excitatory gradient, in which the highest level of responding occurred at the interval used in training. Conversely, all but one of the negative patterning groups showed an inhibitory gradient, in which the lowest level of responding occurred at the interval used in training. The one exception was the negative patterning group trained with simultaneous AX stimuli (0 msec), which showed a low, broad gradient, indicating transfer of inhibition across all the intervals. The results are discussed with respect to temporal encoding mechanisms and accounts of conditional discriminations.  相似文献   

12.
Cross-modal transfer of learning between black/white and rough/smooth discrimination tasks was studied in a two-choice maze procedure in which the stimuli for both discriminations were located on the floor of the maze. Rats were trained initially with cues of one modality and then given transfer training with cues of the second modality. The amount of transfer produced by two criteria of learning, 9 correct responses in 10 trials and 18 correct responses in 20 trials, was also studied. Bidirectional cross-modal transfer of learning was demonstrated more clearly with the more stringent learning criteria. These positive transfer effects appeared primarily to be the result of general transfer processes.  相似文献   

13.
In two experiments, we investigated the impact of odor preexposure treatments on the acquisition of an olfactory discrimination in dogs. In the first experiment, four groups of dogs were each given five days’ odor-exposure treatment prior to discrimination training. Dogs in the exposure group were exposed to anise extract (S+) for 30 min daily. Dogs in the Pavlovian-relevant pairing group received six daily delayed-conditioning trials to the same S+. The Pavlovian-irrelevant pairing group received conditioning trials to almond extract (S'). Dogs in the control group received no pretreatment. All of the dogs were then trained to detect S+ from a background pine odor (an AX-vs.-X discrimination). The Pavlovian-relevant pairing group acquired the odor discrimination significantly faster than all of the other exposure and control groups, and the remaining groups acquired the discrimination at the same rate as the no-exposure control group. In a second experiment, we extended these results to a within-subjects design using an AX-versus-BX discrimination. Six dogs were simultaneously trained on two different odor discriminations, one discrimination in which the S+ was previously Pavlovian conditioned, and one discrimination in which the S+ was novel. All of the dogs learned the odor discrimination with the previously conditioned S+ faster than they learned the novel odor discrimination, replicating the results of Experiment 1, and demonstrating that familiarity in the form of Pavlovian conditioning enhances odor-discrimination training. The potential mechanisms of the facilitated transfer of a Pavlovian conditioned stimulus to discrimination training are discussed.  相似文献   

14.
Minimal procedures for the demonstration of transitive inference (TI) in animals have involved the training of four simultaneous discriminations: for example, A+B?, B+C?, C+D?, and D+E?, followed by the demonstration of a preference for B over D on test trials. In Experiment 1, we found that TI in pigeons can be found with successive training involving A+B?, B+C?, A+C?, C+D?, D+E?, C+E?, and A+E?. In Experiment 2, we found that demonstration of TI did not require inclusion of experience with the nonadjacent stimulus pairs (A+C?, C+E?, A+E?). Experiment 3 provided a test of value transfer theory (VTT; Fersen, Wynne, Delius, & Staddon, 1991). When pigeons were trained with stimulus pairs that did not permit the transitive ordering of stimuli, but did permit the differential transfer of value (e.g., A+B?, C?E+, C+D?, & A+E?), preference for B over D was still found. Analyses of the relation between direct experiences with reinforced and nonreinforced responding and stimulus preferences on test trials failed to support a reinforcement-history account of TI.  相似文献   

15.
In two experiments, the effects of feature identity in operant serial feature-positive discriminations were examined with rats. Rats were trained with two serial feature-positive discriminations (F1 → T1+/ T1? and F2 → T2+/ T2?), in which different operants were reinforced with delivery of a sucrose solution during two auditory target cues (T1 and T2). The features (F1 and F2) were two visual cues, two flavored sucrose solutions, or one visual cue and one sucrose solution. Transfer of a feature’s control to the target of the other discrimination was observed only when the features were from the same modality. When observed, transfer responding was of the form originally trained to the target, rather than the feature, and was preserved after feature extinction. Control groups showed that the differential transfer was not solely the consequence of differential feature generalization. Implications for theories of occasion setting are discussed.  相似文献   

16.
In two experiments, rats were trained on a successive go/no-go discrimination problem in the runway in which the positive (S+) and negative (S?) discriminanda were differentiated by the presence or absence of a distinctive feature. The feature in Experiment 1 was a series of flashing lights over the runway. In Experiment 2, the feature was a pretrial reinforcement (Phase 1), or pretrial reinforcement versus pretrial nonreinforcement (Phase 2). The feature signaled S+ trials in feature-positive (FP) groups and S? trials in feature-negative (FN) groups. The original discrimination was reversed in Phase 2 of both experiments. With the exception of the pretrial nonreinforcement groups in Experiment 2, there was an asymmetry in discrimination learning in both phases of both experiments favoring superior discrimination learning by FN subjects over FP subjects, a feature-negative effect. Implications of the results for an information processing account of asymmetries in learning feature discriminations are discussed.  相似文献   

17.
This study explored the visual discrimination learning ability of fire-bellied toads (Bombina orientalis). Two groups of toads were trained in a simultaneous visual discrimination task involving video footage of either black crickets on a white background (black-cricket toads) or white crickets on a black background (white-cricket toads). Fifteen widely spaced acquisition trials were followed by 12 reversal trials. Successful learning was observed by decreased incorrect snapping and reduced latency to snap at the correct stimulus (S+) during acquisition; however, white-cricket toads executed significantly more incorrect snaps than did black-cricket toads. Both groups of toads could master the reversal task as measured by latency to snap at S+, but not as measured by the proportion of incorrect snaps. Despite the stronger potency of the black-cricket stimulus, the results showed that toads can learn a simultaneous discrimination task and a reversal of its contingency. This elaborate form of learning appears to be conserved among vertebrates.  相似文献   

18.
In four experiments, rats were trained on different patterning discriminations before being tested with compounds composed of novel combinations of the trained stimuli. In Experiment 1, rats were trained on a negative-patterning schedule (A+ B+ AB-) intermixed with reinforced presentations of a second compound (CD+). On a subsequent test, the rats responded more to two novel compounds, AC and BD, than to A and B, but less than to CD. In Experiment 2, rats were trained on two concurrent negative-patterning discriminations (A+ B+ AB-, C+ D+ CD-). On test, they responded more to AC and BD than to AB and CD, but less than to the single stimuli. In Experiment 3, rats were trained on two concurrent positive-patterning discriminations (A-B- AB+, C- D- CD+). On test, their response rates to AC and BD were not different from the response rates to the trained compounds (AB and CD). Finally, in Experiment 4, rats were trained on a positive- and negative-patterning discrimination concurrently. Once again, on test, response rates to AC and BD were not different from responding on reinforced trials of the trained discriminations (A+, B+, and CD+). We discuss the implications of these findings for elemental and configural models of stimulus representation.  相似文献   

19.
Nine newborn chicks were trained on a successive, red-green discrimination task. At the start of discrimination training, the intensity of the green light (S?) was slowly faded in for six chicks and was presented at full intensity for the remaining three. While meeting the response criterion for errorless learning, the chicks conditioned with the fading procedure made five times fewer errors than the full-intensity group. It was concluded that preexperimental error experience is not a necessary condition for the development of errorless learning.  相似文献   

20.
Identity concept formation was tested in a harbor seal using a visual multiple-choice matching-tosample task. The seal was first trained on a two-alternative matching task. After criterion (≥80% correct choices in two successive sessions) was reached with two sets of two stimuli (Figure 3, Blocks A and B), stimulus sets were enlarged to six objects (Blocks C-G). After the seal reached criterion immediately with two successive sets (Blocks F and G), multiple-choice matching was introduced, first using stimulus sets of four familiar objects (Blocks H-M). After the seal reached the criterion immediately with two successive sets (Blocks L and M), completely new objects were used in two further stimulus sets (Blocks N and O). The seal immediately applied the matching rule in all four sessions (≥80% correct choices). In two further sessions with problems composed of all 38 familiar stimuli, the seal again reached the criterion (Block P). In the final, transfer session, 20 new problems were composed of 80 unknown stimuli (Block Q). The seal immediately applied the matching rule in these one-trial tests, showing that harbor seals can conceptualize complex visual information.  相似文献   

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