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1.
Two groups of five rats each received a decreasing quantity of food reward, 14-7-3-1-0 .045-g food pellets, over successive runs in a runway. The interrun interval (IRI) separating runs within each of two daily pattern repetitions (trials) was 10 sec (short, S) or 4–5 min (long, L) and varied over four successive phases of training in the order indicated by the group names, that is, Groups SLSS and LLLS. Anticipation of the 0-pellet element developed more rapidly in Group SLSS than in Group LLLS, but did eventually occur at the long IRI. Anticipation was eliminated by the increase in IRI experienced by Group SLSS in Phase 2 and by the decrease in IRI experienced by Group LLLS in Phase 4. The results are discussed with reference to the effects of changes in stimulus context accompanying IRI shifts on retrieval of task-specific knowledge and with reference to the possible signal value established to IRI-specific stimuli.  相似文献   

2.
Rabbits (Oryctolagus cuniculus) were given either a 100% or a 50% reinforcement schedule in classical conditioning. Two groups received an aversive US (shock) and two groups received an appetitive US (water to the oral cavity). With parameter estimates for the two-phase model serving as the dependent variables, it was possible to define more precisely the effect of US omission with the intermittent reinforcement schedule. For the aversive preparation, the major effect of intermittent reinforcement was to increase the duration of Phase 1, a phase during which response likelihood remains constant at its initial value. Only a small proportion of subjects reflected the effect of US omission during Phase 2, the “learning” phase, this being a low operator limit following trials on which neither the CR nor the US occurred. The major effect of US omission for the appetitive preparation was in Phase 2, primarily a result of a minority of subjects having a low operator limit following trials on which neither the CR nor the US occurred. Many subjects required separate operators for trials on which the CR did or did not occur. The results were interpreted to pose difficulties for strength theories of conditioning, and the limitation implied for successful application of the Rescorla-Wagner theory are discussed. The implications of the data for response-contingent interpretations and for individual differences are also discussed.  相似文献   

3.
Contrast in consummatory behavior occurs readily when a less preferred substance follows a preferred substance. A previous experiment indicated that contrast in consummatory behavior may also develop when a less preferred substance precedes a preferred substance in brief daily exposures. In the present experiment, the same animals sometimes received 0.15% saccharin followed, 15 sec later, by 32% sucrose (.15–32) and sometimes received 0.15% saccharin followed by the same 0.15% saccharin solution (.15-.15). One solution pair was given each day, and the two conditions, .15–32 and .15-.15, occurred in alternation across days. The two different solution conditions were correlated with different cues. Saccharin intake from the first tube was lower when the second tube contained 32% sucrose than when it contained .15% saccharin, both in original discrimination training and following a reversal of the cue-solution pairings. These results support the conclusion that contrast in this situation is based on the anticipation of the impending 32% sucrose each day, rather than on a retrograde comparison with the 32% sucrose received the previous day. These data are considered in terms of Pavlovian conditioning outcomes when the CS is a stimulus with hedonic value.  相似文献   

4.
Two experiments investigating odor production and utilization in rats under the effects of Thorazine and Elavil injections, respectively, are reported. In Experiment 1, significantly slower speeds shown by the Thorazine-injected subjects indicated that this drug depressed performance. It is felt that depressed performance allowed these subjects to attend and respond to odor cues earlier in Phase 1 than did saline-injected control animals. Reversing the injection conditions (Phase 2) failed to disrupt already-established patterning. During the first phase of Experiment 2, Elavil-injected subjects failed to establish patterned responding, whereas such responding was readily established by saline-injected subjects. Reversing the injection conditions (Phase 2) resulted in the rapid development of double-alternation patterning by the subjects that were shifted from Elavil to saline and in the maintenance of such responding by the animals shifted from saline to Elavil.  相似文献   

5.
Separate groups of rats were trained and tested on asymmetrically and symmetrically reinforced successive delayed matching-to-sample (DMTS) or delayed discrimination (DD) tasks in Experiment 1. Each rat received training and testing on symmetrically reinforced DMTS and DD tasks in Experiment 2. The only difference between each task was that the rats had to respond correctly to a light or tone test stimulus, S2, if it matched a light or tone sample stimulus, S1, in DMTS, but could respond to either S2 if S1 had been a particular stimulus in DD. Only correct leverpresses were reinforced in the asymmetrically reinforced version of each task. Both correct presses and correct omissions were reinforced in the symmetrically reinforced version of each task. Response biases to leverpress during tests for delayed responding to S1 were reduced in both symmetrically reinforced tasks, but only in the DD task did such contingencies produce consistently poorer performance in responding to either S, in Experiment 1. Declines in accuracy of performance that occurred in both experiments were greater to the visual than to the auditory S1 only in the DMTS tasks with increased intervals between S1 and S2. A third experiment, in which rats had to respond to S2 if it matched S1 (DMTS) or if S2 mismatched S, (DMmTS), was carried out. Modality of S1 similarly affected accuracy of delayed responding in each task, as in the first two experiments. Methodological and theoretical implications of these results are discussed in terms of Honig and Thompson’s (1982) dual-process theory of working memory.  相似文献   

6.
An experiment was performed to investigate the relationship between sex, personality and learning style and French and German performance in secondary school pupils. 432 13–14 year old children (216 boys and 216 girls) whose mother tongue was English were given the Junior Eysenck Personality Inventory and Raven's Standard Matrices. Half of the subjects were then given three performance tests (comprehension, essay and prose translation), and the rest received three parallel German tests. The main findings were that, although pupils studied each language for the same time, German was easier than French, girls did better than boys, and that language performance increased with extraversion. The results were discussed in terms of their practical implications.  相似文献   

7.
The performance of four groups of mice of two genotypes (DBA/2J and C57BL/6J) was observed in two avoidance situations. Two groups, one of each strain, were given a maximum of 30 conditioning trials in an active avoidance situation followed by a maximum of 30 trials in a passive avoidance situation. The other two groups, one of each strain, were given passive avoidance conditioning first, followed by active avoidance conditioning. Positive transfer of training was observed in both genotypes for mice that received active avoidance conditioning prior to passive avoidance conditioning. Little or no transfer was observed from passive to active avoidance in either strain.  相似文献   

8.
Four groups of rats (n=6 per group) were trained in a runway on a serial learning task. Groups were treated identically in Phase 1, receiving two daily presentations of a five-element series consisting of decreasing numbers of .045-g food pellets over successive runs, for example, 14-7-3-1-0. All groups learned to anticipate, and run slowly to, the terminal 0-pellet element, behavior that has been attributed to learning of a less-than rule, stimulus-stimulus (S-S) associations, and knowledge of the serial position of items. In Phase 2, subjects were transferred to one of four test series: 20-14-7-3-0,20-7-3-14-0, 20-14-7-3-1-0, or 20-7-14-3-1-0. Anticipation was disrupted on the first two series, which maintained the integrity of serial position information and in the first case the less-than rule, but eliminated the terminal portion of the associative chain. Anticipation was unimpaired by transfer to either of the last two series. These series maintained the integrity of the terminal 3-1-0 portion of the associative chain but presented altered information about serial position, and in the last case also altered the less-than rule. The results, which supported the memory-discrimination model of rat serial learning, are discussed with reference to related transfer experiments in human serial learning.  相似文献   

9.
Illumination effects during steady-state performance of discrimination tasks in animals have been well documented, whereas research on illumination effects during acquisition has been largely ignored. Exceptions to this rule are Wasserman’s (1973) autoshaping experiments and Maki’s (1979) successive discrimination experiment. The present experiment investigated the effects of illumination changes on acquisition of a conditional discrimination—delayed matching-to-sample (DMTS). Pigeons were used in a between-groups design which factorially varied house-light illumination, on or off, during the presentations of DMTS stimuli, the delay interval, and the intertrial interval (ITI). DMTS performance over five blocks of sessions was the dependent variable. The major result was the three-way interaction of sessions, the intertrial interval, and the DMTS stimuli. Constant illumination resulted in the highest discrimination ratios over the last four blocks of sessions. A constant dark condition did not differ from a condition with dark ITIs and illuminated stimulus presentations or from a condition with illuminated ITIs and dark stimulus presentations. The proffered explanation of these data emphasizes the disruptive effects of stimulus changes and Wasserman’s (1973) cue localization hypothesis. The loci of the stimulus change and cue localization effect are suggested to be either at the beginning of a trial or at the end of a trial. A pretrial account emphasizes the role of stimulus changes on the encoding of the sample stimulus, and a posttrial account emphasizes the role of stimulus changes during consolidation processing.  相似文献   

10.
Empathy is theorized to improve the teaching effectiveness of teachers in urban and multicultural classroom settings. However, the field has few models useful for training and preparing teachers to cultivate empathy as a professional disposition. This study examines the academic, behavioral, and social/relational interactions of four White female high school teachers with their Black male students. Findings suggest that empathy, as a professional disposition applied by teachers to negotiate interactions with students, requires two phases of implementation. Phase 1 is the acquisition of new knowledge. Phase 2 is the strategic negotiation of that knowledge and interpretation of student feedback to make the necessary pedagogic adjustments in subsequent student–teacher interactions. Implications for teacher education and professional development are discussed.  相似文献   

11.
Previous research in directed forgetting in pigeons has focused on the effect of single forget cues (F-cues) interpolated within the retention interval in delayed matching-to-sample (DMTS). The present series of experiments focuses on the ability of a remember cue (R-cue) to cancel the effects of a previously presented forget cue both when the forget cue occurs within the retention interval and when the forget cue precedes sample presentation. In the first experiment, an R-cue decreased the effect of an F-cue within the same retention interval in successive DMTS if the R-cue immediately followed the F-cue, but not if the second cue was delayed until the end of the retention interval. In Experiment 2, the double-cue effect was extended to choice DMTS. In addition, when a novel stimulus replaced the R-cue in the double-cue probe trials, matching performance was not restored, indicating that through its conditioning history the R-cue had gained control over memory processes in a direction opposite to that of the F-cue. Experiment 3 presents evidence that presample R- and F-cues can also effectively gain control over matching performance. Matching to R-cued samples was superior to matching to F-cued samples. When F-cued samples were followed immediately by R-cues, matching performance was not restored to R-cue levels, suggesting differential encoding of the R-cued and F-cued samples.  相似文献   

12.
Squirrel monkeys were given either forward pairings of a bite-tube CS and shock US or backward pairings of these stimuli. Backward pairings produced stronger control of biting by the bite tube alone than did forward pairings. In a second experiment, subjects received backward pairings of US and CS with either a fixed ITI or a random ITI. Conditioned biting was obtained only when trials were presented with a fixed ITI. The magnitude of unconditioned biting was also significantly greater with the fixed ITI. It was argued that these results demonstrate that conditioning in this situation depends upon the degree to which biting predicts a relatively long shock-free period. When trials occur randomly in time, biting predicts no definite shock-free period; hence, it is not learned.  相似文献   

13.
The usual procedure in delayed-matching-to-sample (DMTS) experiments is that the most recently presented sample stimulus is correct on choice tests. The present paper reports two experments in which the first of two samples was always correct. Theories based on trace strength, such as the Roberts and Grant trace strength competition model, predict that such a procedure will yield below chance performance, because on the average the more recently presented stimulus will have the greater trace strength. In contrast, D’Amato and others have proposed that DMTS performance is mediated by a temporal discrimination process and, since either stimulus may act as S+ in a discrimination problem, monkeys should be capable of learning to choose either the secondor the first of two sample stimuli. Performance did not exceed chance in either experiment. The generality of these results is tentatively explored.  相似文献   

14.
The delayed matching-to-sample (DMTS) task was used in three experiments to investigate how pigeons code information about sample stimuli. In all experiments, each trial consisted of a signaled presentation of a sample stimulus for a fixed duration followed, after some delay, by the presentation of three comparison stimuli. After incorrect first choices, the bird was allowed a second choice between the remaining two stimuli. It was found, in Experiment 1, that the probability of a second choice error declined with increasing sample duration. This result is consistent with a gradual short-term memory encoding process but not with a simple two-state all-or-none process. In the second experiment, it was found that the distribution of first-choice errors was affected by the particular sample occurring on a trial. This result is inconsistent with a two-stage discrete state memory/attention model based on the assumption that encoding of the sample and attention to the comparison stimuli are both independent all-or-none processes. The third experiment involved symbolic DMTS, in which the sample stimuli varied along a dimension different from that along which the comparison stimuli varied. With increasing delay between sample and comparison stimulus presentations, the pigeons were more likely to confuse test stimuli than to confuse sample stimuli. The results of these experiments lead to the conclusion that pigeon DMTS performance depends on a gradual encoding process in which a representation isomorphic with the test stimuli is generated and maintained.  相似文献   

15.
This study examined how 30 minutes of search time on the Web affected students’ essay scores in response to a writing prompt. Expository essays were obtained from 49 fourth- and fifthgrade students enrolled in an elementary school in Virginia, in the United States. Students were placed by random assignment into three groups with the same writing prompt for all three groups. Data analyses using ANOVA indicate that there was statistical significance in two components of writing. The group that received instruction on using the Internet to conduct research in the prewriting phase outperformed the control group in two areas: the total essay score (p=.053) and usage/mechanics (p=.028). The study also produced effect sizes ranging from small to large when the Internet users were compared to the control group. Implications for the future of Internet use in the school system are discussed.  相似文献   

16.
Short-term memory (STM) for haptic information was examined in a delayed matching-to-sample (DMTS) task. Three rhesus monkeys were tested in DMTS with all possible combinations of different-size spheres and cubes as the sample and comparison stimuli. The results showed that the decrease in percentage correct as a function of the retention intervals was relatively independent of the size and shape of the sample and comparison stimuli. In general, at each retention interval, percentage correct was higher when the (1) comparison stimuli differed in both size and shape than when the comparison stimuli differed in only size or shape, (2) size differences between the comparison stimuli increased, and (3) samples were spheres rather than cubes. This pattern of results suggests that dimensions of the haptic stimuli influenced discrimination but had little effect on the animals’ STM. In Experiment 2, the same three monkeys responded to the sample and comparison stimuli with the same hand or responded to the sample with one hand and the comparison stimuli with the opposite hand. The decrease in percentage correct across retention intervals was comparable for all possible hand combinations. These results suggest that the loss of information from STM is comparable when the sample and comparison stimuli are both felt with the same hand or with opposite hands.  相似文献   

17.
Rats were trained on a series of reversals of a successive discrimination in which the percentage of S+ trials ending in food was varied. Changes in the discrimination index occurred more slowly with 50% reinforcement than with 100% reinforcement when the number of training trials was equated across conditions, but were approximately invariant when the conditions were equated with respect to the number of obtained reinforcements. Presentation of free reinforcement during the intertrial intervals reduced the overall rate of discrimination acquisition, but left this invariance unaffected. Invariance in reinforcements necessary to attain acquisition also occurred when different discriminations correlated with different percentages of reinforcement were intermixed within experimental sessions. The failure of the invariance effect to be disrupted by either manipulation suggests that previous accounts of the invariance effect in terms of “comparator” models of conditioning (e.g., Gibbon & Balsam, 1981) are inadequate.  相似文献   

18.
19.
Although over 15 years have passed since Witt (1990) Witt, J. C. 1990. Collaboration in school based consultation: Myth in need of data. Journal of Educational and Psychological Consultation, 1(3): 367370. [Taylor & Francis Online] [Google Scholar] noted that no empirical evidence exists to support the contention that a collaborative approach to consultation leads to more positive outcomes than a hierarchical or expert driven approach, this issue generally remains unaddressed (Schulte & Osborne, 2003 Schulte, A. S. and Osborne, S. S. 2003. When assumptive worlds collide: A review of definitions of collaboration in consultation. Journal of Educational and Psychological Consultation, 14(2): 109138. [Taylor & Francis Online], [Web of Science ®] [Google Scholar]). While the literature documenting the benefits of consultation has continued to grow, a true head-to-head comparison has not been conducted. The purpose of the present study was to directly address Witt's call by empirically examining the impact of two consultation styles on a critical variable, practitioner treatment integrity. It was hypothesized that the involvement of practitioners in all aspects of intervention design would increase their level of treatment integrity. Two single-subject experiments using multiple baseline across subjects designs were used to examine the difference in level of treatment integrity for an imported, expert-driven intervention and a partnership-designed intervention. The first experiment was divided into three phases: (a) Phase I, Expert-driven Model; (b) Phase II, Treatment Integrity Intervention; and (c) Phase III, Partnership Model. The second experiment presented the three phases in reverse order to address the possibility of presentation effects: (a) Phase I, Partnership Model; (b) Phase II, Expert-driven Model; and (c) Phase III, Treatment Integrity Intervention. In general, the five participants who completed the three phases of the experiments demonstrated higher levels of treatment integrity during the partnership phase. Overall, the results suggest that engaging with consultees in a collaborative approach may increase the level of integrity with which the intervention is applied.  相似文献   

20.
Sixteen reproductively matureAplysia dactylomela were observed in a unidirectional stream under each of four conditions: sea water only, one sea hare, six sea hares, and a copulating sea hare pair. Streams containing conspecific stimulation were significantly more effective in eliciting a positive taxis towards the stimulus source. A copulating pair was not different from one or six animals in producing the approach. The sea hares showed a distinct final head orientation to six sea hares when compared with sea water only; final orientation did not differ in any other comparison.  相似文献   

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