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1.
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   

2.
Squirrel monkeys (Saimiri sciureus) and titi monkeys (Callicebus moloch) were tested in three two-choice visual discrimination experiments. Although, on average, squirrel monkeys performed more accurately than titis, the range of response accuracies in the two species overlapped considerably in all three experiments and changes in response accuracy over test sessions and across experiments were similar in the two species. Thus, the species shared several behavioral characteristics expected of New World primates in this setting. Squirrel monkeys’ performance appeared to be more affected than titis’ by task difficulty, and squirrel monkeys were individually less consistent than titis. These differences were associated with higher activity levels and briefer overt attentiveness to the repetitive task in squirrel monkeys and, conversely, with lower activity levels, slower working speeds, and sustained interest in the task in titis. The associated differences are discussed in relation to each species performance in other laboratory settings and the characteristic patterns of foraging and use of space in nature.  相似文献   

3.
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   

4.
Utilization and dominance of physically separate redundant-relevant cues were measured in albino rats under moderate (18 h/day) or high (23.5 h/day) water deprivation. Cues were located on goal doors (brightness) and the floor (texture) in a two-choice discrimination apparatus. Three experiments were carried out with the following paradigms: incidental cue, redundant-relevant cue discrimination, and optional shift discrimination. Deprivation did not affect rate of acquisition of initial discrimination or cue dominance. Cue utilization, however, was inversely related to deprivation in redundant-relevant cue and optional shift discrimination tasks. These effects were limited, however. Over-training on the redundant-relevant cue task eliminated the effect. Within the optional shift situation, only animals that initially acquired a texture cue discrimination were affected by deprivation. Other factors affecting cue utilization in these experiments were also described and discussed.  相似文献   

5.
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   

6.
TwoLemur catta were tested in a WGTA on three two-choice color discrimination problems involving paired comparisons of red, green, and blue. Four illumination combinations between the two discriminanda served to make brightness irrelevant, hue being the only salient cue. All color problems were learned within criterion limits of 21 out of 25 correct choices during 16 consecutive test sessions, indicating good color vision for this diurnal prosimian.  相似文献   

7.
Experiments 1A and 1B used a taste-aversion procedure with rats to demonstrate that exposure to easily discriminated flavors along a dimension (1 % and 10 % sucrose) can facilitate learning a subsequent hard discrimination (4 % and 7 % sucrose) when one of those flavors is paired with illness. Experiment 1A compared the effects of preexposure to the easily discriminated flavors against exposure to the same stimuli used in the discrimination training or no exposure at all. Experiment 1B replicated the conditions in Experiment 1A, with 2 additional days of training and unrestricted access to the flavors on CS+/CS– trials in discrimination training. Contrary to findings with multidimensional stimuli (Scahill & Mackintosh, Journal of Experimental Psychology: Animal Behavior Processes, 30, 96–103, 2004; Suret & McLaren, The Quarterly Journal of Experimental Psychology, 56B, 30–42, 2003), we found that preexposure to the easily discriminable stimuli varying along a single dimension of sweetness facilitated subsequent discrimination training over the other conditions in each experiment. We discuss the results in terms of the ideas presented by Gibson (1969) and Mackintosh (Psychological Review, 82, 276–298, 1975) and in terms of hedonic variables not considered by theories of perceptual learning.  相似文献   

8.
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   

9.
Three groups of college students were given instructions using different testing techniques to determine whether the superior performance obtained with Programmed Student Achievement (PA) was due to a Hawthorne Effect. PA students, operating under the consequence of failing the course if they failed to evidence criterion performance (100% mastery) on weekly quizzes, exhibited superior performance, relative to control groups, on the weekly quizzes and on an unannounced retention test. The results seem to preclude any attempt to interpret the effectiveness of Programmed Student Achievement on the basis of a Hawthorne Effect.  相似文献   

10.
Newly hatched ducklings were imprinted to one stimulus and then given prolonged visual exposure to a second discriminable stimulus. Filial behavior toward the second stimulus developed more slowly when the original imprinting stimulus was occasionally presented during exposure to the second stimulus than when the original stimulus was withheld during such exposure. Results were interpreted in terms of a possible motivational aftereffect following presentations of the original imprinting stimulus.  相似文献   

11.
The concept of “Home Learning Environment” (HLE) covers activities in a family providing intellectual stimulation for a child, such as reading to him or her or visiting libraries. Numerous studies have shown an association between HLE and children's cognitive development. In this longitudinal study, we focus on HLE as a predictor for children's behavioral development, namely, for later symptoms of attention-deficit hyperactivity disorder (ADHD), controlling for relevant aspects like socioeconomic status (SES), or television viewing behavior. We analyzed the development of ADHD symptoms from kindergarten to the end of grade 2 and possible associations with HLE, SES, and television exposure, using a German community sample (N?=?924). Results indicated that ADHD symptoms were negatively and significantly correlated to HLE for all five measurement points as well as to SES (except T4) and to television exposure for T1 to T4. Observing later development, only early HLE but not SES or television exposure served as a significant predictor for ADHD symptoms at school, when age, sex, and ADHD symptoms in kindergarten were controlled for. A structural equation model showed that HLE acted as a mediator between SES and later ADHD symptoms. Our results highlight the importance of the concept of home learning environment also for children's behavioral development. As a consequence, parents should be supported in offering their children a more favorable learning environment.  相似文献   

12.
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   

13.
The present study investigated the strategies involved in the Kohs Block Design task from a cognitive point of view. One purpose was to improve the classical distinction between syncretic and analytic strategies. An other goal was to determine whether subjects show the same strategies according to their field dependence level. Finally, we analysed the way the subjects described their own strategies in order to assess their metacognitive skills. The subjects (17 year-old pupils) were first given a field dependence proof (G.E.F.T.), then the Kohs Block Design task and finally were interviewed about their strategies. Each pupil was tested individually and videotaped. The strategies were drawn by four indicators. The results indicated three strategies: syncretic, analytic and synthetic strategies. The degree of field dependence clearly distinguished the strategies in the Block Design task: more independent the subject is, more he used a synthetic strategy. Finally, the subjects’ verbalizations were more closely connected with their behaviours. In a general way, the subjects appeared to be steady in the use of a particular strategy.  相似文献   

14.
15.
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   

16.
Albino rats were trained to respond on a multiple variable-interval (VI) shock-avoidance schedule, where VI responses were reinforced on one bar, and shock-avoidance responses were reinforced on another in alternating components. Tone-shock pairs were superimposed upon the VI components, and conditioned suppression was obtained. These results are in opposition to those obtained when stimulus-shock pairs are superimposed upon baselines in Ss with shock-avoidance histories where a single manipulandum has been used for both schedules.  相似文献   

17.
This paper is a version of the sixth ECTJ/ERIC-IR Young Scholar Paper, an annual award initiated to stimulate writing by young professionals in the field of instructional technology. Preparation of the paper was supported by the ERIC Clearinghouse on Information Resources at Syracuse, NY 13210.  相似文献   

18.
19.
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   

20.
Stumptailed monkeys (Macaca arctoides) were given two two-choice line-discrimination problems in which the lines were presented either alone or embedded in a patterned context that was the same in all cases. When the stimuli were a left- and a right-tilting line, the addition of the context significantly improved performance, as measured by frequency of correct choice responses. It also decreased choice response latency, duration of visual fixations, and frequency of scanning back and forth between the two stimuli. When the stimuli were a horizontal and a vertical line, the addition of the context had the opposite effect on all the performance measures. These results are very similar to those found with adult and infant humans when given the same stimuli. They suggest that the pattern perception of monkeys, like that of humans, involves top-down or holistic processing of incoming visual information.  相似文献   

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