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1.
Eye movements of two stump-tailed monkeys were measured during performance on an easy and a difficult brightness discrimination problem with and without a relatively long fixation required at the beginning of each trial for purposes of calibration. The duration of an individual fixation of the discriminative stimuli was unrelated to most of the variables that were examined, including problem difficulty, response outcome, whether the S+ or the S? was fixated, and presence or absence of a long fixation at the beginning of a trial. Duration of fixation increased markedly, though temporarily, following reversal of the hard problem. The animals tended to do a minimal amount of scanning of the discriminative stimuli and to fixate most frequently on S+ before responding. In general, the results did not support an account of observing behavior in terms of conventional reinforcement. 相似文献
2.
Previous work has shown that when a delay of reward (DOR) is introduced into a well-learned discrimination, even gradually, discriminative performance deteriorates and, with moderately long DORs, does not recover with practice. The present experiment assessed whether the decrement in performance was due to an associative loss or to a decline in the incentive value of the reward object caused by the DOR. Cebus monkeys were trained on a simple visual discrimination and tested with either a DOR or an identical delay period which preceded the appearance of S+ and S? (“predelay” trials); reinforcement on predelay trials was immediate. On half of the daily trials, the animals were given the option of choosing either the DOR or the predelay trial. The duration of the delay was increased gradually until terminal delays of 32 to 128 sec were reached. All four animals maintained almost errorless performance on predelay trials; in contrast, their error rate reached 36% on DOR trials. Surprisingly, none of the animals learned to choose predelay over DOR trials. Both results were interpreted in terms of the incentive loss hypothesis. 相似文献
3.
E. J. Capaldi 《Learning & behavior》1979,7(1):63-68
In this investigation, which employed rats in a runway, discriminative responding consisted of faster running on the reinforced than on the nonreinforced trials of either the 4NR or R4N schedule, both schedules containing fixed, repeated sequences of nonreinforced and reinforced trials. Under the 4NR schedule, four nonreinforced trials preceded a reinforced trial each day, and under the R4N schedule, a reinforced trial was followed by four nonreinforced trials each day. The major finding obtained was that under the 4NR schedule, discriminative responding was improved very substantially by a shift to extinction. Rats maintained on the 4NR schedule did not show improved discriminative responding, nor did discriminative responding improve in extinction following training under either the R4N schedule or a schedule of consistent reinforcement. Latent discrimination learning was defined as discriminative responding which fails to reflect adequately the amount of discrimination learning accomplished. The present findings demonstrate latent discrimination learning for regular schedules of partial reinforcement, something already demonstrated for brightness differential conditioning and possibly DRL schedules, as well. 相似文献
4.
Pigeons served in two experiments in which responding on an observing key converted a two-component mixed schedule to the corresponding multiple schedule of reinforcement. Presentation of the stimulus correlated with the more valued component was faded out (probabilistically) over sessions, so that ultimately an observing response produced only the stimulus correlated with the less valued component. Observing was well maintained after a fading procedure when a stimulus was produced by a single response, regardless of whether the less valued stimulus was associated with food or with extinction (Experiment 1). However, observing was not well maintained after a fading procedure when a stimulus was produced according to an intermittent schedule (Experiment 2). Taken together, the results of the two experiments suggest that the absence of an exteroceptive stimulus change after a single response may become discriminative in its own right for the more valued component, and that the fading procedure is an effective means of promoting this discrimination. However, if observing responses produce a stimulus change according to an intermittent schedule, then the absence of a stimulus change after a response is correlated with both components. Under these conditions, the absence of stimulus change is not discriminative for either component, even with fading, and observing is not maintained. 相似文献
5.
Individual Differences in Infant Visual Attention: Are Short Lookers Faster Processors or Feature Processors? 总被引：2，自引：1，他引：2
John Colombo D. Wayne Mitchell Jeffrey T. Coldren Laura J. Freeseman 《Child development》1991,62(6):1247-1257
Individual differences in the duration of infants' visual fixations are reliable and stable and have been linked to differential cognitive performance; short-looking infants typically perform better than long-looking infants. 4 experiments tested the possibility of whether short lookers' superiority on perceptual-cognitive tasks is attributable to attention to the featural details of visual stimuli, or simply to differences in the speed or efficiency of visual processing. To do this, the performance of long- and short-looking 4-month-olds was examined on separate discrimination tasks that could be solved only by processing either featural or global information. The global task was easier than the featural task, but as the amount of time allotted for infants to solve either type of task was decreased, short lookers' performance was superior to that of long lookers. These results thus lend support to a speed or efficiency of stimulus processing interpretation of infant fixation duration. 相似文献
6.
Compared with their performance with localized (on-key) visual stimuli, pigeons are notoriously poor at performing go/no-go discriminations when keypecking for food in the presence of auditory discriminative stimuli. The difference might reflect the fact that an aversive visual onkey stimulus signaling nonreward can be escaped by looking away and not pecking, which contributes to the measure of good discriminative performance, while an auditory stimulus cannot be escaped. In Experiment 1, discriminative performance was significantly improved by providing pigeons with a response incompatible with keypecking by which they could escape a tone S+ and a tone S?. However, the pattern, frequency, and duration of escape responses were found to be insufficient to explain the improvement. In Experiment 2, it was found that the capacity to escape only S+ or only S? enhanced discriminative performance as much as the capacity to escape both. It is theorized that the Pavlovian relationship between the absence of the discriminative stimuli and the nonoccurrence of food might transfer to the instrumental relationships learned in a go/no-go discrimination. The possibility that intermittent stimuli command more attention than continuous stimuli is also considered. 相似文献
7.
Tactual discriminative abilities out of the control of vision are studied in 5-month-old infants, and compared with their visual discriminative abilities. The relevance of a habituation/reaction to novelty procedure in the tactual modality is tested. An infant control procedure is used in both modalities on 2 independent samples of 32 infants each. Habituation and discrimination occur tactually as well as visually, the duration of holds decreasing more than the duration of looks. Accumulated holding time is 3 times longer than accumulated looking time. Analogies and discrepancies between tactual and visual habituations are discussed, and the problem of sensory dominance is raised. Such results are basic to studies on cross-modal transfer, from vision to touch as well as from touch to vision. 相似文献
8.
Temporal parameters were varied in two different observing response procedures. In Experiment I, concurrent variable-interval chain schedules were employed. Responding on one key led to either a stimulus correlated with reinforcement or a stimulus correlated with time-out. Responding on the other key led to a stimulus which ended either in reinforcement or time-out. The duration of the delay to reinforcement or time-out was varied, the delays for all three stimuli always remaining equal in a given phase. It was found that the longer the delay, the greater the preference for the observing response. In Experiment II a procedure was employed in which birds pecked during a “trial” to produce stimuli correlated with reinforcement or time-out at the end of the trial. The duration of the trial ending in time out was varied while the positive trial duration remained constant. It was found that the longer the duration of the negative trial, the greater the strength of observing responses. The results were interpreted as supporting the hypothesis that the value of a positive stimulus is a function of time spent in stimuli correlated with nonreinforcement.
相似文献9.
The present experiment demonstrated in a simultaneous discrete trial discrimination that the stimulus control of a rat’s leverpress response can be errorlessly transferred across stimulus modalities, i.e., from light to click location and from click to light location. Subsequent to acquisition of the original discrimination, the original and new discriminative stimuli were simultaneously presented for several sessions. Then the new discriminative stimulus was presented 3 sec prior to the onset of the original discriminative stimulus. Within the direction of transfer, e.g., from light to click location, the delay group emitted fewer trial and intertriai errors than the control group. As the new discriminative stimuli acquired control over responding, the response latency distributions were differentially affected. The results suggest that the transfer of control from the original to the new discriminative stimuli is mediated by the temporal aspects of the delay interval. 相似文献
10.
In two experiments, we examined the discrimination of photographs of individual pigeons by pigeons, using go/no-go discrimination procedures. In Experiments 1A and 1B, the pigeons were trained to discriminate 4 photographs of one pigeon from those of a number of pigeons. The subjects learned the discrimination, but their discriminative behavior did not transfer to new photographs taken from novel perspectives. When the pigeons were trained to discriminate between 20 photographs of five pigeons taken from four perspectives as the S+ and 20 photographs of five different pigeons as the S-, the subjects learned the discrimination, and this discriminative behavior partially transferred to new photographs taken from novel perspectives (Experiments 2A-2C). The results suggest that pigeons are able to discriminate among conspecific individuals, using stationary visual cues. This strengthens the assumption in evolutionary theory that animals can discriminate among individuals and encourages further investigation as to how this ability is used in various behaviors of animals. 相似文献
11.
These experiments examined one way in which the allocation of attentional resources can change performance during a visual discrimination task. Pigeons were trained to discriminate visual forms under conditions that produced dimensional contrast. In three experiments, negative training stimuli differed from positive stimuli either along a primary physical dimension alone or along both a primary dimension and an orthogonal dimension. When a negative stimulus differed from positive stimuli along two dimensions, discrimination of that negative stimulus improved. For one type of visual form, discrimination of the positive stimuli declined with orthogonal variation in a negative stimulus, whereas for other visual forms, there was no decline in performance. These results are consistent with a model of dimensional contrast that suggests that differences in the allocation of attentional resources determine discrimination performance. The results also indicate that the organization of stimulus dimensions plays a crucial role in the allocation of attentional resources in these settings. 相似文献
12.
Cognitive performance and development is negatively correlated with fixation duration patterns during infancy, and evidence suggests that long-looking infants may process visual information more slowly than short-looking infants. 3 experiments described here tested the possibility that these differences may be due to differential sensitivity to global and local visual information. Infants were administered discrimination and generalization tasks involving global and local information at varying levels of familiarization time. Results indicated that 4-month-olds process visual information in a global-to-local sequence. Both long- and short-looking infants were sensitive to both types of information, although long lookers required additional familiarization time to match the performance of short lookers. Finally, apparent "generalization" of global information at brief familiarization levels was traced to insensitivity to local stimulus properties. The results do not support the hypothesis that long- and short-looking infants are differentially sensitive to global versus local visual information at 4 months of age. 相似文献
13.
The present experiments examined transfer of training from visual to auditory sensory modalities in classical conditioning of the rabbit’s nictitating membrane response. Experiment 1 examined transfer from initial training with a single visual CS to subsequent auditory discrimination training, and Experiment 2 examined transfer from visual discrimination training to auditory discrimination training. The major findings were that (1) initial conditioning of a visual CS facilitated the overall rate of CR acquisition to the auditory CSs separate from the requirements for discrimination learning (Experiments 1 and 2), and (2) initial visual discrimination training facilitated auditory discrimination learning (Experiment 2). Thus, the animals appeared to encode separately both contiguous CS-US relations and CS+ versus CS? relations during initial visual training. The results are discussed with respect to theories of extradimensional transfer. 相似文献
14.
Steven J. Haggbloom 《Learning & behavior》1980,8(3):441-446
The effects of transitions from nonrewarded (N) to rewarded (R) trials (N-R transitions) on discriminative behavior in differential conditioning and subsequent resistance to extinction were investigated in two experiments. In Experiment 1, groups given N-R transitions within S+ were more resistant to discrimination (ran fast in S?) and extinction than were groups given a partial reinforcement (PRF) schedule in S+ devoid of N-R transitions. Experiment 2 indicated that N-R transitions that occur when an N trial in S? is followed by an R trial in S+ are as effective in increasing resistance to discrimination, but not resistance to extinction, as are N-R transitions that occur within S+. The sequential effects obtained here were highly similar to those in conventional PRF and support the view that differential conditioning and PRF are highly interrelated phenomena. The results are discussed in terms of the extension of sequential theory to differential conditioning and the importance of internal reward-produced cues in discrimination learning. 相似文献
15.
We trained 7 pigeons to discriminate visual displays of 16same items from displays of 16different items. The specific stimulus features of the items and the relations among the items could serve as discriminative stimuli.
Unlike in most studies of same-different discrimination behavior, we gave a small number of probe tests during each session
of acquisition to measure the time-course of control by the learning of specific stimulus features and relational cues. Both
the specific stimulus features and relational cues exerted reliable stimulus control, with the specific stimulus features
exerting more control during the final three fourths of same-different learning. These findings replicate research suggesting
that pigeons encode both the specific stimulus features and relational cues, and for the first time document the time-course
of control by each kind of cue. 相似文献
16.
Web网页是网络课程重要的人机界面,其布局和设计直接影响学习者的学习效果.本文从眼动心理学角度,利用眼动实验研究学习者利用网络课程学习的视觉搜索行为,测量学习者在3种常见的网页布局及其导航样式下学习时的眼动数据,探讨网页布局对网络学习的影响.通过记录注视次数、注视持续时间等6项眼动指标,并结合态度测量,试图揭示学习者学习时的眼动心理生理基本特征,以期找出适宜的网页布局形式和导航样式,为网络课程的设计和开发提出有效建议.实验研究表明：（1）T字型布局有利于学习者进行视觉搜索;（2）国字型布局更有利于学习者对知识的认知加工;（3）学习者进行视觉搜索时兴趣区集中在导航区,进行知识学习时兴趣区集中在主体内容区;（4）学习者在国字型布局下能取得更高的正确率. 相似文献
17.
The ability of visual CSs previously paired with flavored substances to substitute for those substances as conditional discriminative cues was examined in two Pavlovian appetitive conditioning experiments using rat subjects. In Experiment 1, a visual stimulus was first paired with the delivery of a sucrose solution. Then the rats were trained in conditional discrimination tasks in which sucrose delivery alone served as a conditional cue signaling whether or not a subsequent tone would be reinforced with food pellets. Subjects rapidly acquired discriminative performance to the tones, especially in a feature-negative condition in which sucrose delivery signaled when the tone would not be reinforced. In a subsequent test in which neither food nor sucrose was delivered, presentation of the visual CS also controlled discriminative performance to subsequently presented tones. Experiment 2 showed the ability of a visual CS to substitute for a flavored substance as a conditional cue to be highly stimulus specific. Experiment 2 also showed that a flavored substance was less effective as a conditional cue when it was made to be expected by preceding it with a previously associated visual signal than when it was made to be surprising by preceding it with a visual stimulus signaling another flavored liquid. These results indicate that CS-evoked representations of events can substitute for those events themselves in the control of previously established conditional discrimination performance. 相似文献
18.
Hooded rats were reared in very restricted environments with angular, curved, or white-field stimulation. The extent of transfer from this exposure was assessed in adulthood by testing subjects for (a) learning ability in form, brightness, and pattern discrimination tasks, and (b) exploration and activity differences in an open field. The angle-reared group performed better than the other two rearing groups in all three discrimination tasks. Moreover, the curved and white-field groups were equivalent. These learning differences did not appear to result from differences in (a) exploration or activity or (b) dependence on kinesthetic cues. The results demonstrated that one type of early visual stimulation produced transfer to discrimination tasks that varied in difficulty and in degree of relevancy to the rearing forms. This effect was related to the results and interpretations from previous form-rearing studies. Three interpretations were proposed for this transfer and for the advantage of angular vs. curved stimulation. 相似文献
19.
We taught 8 pigeons to discriminate 16-icon arrays that differed in their visual variability or “entropy” to see whether the relationship between entropy and discriminative behavior is linear (in which equivalent differences in entropy should produce equivalent changes in behavior) or logarithmic (in which higher entropy values should be less discriminable from one another than lower entropy values). Pigeons received a go/no-go task in which the lower entropy arrays were reinforced for one group and the higher entropy arrays were reinforced for a second group. The superior discrimination of the second group was predicted by a theoretical analysis in which excitatory and inhibitory stimulus generalization gradients fall along a logarithmic, but not a linear scale. Reanalysis of previously published data also yielded results consistent with a logarithmic relationship between entropy and discriminative behavior. 相似文献
20.
In 5 experiments, 4-month-old infants were tested for their ability to recognize degraded visual targets as a function of individual differences in fixation duration. Targets were degraded by removing 10% of the total contour either from vertices (vertex-absent) or from midsegments (vertex-present). Both qualitative and quantitative differences were found in long and short lookers' ability to recognize the degraded forms. Short-looking infants were able to recognize degraded forms in both vertex-absent and vertex-present conditions, but the vertex-absent discrimination was more difficult. Long-looking infants required longer familiarization times before showing evidence of recognition in the vertex-present condition, and were unable to recognize targets in which contour was removed at vertices. The findings are discussed within the framework of the persistence of early visual processing strategies, and reliance of long-looking infants on particular local elements in visual analysis. 相似文献