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Results for “Discrimination Learning”

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At least 469 records · Page 26Linked to original sources
PubMed1981

Early postnatal x-irradiation of the hippocampus and discrimination learning in adult rats.

Rats with X-irradiation-produced degranulation of the hippocampal dentate gyrus were trained in the acquisition and reversal of simultaneous visual and tactile discriminations in a T-maze. These experiments employed the same treatment, apparatus, and procedure but varied in task difficulty. In the brightness and roughness discriminations, the irradiated rats were not handicapped in acquiring or reversing discriminations of low or low-moderate task difficulty. However, these rats were handicapped in acquiring and reversing discriminations of moderate and high task difficulty. In a Black/White discrimination, in which the stimuli were restricted to the goal-arm walls, the irradiated rats were handicapped in the acquisition (low task difficulty) and reversal (moderate task difficulty) phases of the task. These results suggest that the irradiated rats were not handicapped when the noticeability of the stimuli was high, irrespective of modality used, but were handicapped when the noticeability of the stimuli was low. In addition, these results are consistent with the hypothesis that rats with hippocampal damage are inattentive due to hyperactivity.

Animals↗
PubMed1997

Temporal specificity in serial feature-positive discrimination learning.

Two experiments examined the temporal specificity of learning in operant serial feature-positive discriminations (feature-->target+/target-). Test performance was better when the target cues were presented at their customary times after the features than when they were presented at earlier or later times. When features trained with one feature-target interval were combined with targets trained with another interval, performance was best when the test interval was the same as the interval associated with the feature, suggesting that the temporal information was coded with the feature cue. Finally, the temporal specificity of the responding controlled by occasion setters was unaffected by feature extinction. Implications for the nature of learning in occasion setting are discussed.

Animals↗
PubMed1997

Rhinal cortex lesions impair simultaneous olfactory discrimination learning in rats.

Previous studies have found that combined lesions of the perirhinal and entorhinal (PRER) cortical areas do not impair, and in fact may facilitate, acquisition of successive olfactory discriminations. The present study sought to determine the effect of PRER lesions on the acquisition of simultaneous olfactory discriminations. Rats (N = 24; 9 PRER-lesioned, 15 sham-operated controls) were trained on a single simultaneous olfactory discrimination; PRER-lesioned animals were dramatically and persistently impaired in acquisition of the discrimination relative to sham-operated subjects. These data are consistent with the view that, in concert with the hippocampus, these cortical regions participate in the encoding of relations among multiple extant stimuli.

Animals↗
PubMed1972

Effects of monochromatic rearing on spectral discrimination learning and the peak shift in chicks.

Chicks were hatched and raised in white or monochromatic sodium (589 nm) light. They were trained on a 590 (+) vs. 580 (-) nm successive discrimination. The combined results of two experiments indicated that rearing illumination did not affect discrimination acquisition. All subjects given generalization tests after discrimination training exhibited peak shifts that were equivalent for the two rearing conditions. The peak shifts exhibited by the monochromatically reared subjects represent maximum responding to stimuli they had not previously seen. This result further confirms the notion that behavioral control by the spectral dimension in birds is organized independently of differential early experience on that dimension.

Animals↗