Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Overlearning”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 181 records · Page 10Linked to original sources
PubMed1980

Sequential auditory and visual discriminations after temporal lobe ablation in monkeys.

Studies in the monkey have shown that cortex outside of the primary projection areas in the superior temporal gyrus and in the inferotemporal region in important for the execution of some auditory and visual descriminations. In this study, six monkeys were trained to perform four auditory and two visual discriminations. Retention tests were given prior to bilateral removal of the anterior part of the lateral surface of the superior temporal gyrus, the inferotemporal region, or both areas together. Superior temporal ablations elicited severe deficits on some auditory discriminations. Inferotemporal ablations caused little or no impairment on visual discriminations. This negative finding is attributed to the sequential rather than spatial mode of presentation of visual stimuli, and to overtraining. A single monkey trained on a spatial visual pattern problem without overtraining was impaired. Another monkey tranied to perform an auditory reverse intensity discrimination exhibited a deficit in ability to perform the problem after removal of auditory cortex within the lateral fissure.

Animals↗
PubMed1980

Scopolamine and KCl injections into the caudate nucleus. Overtraining-induced protection against deficits of learning.

To test the hypothesis that extended training of an instrumental task prevents the performance impairments seen after cholinergic and generalized blockade of caudate-putamen complex (NC) activity in animals with a relatively low degree of training, groups of rats were trained to press a lever under a continuous reinforcement schedule for 5, 15 or 25 sessions; The effects of microinjections of scopolamine and potassium chloride into the CN were then assessed. In agreement with early studies in cats, a significant deficit in performance was produced in the animals with a low or medium degree of training, while no changes in learned behavior were seen in the overtained rats. These results show that: (a) normal neural activity of the CN is essential for performance of instrumental behavior during acquisition and early maintenance stages but not after overtraining, and (b) that after extended training the encoding necessary for performance may be transferred to another neural system outside the CN.

Animals↗
PubMed1990

Delayed response, preoperative overtraining, and prefrontal lesions in the rat.

An earlier study in this laboratory found that preoperative overtraining improved retention of a delayed alternation task after prefrontal lesions in the rat. In this study, however, it was found that preoperative overtraining did not improve performance of the rat in a delayed response task following prefrontal lesions. These results support the hypothesis that preoperative overtraining can improve postoperative performance only when postoperative recovery is ordinarily present, as it is with delayed alternation. but not with delayed response, in the prefrontal rat. This suggests that effects of preoperative overtraining and postoperative recovery may be mediated by similar mechanisms. It further suggests that a shift of function, which seems to account for postoperative recovery, may occur in some parts of the normal adult brain as a result of overtraining.

Animals↗
PubMed1992

A threshold for the protective effect of over-reinforced passive avoidance against scopolamine-induced amnesia.

Acetylcholine-receptor blockers produce amnesia of aversively motivated behaviors. However, when animals are submitted to relatively high intensities of footshock (over-reinforcement), anticholinergic treatment does not induce memory impairments. The aim of this work was to determine whether the antiamnesic effect produced by increasing the magnitude of the negative reinforcer is gradually established or if a threshold should be reached to obtain such an effect. Wistar rats were trained in passive avoidance using 2.5, 2.6, 2.7, 2.8, 2.9 or 3.0 mA; 5 min after training they were given one systemic injection of scopolamine (8 mg/kg). An amnesic state was produced in the groups that were trained with the lower intensities (2.5-2.7 mA); with the three higher intensities near-perfect retention was evident. These results suggest that acetylcholine is critically involved in memory consolidation, and that by increasing the magnitude of the negative reinforcer, a threshold is reached where cholinergic activity of the nervous system is not necessary for the development of the consolidation process.

Animals↗
PubMed1982

Cingulate cortical and anterior thalamic neuronal correlates of the overtraining reversal effect in rabbits.

Multiple-unit activity of the cingulate cortex and the anteroventral (AV) nucleus of the thalamus in rabbits was recorded during reversal training, following differential conditioning of a locomotory (wheel rotation) avoidance response. The CS+ and CS- were pure tones (1 or 8 kHz) and the UCS was a footshock delivered through the grid floor of the wheel. One group of the rabbits received original training to a criterion followed immediately by reversal training. A second group received training to criterion followed by additional training sessions (overtraining), prior to reversal training. The results indicated that the overtraining reversal effect (ORE) occurred. That is, the overtrained subjects acquired the reverse discrimination in significantly fewer sessions than the non-overtrained subjects. The overall (non-discriminative) neuronal reactivity in all cingulate cortical laminae was reduced by overtraining, whereas the overall reactivity of the AV thalamus was enhanced. In addition, the non-overtrained subjects manifested a discriminative neuronal response appropriate to the original task (i.e. a greater response to the CS- than to the CS+ for reversal training), throughout the precriterial sessions of reversal training. This persistent 'original habit effect' occurred only at brief latencies (20-30 msec) after CS onset, and only in the deep cortical laminae (V-VI). The neuronal activity of the superficial laminae (I-IV) in non-overtrained subjects underwent a transition, in parallel with the behavior, from a discriminative response appropriate to the original task to one appropriate to the reversal task. No significant training-related changes were seen at any cortical depth in the overtrained subjects. Presentation of non-contingent footshocks during two sessions of reversal training following criterion re-enhanced the overall reactivity and the brief-latency discriminative neuronal response appropriate to the original task, which had undergone decline during reversal training, in the deep cortical laminae of the non-overtrained subjects. The enhanced overall reactivity and the discriminative activity in the superficial laminae of non-overtrained subjects had not declined during reversal training and were not altered by the non-contingent footshocks. The implications of these data are discussed in regard to the neural causation of the ORE.

Animals↗
PubMed1994

Further investigation of preoperative overtraining, visual cortex lesions and black-white discrimination by the rat.

Preoperative overtraining can improve retention after brain lesions. However, studies of effects of overtraining on relearning of a black-white discrimination after visual cortex lesions in the rat have obtained conflicting results. Another experiment was done on this problem. The postoperative performance of overtrained rats was found to be slightly better than that of non-overtrained rats, but the difference was not significant. Nevertheless, when saving scores were computed, differences were significant. These saving score results seem to demonstrate a preoperative overtraining effect. It is suggested that overtraining before surgery produces a shift of function in the brain, and this shift is related to the development of long-term memory.

Animals↗
PubMed1996

Contribution of egocentric spatial memory to place navigation of rats in the Morris water maze.

Place navigation in the Morris water maze can be directed by memory of the target coordinates relative to remote landmarks (allocentric) or by the memory of the start-goal route (egocentric). When the start and goal positions remain constant and visual cues are eliminated by darkness, memory of the route may become decisive. This assumption was tested in 10 male hooded rats using an infrared television tracking system allowing navigation training in the dark. In Expt. 1, these animals were trained to swim in the dark from the start at the S rim of the pool to the goal position in the center of the NW quadrant of the pool. Mean escape latencies decreased from 47 s initially to 16 s during the 24 daily sessions. Another group of 10 male hooded rats learned the same task in the light. Mean escape latencies decreased from 20 s initially to 5 s during 4 daily sessions. In Expt. 2, possible allocentric location of the target was tested in the same rats by rotating both the start and goal positions by 90 degrees counterclockwise (i.e., to E-SW and later to N-SE). Mean escape latency during 5 days after the first rotation increased to 24 s, but returned back to the asymptotic level of 18 s after the second rotation. The same change of the start and goal position (from S-NW to E-SW) in the light only increased escape latency in the first session. In Expt. 3, both the goal position and route direction were changed to N-SW. Surprisingly, the animals rapidly acquired a new heading angle at the start and mean escape latencies were not significantly changed. It is concluded that overtrained place navigation in darkness can be easily changed to a new direction.

Animals↗
PubMed1986

The immediate and long-term effectiveness of overcorrection in treating self-injurious behavior in a mentally retarded adult.

A brief positive practice overcorrection procedure was used as a method of eliminating head-banging in a profoundly mentally retarded adult. Treatment produced an immediate reduction in head-banging episodes, with near zero occurrence of behavior during the third phase of treatment. One year later data collection was resumed on the subject for an 11-week period. Data from the long-term follow-up revealed that head-banging continued to occur, but mean weekly levels of episodes (M = 5.8) were still well below those recorded during the baseline period (M = 18.8). The overcorrection procedure produced immediate short-term effects and, in this case, was also effective in the long-term. Variables related to the maintenance of response suppression are discussed with respect to this intervention's success.

Adult↗
PubMed1986

A review of treatment research for aggressive and disruptive behavior in the mentally retarded.

This study reviews current treatment research on aggression of mentally retarded persons. Twenty-seven studies meet methodological criteria from an initial pool of 47. All the studies reviewed were empirical and had been published in national and internationally recognized journals. Treatments were behavioral and level of mental retardation and ages of the persons studied varied widely. Age and level of mental retardation proved to be significant factors in predicting treatment outcome. Also, it was found that some types of behaviors were treated more frequently than others, with inappropriate verbal responses being the most common, followed by aggression toward others and noncompliance. The implications of these findings are discussed.

Adolescent↗
PubMed1989

Event-related potentials before and after training: chronometry and lateralization of visual N1 and N2.

Event-related potentials (ERPs) were recorded from normal right-handed males in visual-matching tasks before and after training to a high level of automaticity. The amplitude and latency of the left and right hemispheric N1 and N2 components were analyzed. While changes of N1 "after training" relative to "before training" were statistically non-significant, the N2 component appeared to be a sensitive indicator of the variability in chronometry and lateralization of cerebral processes modified by training. The N2 results suggest that with practice the physiological processes underlying performance in a visual-cognitive task become more efficient, selective and localized.

Adult↗