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PubMed1992

Preserved configural learning and spatial learning impairment in rats with hippocampal damage.

This study was undertaken to compare the effect of hippocampal neurotoxic lesions in rats on two behavioral tasks, one a test of spatial learning, and the other an operant discrimination task that is acquired by forming nonspatial configural associations. Lesions of the hippocampus were made with microinjections of ibotenic acid. After postoperative recovery, rats were trained initially to locate a camouflaged escape platform in a water maze using distal spatial cues. Rats also were trained in the maze apparatus with a visible escape platform under conditions in which spatial information was made irrelevant to performance, i.e., cue learning. In an operant task, the same rats were then trained on a discrimination that included simultaneous feature positive and feature negative components (trial types XA+, A-, XB-, B+). After completion of this nonspatial configural learning task, rats received additional training in the water maze using a new platform location for spatial learning. To the extent that proficient performance in both the maze and operant tasks depends on a common function of the hippocampus, i.e., configural learning, the expectation was that hippocampal lesions would prove equally detrimental to performance in both tasks. Contrary to this expectation, lesioned rats were severely impaired in spatial learning but readily acquired the operant discrimination, even exhibiting some evidence of enhanced performance on this nonspatial configural learning task. Performance of the lesioned rats during cue training in the water maze was also enhanced relative to the control group.(ABSTRACT TRUNCATED AT 250 WORDS)

Analysis of Variance↗
PubMed1995

Enhancement of hippocampally-mediated learning and protein kinase C activity by oxiracetam in learning-impaired DBA/2 mice.

The effects of oxiracetam on hippocampally-mediated learning performance and hippocampal protein kinase C (PKC) were examined in C57BL/6Ibg (C57) and DBA/2Ibg (DBA) mice. C57 and DBA mice were subjected to daily injections of oxiracetam (50 mg/kg i.p.) or vehicle (0.9% saline) for a total of 9 days. C57 and DBA mice were examined on a modified version of the Morris water maze task and the contextual fear conditioning task on the last 5 or 2 days, respectively, of the 9-day treatment schedule. When compared with controls, C57 and DBA oxiracetam-treated mice showed no difference in motor skill capability to perform these complex learning tasks (swim speed or ability to freeze). Hippocampal PKC activity was measured in cytosolic, loosely-bound, and membrane-bound homogenate fractions. Oxiracetam-treated DBA mice demonstrated a significant increase in spatial learning performance as determined by the Morris task. DBA performance was also improved in contextual learning as determined by the fear conditioning task. The increase in spatial learning performance was correlated to an increase in membrane-bound PKC. No substantial improvements in C57 mice were observed on either learning task nor did hippocampal PKC activity change in response to oxiracetam treatment. These data demonstrate that the learning impairment of DBA mice can be reversed by treatment with a nootropic agent and support previous studies suggesting that PKC may be one mechanism of action for oxiracetam.

Animals↗
PubMed1982

The relationship between learning disability, intelligence, and paired-associate learning.

Learning disabled (N = 45) and non-learning disabled (N = 39) third and fourth grade boys and girls were compared in four paired-associate situations. The situations respectively measured learning, memory, exemplar learning, and transfer. Intelligence was measured with the WISC-R. The data were nonnormal in distribution, and the results were thus analyzed parametrically for intelligence and group. What appears to be an interaction occurred. Intelligence facilitated performance for normals on the memory task but had a deleterious effect for the learning disabled Ss. The learning disabled high intelligence group, however, performed significantly better than the other groups on the exemplar and transfer tasks. These findings are discussed in terms of conceptualizations of learning disability and the nature of intervention strategies. In addition, concern is raised for the validity for research with these children where the IQ factor is ignored or covaried and not directly investigated.

Child↗
PubMed1997

Lead-induced changes in NMDA receptor complex binding: correlations with learning accuracy and with sensitivity to learning impairments caused by MK-801 and NMDA administration.

This study sought to further evaluate potential mechanistic relationships between Pb-induced alterations in glutamate neurotransmission and behavioral toxicity. It examined correlations between Pb-induced changes in [3H]MK-801 and [3H]CGP-39653 binding sites in 4 different brain regions (frontal cortex, dentate gyrus, CA1 and striatum) and (1) changes in learning accuracy on a multiple repeated acquisition and performance schedule, and (2) sensitivity to the accuracy-impairing effects of MK-801 and NMDA on this learning baseline. All data were obtained from a single population of rats that had been chronically exposed from weaning to 0, 50 or 250 ppm Pb acetate in drinking water and demonstrated selective learning impairments and altered sensitivity to the effects of MK-801 and NMDA on learning accuracy. Pb exposure decreased MK-801 binding and possibly increased CGP-39653 binding, effects statistically significant in some brain regions, but generally exhibiting similar trends across regions. At 0 ppm, higher levels, particularly of MK-801 binding, were associated with higher accuracy levels in the learning paradigm and with greater decrements in learning accuracy following MK-801 or NMDA administration. These linear correlations were negated and in some cases even reversed by 50 and 250 ppm Pb, an effect that might be attributable to an alteration of NMDA receptor complex subunit composition and thus, ligand binding. Of the 4 brain regions examined, striatal MK-801 binding proved to be the best predictor of learning accuracy levels. These data provide additional support for an involvement of the NMDA receptor complex in Pb-induced learning impairments. The fact that these effects were noted most frequently in striatum also raises the possibility that dopamine-glutamatergic interactions contribute to Pb's effects.

2-Amino-5-phosphonovalerate↗
PubMed2001

Life-long learning cell structures--continuously learning without catastrophic interference.

As an extension of on-line learning, life-long learning challenges a system which is exposed to patterns from a changing environment during its entire lifespan. An autonomous system should not only integrate new knowledge on-line into its memory, but also preserve the knowledge learned by previous interactions. Thus, life-long learning implies the fundamental Stability-Plasticity Dilemma, which addresses the problem of learning new patterns without forgetting old prototype patterns. We propose an extension to the known Cell Structures, growing Radial Basis Function-like networks, that enables them to learn their number of nodes needed to solve a current task and to dynamically adapt the learning rate of each node separately. As shown in several simulations, the resulting Life-long Learning Cell Structures posses the major characteristics needed to cope with the Stability-Plasticity Dilemma.

Algorithms↗
PubMed1995

What we have learned from the study of learning in the leech.

The use of invertebrate preparations has contributed greatly to our understanding of the neural basis of learning. The leech is especially useful for studying behavioral changes and their underlying neuronal mechanisms. Learning in the leech is essentially identical to that found in other animals, both vertebrate and invertebrate. Using anatomical and physiological techniques on leeches as they learn, we have begun to characterize the properties of individual neurons and neuronal networks that play a role in learning. We have been able to show two neuronal mechanisms that have not been previously associated with associative conditioning. The first has to do with the importance of contingency: one stimulus [the conditional stimulus (CS)] becomes associated with a second stimulus [the unconditional stimulus, (US)] in proportion to the ability of the CS to predict the US. We have found that important properties for encoding predictability, such as circuit reconfiguration, may lie in the US pathway. The firing of the serotonergic Retzius cells is taken as the US; consistent CS prediction of a US prevents "dropout" of a critical component of one US pathway. Throughout training, predicted USs continue to elicit a barrage of action potentials in these cells. Recurring unpredicted USs degrade both the learning and the response of the Retzius cell to the US. A second insight is that at least two US pathways contribute to learning, the Retzius cell pathway and the nociceptive (N) cell pathway. This second pathway persists after the elimination of the Retzius cell pathway. The observation of multiple US pathways raises a host of issues concerning CS-US convergence and the functional significance of distinct US pathways, and our results are discussed in terms of implications to current models of learning.

Animals↗
PubMed1998

Perirhinal cortex ablation impairs configural learning and paired-associate learning equally.

Combined damage to the perirhinal and entorhinal cortex has been implicated in the formation of stimulus-stimulus associative memories. We show in this article that relative to three normal controls three cynomolgus monkeys with ablations restricted to the perirhinal cortex were impaired on a visual paired associate learning task in which subjects had to learn which of two visual stimuli were associated with a cue stimulus. The subjects with perirhinal cortex ablations also showed an impairment of a similar magnitude on a visual configural learning task in which they had to learn which of two configurations of visual stimuli were associated with food-reward. The stimuli in both tasks were comprised of alphanumeric characters presented upon a touch-screen. Both groups made fewer errors on the configural learning task than on the paired associate learning task. We suggest that performance on both tasks relies critically on the perirhinal cortex due to the specialization of the perirhinal cortex in processing knowledge about objects. We argue that the specializations of this system and of other memory systems such as the hippocampal-fornix spatial/episodic memory system, are conferred by the specialization of their anatomical connections to other structures. We reject the notion that there are specific memory processes such as the hippocampal based configural associative system that was proposed to be critical for configural associative learning.

Animals↗
PubMed1995

Changes in student learning styles and adaptive learning competencies following a senior preceptorship experience.

The purpose of this pre-post comparison study was to examine the effect of the preceptorship experience on the learning styles (the manner in which individuals process information from the environment), adaptive competencies (the congruences between personal skills and task demands) and environmental press perceptions (the subjects' perceptions of the importance of each adaptive competency to effective functioning in a designated environment) of 37 fourth-year baccalaureate nursing students. Using Kolb's theory of experiential learning as the theoretical framework for the study, it was found that the students' learning styles were inconsistently categorized by two versions of Kolb's learning style inventory. The preceptorship experience was perceived by students to have significantly (P < 0.05) improved the development of their adaptive learning competencies. Students perceived the importance of divergent, accommodative and convergent learning competencies to be lower after the preceptorship experience, with the only significant difference (P < 0.05) being between pre- and post-convergent competencies. The preceptorship experience, however, was found to contribute significantly more (P < 0.001) to the students' development of most adaptive competencies than their weekly clinical experiences. The findings support the notion that a senior preceptorship programme is a valuable and worthwhile learning experience to include in baccalaureate nursing curricula.

Adult↗
PubMed1992

Learning from experience: nurse tutors' and student nurses' perceptions of experiential learning in nurse education: some initial findings.

Experiential learning and experiential learning methods have been widely described in the literature as aids to learning about nursing. This paper describes a descriptive study of nurse tutors' and student nurses' perceptions of experiential learning. Two research methods were used: in-depth semi-structured interviews of 12 nurse tutors and 12 student nurses, followed by a questionnaire survey of a total population of nurse tutors in Wales, U.K. (n = 184) and a 100% stratified sample of student nurses in Wales (n = 325). The questionnaire items were devised out of the interview data. This report offers a description of how the study was conducted and some of the findings. Notably, student nurses tended to perceive experiential learning in terms of learning in the clinical setting whilst tutors referred more to experiential learning as a classroom activity. Other findings are described and discussed.

Attitude↗
PubMed1991

Unaware learning versus preserved learning in pharmacologic amnesia: similarities and differences.

The differences between learning in lorazepam (LOR)--or scopolamine (SCOP)--induced amnesia and learning in unaware drug-free normal subjects were examined. The drugs produced impairment in free recall, but did not affect digit span or word retrieval. In a verbal version, but not a motor version, of the serial reaction time task, the subjects who received SCOP or higher dose LOR showed impairment of sequence-specific learning. Subjects who received placebo had no such impairment. In the stem completion paradigm, higher dose LOR, but not SCOP, impaired performance. In a tachistoscopic word identification task, neither drug interfered with repetition priming. Unaware learning and drug-induced amnesic learning were thus dissociable. These findings disconfirm the hypothesis that unaware learning and drug-induced amnesic learning are analogous.

Adolescent↗
PubMed2000

Problem-based learning the distance learning way: a bridge too far?

Since problem-based learning is classically associated with campus based, small group learning conducted over protracted periods of time, it should not, in theory, be well suited to the distance learning mode of study. Just how do you write distance learning materials which adequately accommodate the problem-based learning process, and which acknowledge the variety of problems that could be identified for study? This paper critically examines one distance learning initiative designed to test whether problem-based learning may be delivered to student benefit at post-registration, undergraduate nurse programme level.

Curriculum↗
PubMed1983

Developing medical student competence in lifelong learning: the contract learning approach.

How contract learning may be used in the introduction to clinical medicine is described, with the goal to develop and enhance self-directed learning skills and attitudes of first- and second-year medical students. Essential tasks associated with successful self-directed learning are cited, and the contract method is described as a means for providing medical students with the opportunity to practice these tasks in the study of gerontology. The procedures followed in the implementation of the contract learning method are described, and its impact on both need and to continue learning about ageing and skills in directing independent learning projects are analysed and discussed. In addition, the implications of early preparation for doctor's lifelong learning are discussed.

Attitude of Health Personnel↗
PubMed1997

Anatomy of motor learning. II. Subcortical structures and learning by trial and error.

We used positron emission tomography to study motor learning by trial and error. Subjects learned sequences of eight finger movements. Tones generated by a computer told the subjects whether any particular move was correct or incorrect. A control condition was used in which the subjects generated moves, but there was no feedback to indicate success or failure, and so on learning occurred. In this condition (free selection) the subjects were required to make a finger movement on each trial and to vary the movements randomly over trials. The subjects had a free choice of which finger to move on any one trial. On this task there was no systematic change in responses over trials and no change in the response times. Two other conditions were included. In one the subjects repetitively moved the same finger on all trials and in a baseline condition the subjects heard the pacing tones and auditory feedback but made no movements. Comparing new learning with the free selection task, there was a small activation in the right prefrontal cortex. This may reflect the fact that in new learning, but not free selection, the subject rehearse past moves and adapt their responses accordingly. The caudate nucleus was strongly activated during new learning. It is suggested that this activity may be related either to mental rehearsal or to reinforcement of the movements as a consequence of the outcomes. The putamen was activated anteriorly on the free selection task and more posteriorly when the subjects repetitively made the same movement. It is suggested that the differences in the location of the peak activation in the striatum may represent the operation of different corticostriatal loops. The cerebellar nuclei (bilaterally) and vermis were more active in the new learning condition than during the performance of the free selection task. There was no difference in the activation of the cerebellum when the free selection task was compared with repetitive performance of the same movement. We tentatively suggest that the basal ganglia may be involved in the specification of movement on the basis of memory of either the movements or the outcomes, but that the cerebellum may be more directly involved in changes in the parameters of movement execution.

Acoustic Stimulation↗
PubMedDate not supplied

Learning disabilities as functions of familial learning problems and developmental problems.

A family history of learning problems as provided on a specially designed questionnaire by maternal report was examined in families of 101 children with learning disabilities and 171 children without disabilities. Diagnoses of learning disabilities followed the U.S. Office of Education definition. Students were selected from the Special School District of St. Louis County and the Pattonville School District. A life history of developmental risk factors in the child subject was also examined in the same two groups. Learning disabilities were found to be strongly familial. In principle, the definition of learning disabilities excluded from the study children with problems attributable to child rearing, emotional, or motivational factors. The report of a family history of learning problems is therefore interpreted as consistent with, although not unequivocally supportive of, genetic factors as determinants. Among developmental factors, only male gender proved to have a significant association with learning disabilities.

Adolescent↗
PubMed1992

A comparative study of the learning style preferences of students with learning disabilities and students who are gifted.

The purpose of this study was to investigate whether significant group, gender, and grade differences existed in the learning style preferences of students with learning disabilities and students who are gifted, using the Learning Style Inventory (LSI) (Dunn, Dunn, & Price, 1987). Subjects consisted of 53 students with learning disabilities and 64 gifted students randomly selected from two large public high schools. They were 10th-, 11th-, and 12th-grade students, aged 15 to 17. A three-way analysis of variance on the LSI raw scores revealed significant group differences in preferences for light, design, and kinesthetic modality, and in motivation, persistence, responsibility, parent motivation, and teacher motivation. Significant gender and grade differences were found in preferences for mobility and learning in the afternoon, respectively. A stepwise discriminant analysis revealed six variables that significantly discriminated between the two groups. Findings imply that incorporating the learning styles of students with learning disabilities and students who are gifted is important for individualizing educational programming.

Adolescent↗
PubMed1988

Intermodal learning in infancy: learning on the basis of two kinds of invariant relations in audible and visible events.

In this research, the development of intermodal perception in infancy was examined by using a new method, the intermodal learning method. 3-month-old infants were given the opportunity to learn a relation between 2 single film and soundtrack pairs through a 2-min familiarization period under 1 of 4 conditions. Films of naturalistic events were accompanied by a soundtrack that was (1) appropriate to the composition of the object and synchronous with its motions, (2) appropriate and nonsynchronous, (3) inappropriate and synchronous, or (4) inappropriate and nonsynchronous. A group of control subjects was familiarized with irrelevant films and soundtracks. Then all subjects were tested in a 2-choice intermodal preference test to determine under which familiarization conditions intermodal learning had occurred. Results indicated that only subjects who had been familiarized with appropriate and synchronous film and soundtrack pairs showed evidence of intermodal learning as compared with the performance of control subjects. Intermodal learning occurred on the basis of 2 kinds of invariant audio-visual relations, temporal synchrony, and temporal microstructure specifying the composition of the object. Intermodal learning did not occur through association on the basis of co-occurrence, nor did it occur when any incongruent audio-visual structure was present. These findings support an invariant-detection view of the development of intermodal perception.

Association Learning↗
PubMed1998

Working to learn and learning to work: placement experience of Project 2000 nursing students in Scotland.

It is evident that the Scottish colleges have designed and provided very different curricular arrangements to support students' learning to practise in placements. Evaluation has demonstrated that some of these arrangements are of fundamental importance in facilitating or constraining the educational experience of students, including opportunities for reflection on experience, students' preparation for placements, the role of tutors in students' placement learning, the preparation of mentors and the utility of instruments for the assessment of students' practice-based learning. In addition to the formal provision in support of students' learning to work, students have developed their own informal strategies in order to meet their (sometimes conflicting) needs to maximize practical learning opportunities, ease entry into the nursing team and achieve favourable assessment of learning. Some of these involve working in order to learn. This paper is based on the work of the National Board-funded Evaluation of Project 2000 in Scotland (1992-96). The remit of the evaluation was to examine the teaching/learning processes of the Project 2000 nursing programmes and the new midwifery programmes, and their relationship to the educational outcomes for individual students, giving particular emphasis to the experience of students.

Clinical Competence↗
PubMed2001

Learning endotracheal intubation in a clinical skills learning center: a quantitative study.

This study aimed to develop statistical models describing the learning of endotracheal intubation (ETI). We collected data from 100 subjects undergoing ETI training with intubatable medical models and manikins (airway trainers). Trainees initially viewed a video about ETI and an instructor demonstrated the technique. Subjects then made up to 17 supervised trials. Each trial was scored as a success or failure; this score was the primary outcome used in analyses. Random effects and population-averaged logit models, and a learning model intended to quantify the relative contributions of failed and successful trials to the learning process, were fitted to the data. The logit models provided evidence of differences in difficulty between different airway trainers and differences in success rate related to previous ETI experience. Trainees became familiar with an airway trainer after multiple trials, as demonstrated by a 50% decrease in the odds of successful ETI when starting on a new trainer. The learning model indicated that a trainee learns about as much from 1 successful ETI as from 12 (95% confidence interval, 2-23) failed trials. The results demonstrate the feasibility of statistical modeling of the learning of ETI and provide insight into the learning process.

Anesthesiology↗