PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “GENERALIZATION LEARNING”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

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

At least 325 records · Page 18Linked to original sources

Contact between people with learning disability and general practitioners: a cross-sectional case note survey.

BACKGROUND: This paper describes primary care consultation rates in a sample of people with learning disability. The study was carried out as part of a wider survey of primary care for this population group in response to concerns over quality of care and debate between general practitioners (GPs) and the local health authority over the need for additional remuneration for caring for people with learning disability. Estimates of consultation rates in the literature to date are conflicting and we sought to provide local data on the number and type of contacts with the primary care teams to inform this debate. METHOD: A primary care case note review was carried out of 112 people with learning disability aged over 18, identified from an administrative sample of 967 people known to health and social services. Contact rates (with practice nurses or GPs) were calculated and indirectly standardized for age using data from the fourth National Morbidity Survey in General Practice (MSGP4). RESULTS: Standardized consultation ratio in men was 156 (95 per cent confidence interval (CI) 142-172), in women was 111 (95 per cent CI 102-121) and for both sexes was 127 (95 per cent CI 120-135). Average contact rate was 4.6 per person per year. Eighty per cent of contacts were with GPs. Eighteen per cent (95 per cent CI 11-25 per cent) of subjects consulted, on average, more than once every two months. Limited information on underlying cause of learning disability and severity was available. Consultation rates were independent of age and sex, and were not increased in people with Down's syndrome or epilepsy compared with the rest of the sample population. Consultation rates were highest in people living in staffed group homes (p = 0.01). The presence of special arrangements between practices and residential facilities did not appear to increase service contact, but this finding is prone to measurement bias. CONCLUSIONS: Contrary to the findings of previous studies, people with learning disability consult primary care teams more frequently than the general population. However, this should not be taken as supporting calls for additional resources without addressing the effectiveness and appropriateness of health care offered.

Adult↗

Generalization of motor learning based on multiple field exposures and local adaptation.

Previous studies have used transfer of learning over workspace locations as a means to determine whether subjects code information about dynamics in extrinsic or intrinsic coordinates. Transfer has been observed when the torque associated with joint displacement is similar between workspace locations-rather than when the mapping between hand displacement and force is preserved-which is consistent with muscle- or joint-based encoding. In the present study, we address the generality of an intrinsic coding of dynamics and examine how generalization occurs when the pattern of torques varies over the workspace. In two initial experiments, we examined transfer of learning when the direction of a force field was fixed relative to an external frame of reference. While there were no beneficial effects of transfer after training at a single location (experiments 1 and 2), excellent performance was observed at the center of the workspace after training at two lateral locations (experiment 2). Experiment 3 and associated simulations assessed the characteristics of this generalization. In these studies, we examined the patterns of transfer observed after adaptation to force fields that were composed of two subfields that acted in opposite directions. The experimental and simulated data are consistent with the idea that information about dynamics is encoded in intrinsic coordinates. The nervous system generalizes dynamics learning by interpolating between sets of control signals, each locally adapted to different patterns of torques.

Adaptation, Physiological↗

Generalization in place learning across geometrically different environments is impaired by hippocampal lesions in rats.

A recent study (Tommasi & Thinus-Blanc, 2004) found that when rats trained to search for food hidden in the center of a square-shaped enclosure were tested in the absence of food, they searched precisely in the center of the enclosure. Transfer tests carried out in enclosures differing in shape or size (rectangular-, large square-, and equilateral triangle-shaped) showed that rats searched in the geometric center of the novel environments. In the present work, half of those rats were lesioned bilaterally to the hippocampus and were then re-trained and re-tested in the same task, to be compared to sham rats that received the same retraining/re-test protocol. Results show that lesioned rats, although unimpaired in relearning to localize the center of the square-shaped enclosure, performed considerably worse than sham rats in the transfer tests in the enclosures differing in shape, suggesting a relevant role of the hippocampus in geometry-driven place generalization.

Animals↗

How do general practice registrars learn from their clinical experience? A critical incident study.

OBJECTIVE: This preliminary study of RACGP registrars in the period of subsequent general practice experience examines the types of clinical experiences from which registrars learn, what they learn from the experiences and the process of learning from such experiences. METHOD: A critical incident method was used on a semi structured interview process. Registrars were asked to recall clinical incidents where they had learnt something of importance. Data were sorted and categorised manually. RESULTS: Nine registrars were interviewed before new categories of data ceased to develop. Registrars learnt from the opportunity to follow up patients. An emotional response to the interaction was an important part of the learning process. Learning from such experiences is haphazard and unstructured. Registrars accessed human resources in response to their clinical difficulties rather than text or electronic based information sources. CONCLUSION: Registrars should be aware of their emotional responses to interactions with patients; these emotional responses often indicate important learning opportunities. Clinical interactions and resultant learning could be made less haphazard by structuring consultations with patients with specific problems. These learning opportunities should be augmented by the promotion of follow up of patients.

Australia↗

General practitioners and learning by audit.

The ways in which ;medical audit' can be used in the continuing education of general practitioners are examined, and certain rules for the conduct of such education in small groups of peers are put forward. However, it proved impossible to evaluate the outcome of the educational exercise because those taking part refused to audit twice any single aspect of their daily work.

Education, Medical, Continuing↗

Hippocampal representation in place learning.

The generality of the place-learning impairment associated with hippocampal system damage was challenged using methods of training that permitted subjects to form an individual association between the place of escape and a particular navigational route in an open-field water maze. Both normal rats and rats with fornix lesions (FX rats) acquired this task rapidly, although FX rats were slightly slower in achieving minimum escape latencies. In postcriterion testing, FX rats occasionally made near misses but, more often, their escape performance was indistinguishable from that of intact rats. Results from a variety of probe tests indicated that FX rats, like normal rats, had based their performance on a representation of multiple distal cues but their representation, unlike that of normal rats, was inflexible in that it could not be used to guide performance when the cues or starting position were altered. These results parallel those from other studies of hippocampal function in animals and humans: The learning deficit consequent to hippocampal system damage (1) is not specific to a particular category of learning materials, but is dependent on the representational demands of the task; (2) is observed when task demands encourage a representation based on relations among multiple cues, but not when the task encourages adaptation to an individual (or compound) stimulus; (3) spares acquisition of fundamental procedures needed to perform the task; and (4) impairs the flexible use of learned information in tests other than repetition of the learning experience.

Animals↗

Recency effects as a window to generalization: separating decisional and perceptual sequential effects in category learning.

Accounts of learning and generalization typically focus on factors related to lasting changes in representation (i.e., long-term memory). The authors present evidence that shorter term effects also play a critical role in determining performance and that these recency effects can be subdivided into perceptual and decisional components. Experimental results based on a probabilistic category structure show that the previous stimulus exerts a contrastive effect on the current percept (perceptual recency) and that responses are biased toward or away from the previous feedback, depending on the similarity between successive stimuli (decisional recency). A method for assessing these recency effects is presented that clarifies open questions regarding stimulus generalization and perceptual contrast effects in categorization and in other domains.

Attention↗

General conditions for predictivity in learning theory.

Developing theoretical foundations for learning is a key step towards understanding intelligence. 'Learning from examples' is a paradigm in which systems (natural or artificial) learn a functional relationship from a training set of examples. Within this paradigm, a learning algorithm is a map from the space of training sets to the hypothesis space of possible functional solutions. A central question for the theory is to determine conditions under which a learning algorithm will generalize from its finite training set to novel examples. A milestone in learning theory was a characterization of conditions on the hypothesis space that ensure generalization for the natural class of empirical risk minimization (ERM) learning algorithms that are based on minimizing the error on the training set. Here we provide conditions for generalization in terms of a precise stability property of the learning process: when the training set is perturbed by deleting one example, the learned hypothesis does not change much. This stability property stipulates conditions on the learning map rather than on the hypothesis space, subsumes the classical theory for ERM algorithms, and is applicable to more general algorithms. The surprising connection between stability and predictivity has implications for the foundations of learning theory and for the design of novel algorithms, and provides insights into problems as diverse as language learning and inverse problems in physics and engineering.

Algorithms↗

Optimizing generalized motor program and parameter learning.

Two experiments examined generalized motor program (GMP) and parameter learning. Experiment 1 examined the effects of bandwidth knowledge of results (KR) about relative timing in constant and variable practice. The purpose was to determine if movement stability created by the bandwidth manipulation is associated with increased GMP learning and if bandwidth KR interacts with constant and variable practice. Participants were asked to depress four keys sequentially, using the same relative timing structure. Constant practice had one absolute timing requirement, whereas variable practice had three different absolute timing requirements. The results indicated that GMP learning was enhanced by constant practice (independent of the bandwidth KR condition) and by bandwidth KR, when variable practice was used. The findings suggest practice conditions (bandwidth KR, constant practice) that increase movement stability during practice enhance GMP learning. Parameter learning (during transfer), however, was enhanced by variable practice. Experiment 2 attempted to determine how constant and variable practice conditions could be combined to enhance both GMP and parameter learning. The results indicated that developing a stable GMP early in practice--by providing learners with constant practice early in practice--and refining parameter learning later in practice--by providing them with variable practice late in practice--were effective for both GMP and parameter learning. This suggests a hierarchy in the development of programmed actions with a stable GMP being a requisite for developing an effective and stable parameter rule.

Adult↗

Learning, retention and generalization of a mirror tracing skill in Alzheimer's disease.

The present study examined the ability of 12 patients with probable Alzheimer's disease (AD) and 12 age- and education-matched normal control (NC) subjects to learn and retain the visuomotor skills necessary to efficiently trace a pattern (e.g., a 4- or 6-pointed star) seen only in mirror-reversed view. Those AD (N=6) and NC (N=7) subjects who were able to initially perform the basic mirror tracing task did not differ significantly in initial level of performance, learning over trials, retention of the skill over a 30-min delay interval, and generalization of the skill to a new figure or to the opposite direction of tracing. The AD patients who were unable to initially perform the mirror tracing task were significantly worse than those who could perform the task on several neuropsychological measures sensitive to deficits in problem solving and executive functions, but not on tests of global cognitive decline, memory, language, or visuoperceptual functioning. These results indicate that acquisition and retention of a complex visuomotor skill can proceed normally in the early stages of AD in those individuals who can initially perform the basic task, and that inability to perform the basic task may be related to the frontal lobe dysfunction that is often prominent in the disorder.

Aged↗

WAVELENGTH GENERALIZATION AFTER DISCRIMINATION LEARNING WITH AND WITHOUT ERRORS.

Pigeons were trained to discriminate between 580 mk (S+) and 540 mmicro (S-) by procedures which resulted in either a large amount of responding to S-or in little or no responding to S-. A shift in the peak of a postdiscrimination generalization gradient, away from S-, was obtained only if the discrimination was learned with a large amount of responding to S-.

Animals↗

Differentiation learning and auditory generalization in normal and prefrontal dogs after extensive avoidance training.

The continuation of a study of 24 dogs in the stages of avoidance reacquisition, differentiation training and generalization testing is reported. Subjects had previously received avoidance training with either response contingent CS termination on all trials or on only 50 percent of the training trials, prior to the administration of medial or lateral prefrontal lesions in 16 subjects. The remaining 8 subjects served as nonoperated controls. Following the appropriate surgical treatment, subjects were tested twice for generalization along the tonal frequency dimension of the avoidance CS. Trials to reacquisition criterion were comparable among all dogs, and subjects trained earlier with continuous response contingent CS termination had overlall faster response latencies, except for the medial subject that were slower than subjects trained under the partial schedule. Differentiation performance tended to show more success in the group given the earlier continuous response contingent avoidance training, although data from both training groups were variable. Subjects trained with the partial schedule had more extra- and intertial responses, which are considered as a byproduct of residual fear. Systematic effects from the surgical treatments were not found during differentiation training. Stimulus control by tonal frequency was more pronounced in subjects that had received the partial training schedule, and frequency generalization was disrupted by the lesion effects. The data are considered in light of reinforcement determinates from CS prolongation in the modification of defensive reflex control.

Animals↗

The ideal role of the nurse teacher in the clinical area: a comparison of the perspectives of mental health, learning difficulties and general nurses.

This paper reports findings from a study that explored trained nurses' and student nurses' perceptions of the nurse teachers' ideal role in the clinical area. Findings demonstrate a dichotomy of opinion regarding the ideal role of the nurse teacher in the clinical area that relates to the nursing specialties in which trained nurses work. Trained nurses working in general nursing areas favoured a product-focused, inspectorate supervisory role for nurse teachers. Conversely, trained nurses working in mental health and learning difficulties areas favoured a supportive, supervisory role for the nurse teacher that emphasized the learning process and encouraged reflection. The consequence of the different models used for student nurses' experience of supervision are discussed and the issue of nurse teachers' clinical credibility is explored. It is suggested that trained nurses, nurse teachers and student nurses should be involved in negotiating and constructing the role that nurse teachers play in the clinical area.

Attitude of Health Personnel↗