Discrimination and mediated generalization in probability learning.
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Discrimination Learning↗
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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.
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Efficacy of case method learning in general practice for secondary prevention in patients with coronary artery disease: randomised controlled study.
OBJECTIVE: To study the efficacy of case method learning, for general practitioners, on patients' lipid concentrations in the secondary prevention of coronary artery disease. DESIGN: Prospective controlled trial. SETTING: Södertälje, Stockholm County, Sweden. PARTICIPANTS: 255 consecutive patients with coronary artery disease. INTERVENTION: Guidelines were mailed to all general practitioners (n=54) and presented at a common lecture. General practitioners who were randomised to the intervention group participated in recurrent case method learning dialogues at their primary healthcare centres during a two year period. A locally well known cardiologist served as a facilitator. MAIN OUTCOME MEASURE: Concentration of low density lipoprotein cholesterol at baseline and after two years. Analysis according to intention to treat (intervention and control groups (n=88)) was based on group affiliation at baseline. RESULTS: Low density lipoprotein cholesterol was reduced by 0.5 mmol/l (95% confidence interval 0.2 to 0.8 mmol/l) (9.3% (2.9% to 15.8%)) from baseline in patients in the intervention group and by 0.5 (0.1 to 0.9) mmol/l compared with controls (P<0.05). No change occurred in the control group (0.0 (-0.2 to 0.2) mmol/l). Low density lipoprotein cholesterol decreased by 0.6 (0.4 to 0.8) mmol/l in a group of patients who received specialist care. CONCLUSION: Case method learning resulted in a lowering of low density lipoprotein cholesterol in the primary care patients with coronary artery disease comparable to that achieved at a specialist clinic. Conventional presentation of practice guidelines had no effect.
Cholesterol, LDL↗
Learning and generalization in radial basis function networks.
The two-layer radial basis function network, with fixed centers of the basis functions, is analyzed within a stochastic training paradigm. Various definitions of generalization error are considered, and two such definitions are employed in deriving generic learning curves and generalization properties, both with and without a weight decay term. The generalization error is shown analytically to be related to the evidence and, via the evidence, to the prediction error and free energy. The generalization behavior is explored; the generic learning curve is found to be inversely proportional to the number of training pairs presented. Optimization of training is considered by minimizing the generalization error with respect to the free parameters of the training algorithms. Finally, the effect of the joint activations between hidden-layer units is examined and shown to speed training.
Artificial Intelligence↗
Performance and learning of generalized motor programs: relative (GMP) and absolute (parameter) errors.
The effects of practice (Experiment 1) and parameter variability (Experiment 2) on the learning of generalized motor programs (GMPs) and movement parameterization were investigated. In each experiment, 2 tasks with different relative force-time structures were tested. Participants (N = 32, Experiment 1; N = 40, Experiment 2) attempted to exert a pattern of force that resembled in force and time a waveform that was displayed on a computer monitor. In both experiments, the analysis suggested that the GMP, although refined over practice, was relatively stable (i.e., resistant to decay and interference), even early in practice (after 20 trials). In addition, the results indicated that constant and variable parameter practice did not differentially affect GMP learning but did degrade the learning of the parameter that was not varied. The data provided additional evidence for the dissociation of the GMP and the parameterization processes proposed in GMP theory. Contrary to schema theory, the present data suggest an interdependence between the force and the time parameters: The manipulation of 1 of the parameters has a negative effect on the learning of the other parameter.
Adult↗
Sensory feedback therapy and theoretical knowledge of motor control and learning.
Generally the application of artificial sensory feedback therapy (e.g. EMG biofeedback) in neuromuscular rehabilitation is conceived as a psychophysiological operant conditioning technique. Until now there are almost no attempts to link these methods to modern psychological theories of motor control. In the present article a critical review is given of four theoretical systems concerning motor control: closed-loop theory, open-loop theory, schema-theory, and finally a brief overview is presented of recently developed notions on heterarchical and distributed control. Artificial sensory feedback therapy (e.g. EMG feedback) is described against this theoretical background, with an emphasis on the role of feedback in motor learning and motor control. The implications of these theories for new directions in sensory feedback therapy are discussed.
Biofeedback, Psychology↗
Learning priorities and attitudes towards computer-assisted learning of general medical practitioners, general dental practitioners and dental hygienists.
OBJECTIVES: The objectives of this survey were to assess the attitudes and learning priorities of general medical practitioners (GMPs), general dental practitioners (GDPs), and dental hygienists (DHs) working at Jordan University of Science and Technology (JUST), Irbid, Jordan in relation to post-graduate education, to gather information on their attitudes and skills in using computers and computer-assisted learning (CAL) and to see whether the material in this form is acceptable to participate as a means of teaching. METHODS: Data for this study was gathered via a questionnaire distributed to 63 health professionals including GMPs, general dental practitioners and DHs (mean age 24.79 +/- 2.69 years) working at JUST. RESULTS: Of the 63 participants, 80% of the participants have home computers, 38% have office computers at work and only 25% have both home and office computers. Approximately 53% of the participants had their first CAL experience at home. Seventy-three of the participants indicated that connection to Internet is necessary for their work. Seventy-one of the participants were interested in the possibility of using CAL to further improve and increase their medical knowledge. The most important topic for doctors was 'learning about new techniques which may supersede those in current use', for DHs it was 'improve knowledge or skill in radiology', and for dentists it was 'reinforcement of well established techniques commonly used in dental practice'. CONCLUSIONS: It is necessary for practicing health care professionals to update themselves by taking continuous education courses after graduation more conveniently via CAL methods.
Adult↗
The neuroanatomy of mental retardation in the white rat.
A provisional examination of a set of questions pertaining to the neuroanatomical basis of mental retardation was undertaken by assessing the learning ability of 25 different groups of young rats prepared with various cortical and subcortical lesions. The test battery included a visual discrimination, a nonvisual discrimination, a three-cul maze and three separate detour problems. Seven of the 25 groups were impaired in learning all problems (suggestive of a generalized learning impairment) and therefore were viewed as being mentally retarded. One of these groups suffered diffuse multifocal neocortical damage, while the lesions in the remaining six were located either within the parietal cortex, globus pallidus, ventrolateral thalamus, substantia nigra, median raphe or pontine reticular formation. Based upon a variety of observations, it is proposed that the generalized learning impairment seen in our brain-damaged rats, rather than being reducible to a sensory, motor, arousal-motivational-emotional, attentional, inhibitory or recent memory defect, is the product of a defect in "executive" processes.
Animals↗
Learning and generalization in cascade network architectures.
Incrementally constructed cascade architectures are a promising alternative to networks of predefined size. This paper compares the direct cascade architecture (DCA) proposed in Littmann and Ritter (1992) to the cascade-correlation approach of Fahlman and Lebiere (1990) and to related approaches and discusses the properties on the basis of various benchmark results. One important virtue of DCA is that it allows the cascading of entire subnetworks, even if these admit no error-backpropagation. Exploiting this flexibility and using LLM networks as cascaded elements, we show that the performance of the resulting network cascades can be greatly enhanced compared to the performance of a single network. Our results for the Mackey-Glass time series prediction task indicate that such deeply cascaded network architectures achieve good generalization even on small data sets, when shallow, broad architectures of comparable size suffer from overfitting. We conclude that the DCA approach offers a powerful and flexible alternative to existing schemes such as, e.g., the mixtures of experts approach, for the construction of modular systems from a wide range of subnetwork types.
Generalization, Psychological↗
Evidence-Based Pattern Classification: A Structural Approach to Human Perceptual Learning and Generalization
Models of human pattern classification have been traditionally based on implicit pattern descriptions which involve lists of continuous attribute values or discrete features. Here we propose an alternative approach which makes explicit use of pattern structure in terms of components and their unary (part-specific) and binary (part-relational) properties. Such attributes "evidence" different classes of patterns and allow one to model processes of both perceptual learning and generalization to novel instances. An object in an evidence-based system is represented by a set of rules, where each rule provides a certain amount of class-specific evidence. The accumulated class evidence over all activated rules determines the classification probability. We have examined how well this concept reflects human performance by training observers to classify compound Gabor patterns and then testing them with segmented (grey-level-transformed) versions of the patterns in the original training set. If the observers were to construct rules to define each pattern class in terms of perceived parts and their relations, then it should be expected that classification performance would generalize to these new patterns. Results confirm this hypothesis and the specific feature extraction, learning, and rule generation model used to predict performance. Copyright 1997 Academic Press
Journal Article↗
Further lesion studies on the neuroanatomy of mental retardation in the white rat.
Prompted by recent findings suggesting that the basal ganglia and possibly the limbic midbrain area and brainstem reticular formation may be represented within the general learning system of the rat brain, the current study was undertaken to assess the learning ability of different groups of young rats prepared with bilateral lesions to either the caudatoputamen, nucleus accumbens, ventral pallidum, ventromedial thalamus, habenula, subthalamic nucleus, pedunculopontine tegmental nucleus, dorsal raphe, ventral tegmental area, anterior pretectal nucleus, superior colliculus, inferior colliculus, or red nucleus. The test battery included both appetitively (three distinct climbing detour problems) and aversively (visual discrimination, three cul maze, and an inclined plane discrimination) motivated learning tasks. Only those animals with lesions to the posterodorsal caudatoputamen, ventral tegmental area of Tsai, or superior colliculus were deficient in acquiring all six problems (suggestive of a generalized learning impairment) and therefore were viewed as being mentally retarded. The overall findings pertaining to the general learning system are interpreted within a conceptual framework based upon Spearman's two-factor theory of intelligence. The significance of these data for a brain-injured animal model of mental retardation is also discussed.
Animals↗
Task difficulty and the specificity of perceptual learning.
Practising simple visual tasks leads to a dramatic improvement in performing them. This learning is specific to the stimuli used for training. We show here that the degree of specificity depends on the difficulty of the training conditions. We find that the pattern of specificities maps onto the pattern of receptive field selectivities along the visual pathway. With easy conditions, learning generalizes across orientation and retinal position, matching the spatial generalization of higher visual areas. As task difficulty increases, learning becomes more specific with respect to both orientation and position, matching the fine spatial retinotopy exhibited by lower areas. Consequently, we enjoy the benefits of learning generalization when possible, and of fine grain but specific training when necessary. The dynamics of learning show a corresponding feature. Improvement begins with easy cases (when the subject is allowed long processing times) and only subsequently proceeds to harder cases. This learning cascade implies that easy conditions guide the learning of hard ones. Taken together, the specificity and dynamics suggest that learning proceeds as a countercurrent along the cortical hierarchy. Improvement begins at higher generalizing levels, which, in turn, direct harder-condition learning to the subdomain of their lower-level inputs. As predicted by this reverse hierarchy model, learning can be effective using only difficult trials, but on condition that learning onset has previously been enabled. A single prolonged presentation suffices to initiate learning. We call this single-encounter enabling effect 'eureka'.
Humans↗
Portfolio-based learning and general practice vocational training.
This action research project developed a portfolio-based learning system, based around a 'log dairy,' with the trainers and general practitioner registrars of one training region in the UK. For those that found benefit from the system, the diary became an important way of holding all the events of a training year together; a way of looking back, in order to view the progress made, and looking forward, to view potential learning needs. Such portfolios were not found to be effective formal assessment mechanisms because the threat of assessment influenced the type of material collected. The enthusiasm of trainers was crucial in encouraging use of the model. The action research process was fundamental in stimulating explorations of ideas on reflective learning. There remains some resistance to the idea of reflective writing, and in this context, portfolios may be one educational tool for use by some, but which may not be universally applicable. Their development and implementation requires considerable local support through facilitation.
Family Practice↗
Stimulus generalization and discrimination learning by primates.
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Animals↗
Primary stimulus generalization in discrimination learning as a function of numbers of trials and incidental cue differences.
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Cues↗
Category learning. Learning the general but not the specific.
Amnesia patients have a normal ability to learn categories from examples, even though they fail to learn the examples themselves; computational models of brain function suggest how and why.
Amnesia↗
Recognition-by-parts: a computational approach to human learning and generalization of shapes.
In this paper human pattern recognition is modeled in terms of how human observers learn to describe patterns in terms of their perceived parts, their unary (part) and binary (relational) attributes and the way in which such attribute states "evidence' different classes of shapes. This approach, originally developed in the area of computer vision, is concerned with algorithms which enable the learning of shape descriptions from examples and the classification of new data (generalization) efficiently and accurately. An object in such an "evidence-based' system is represented by a set of rules, where each rule provides a certain amount of evidence for each object class in the database. The accumulated class evidence over all activated rules can then be used to determine the classification probability. We have examined how well this model reflects human perception by training observers to classify compound Gabor patterns and then testing them with versions of such patterns which were segmented (gray-level transformed) versions of the original training set. If the observers were to construct rules to define each pattern class in terms of perceived parts and their relations, then it should be expected that classification performance would generalize to these new patterns from the original set. Results confirm this hypothesis and the specific feature extraction, learning and rule generation model used to predict performance.
Attention↗
Retrograde amnesic and facilitative effects of ether on learning and generalization gradients.
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Amnesia↗
Generalization of learning in three-and-a-half-month-old infants on the basis of amodal relations.
Infants of 3.5 months (N = 124) were given the opportunity to learn to relate two objects and their natural, distinctive sounds during a training phase. The objects and sounds were united by temporal synchrony and amodal audiovisual information specifying object composition. Infants then participated in one of three types of transfer tests (requiring low, moderate, or high degrees of generalization) to measure the extent to which intermodal knowledge generalized to a new task and across events (familiar events; change in color/shape; change in substance, motion, and color/shape). Results indicated that infants tested with the familiar events and with events of a new color/shape showed learning and transfer of knowledge. In contrast, infants tested with events of a new substance, motion, and color/shape showed no generalization of learning. Thus, infants of 3.5 months appear to show a moderate degree of generalization of intermodal knowledge across events. Although this knowledge is not restricted to the events of original learning, it cannot yet be flexibly extended across a variety of contexts.
Auditory Perception↗