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 595 records · Page 33Linked to original sources
PubMed1997

Linguistic cues in the acquisition of number words.

Previous research has shown that children go through a stage in which they know that the number words each refer to a distinct numerosity, yet do not know WHICH numerosity each number word picks out (Wynn, 1992). How do children attain this level of knowledge? We explore the possibility that particular properties of how number words are used within sentences inform children of the semantic class to which they belong. An analysis of transcripts of the spontaneous speech of three one- and two-year-old children and their parents (from the CHILDES database; MacWhinney & Snow, 1990) suggests that the relevant cues are available as input in parents' speech to children, and that children generally honour these properties of number words in their own speech. Implications of this proposal for word learning more generally are discussed.

Child Language↗
PubMed2006

Enhanced discrimination between flavor stimuli: roles of salience modulation and inhibition.

Rats were given intermixed preexposure to the compound flavors AX and BX and to the compound CX in a separate block of trials (4 presentations of each compound). In Experiment 1, rats showed less generalization of conditioned aversion from AX to BX than from CX to BX, a perceptual learning effect. Experiment 2 showed that the formation of an excitatory association proceeded more readily between A and B than between C and B, suggesting that intermixed preexposure maintains the effective salience of A and B and does not establish inhibition between them, a process that would require prolonged preexposure. According to this analysis, salience modulation and associative inhibition may contribute to perceptual learning at different stages of preexposure.

Animals↗
PubMed1996

Learning perceptually salient visual parameters using spatiotemporal smoothness constraints.

A model is presented for unsupervised learning of low level vision tasks, such as the extraction of surface depth. A key assumption is that perceptually salient visual parameters (e.g., surface depth) vary smoothly over time. This assumption is used to derive a learning rule that maximizes the long-term variance of each unit's outputs, whilst simultaneously minimizing its short-term variance. The length of the half-life associated with each of these variances is not critical to the success of the algorithm. The learning rule involves a linear combination of anti-Hebbian and Hebbian weight changes, over short and long time scales, respectively. This maximizes the information throughput with respect to low-frequency parameters implicit in the input sequence. The model is used to learn stereo disparity from temporal sequences of random-dot and gray-level stereograms containing synthetically generated subpixel disparities. The presence of temporal discontinuities in disparity does not prevent learning or generalization to previously unseen image sequences. The implications of this class of unsupervised methods for learning in perceptual systems are discussed.

Algorithms↗
PubMed1987

[Formation of a generalized reaction of choice of object according to color in a young chimpanzee].

It has been established that the necessary conditions for rapid formation of experience in chimpanzees are creation of the interspecific functional system experimenter-chimpanzee in which the mechanisms of imitation and refreshment and creation of situational conditional reflex may be equally used. The neurophysiological basis of the latter is the stage activity when each stage is the signal for the following and refreshment for the previous one. In the presence of these factors the possibility of formation of aim generalized reflex appears, that is the basis for creation of optimum conditions for perception and learning the given information.

Animals↗
PubMed1963

GENERALIZATION OF AUDITORY INTENSITY AS A FUNCTION OF SMALL AMOUNTS OF DISCRIMINATION TRAINING.

Rats were trained on a two-valued auditory-intensity discrimination for 5, 2, 1 or 0 days. Then, the bar-press response rate was sampled in the presence of seven added discrimination stimuli (generalization) for seven days. Daily training sessions were 4 hr in length throughout the experiment. Only the five-day group exhibited a marked superiority on the multi-valued discrimination when contrasted with the group having had no prior simple discrimination training.

Discrimination Learning↗
PubMed2006

When similarity and causality compete in category-based property generalization.

Five experiments were performed to investigate the category-based generalization of nonblank properties, properties that were novel but that were attributed to existing category features with causal explanations. Experiments 1-3 tested how such explanations interact with the well-known effects of similarity on such generalizations. The results showed that when the causal explanations were used, standard effects of typicality (Experiment 1), diversity (Experiment 2), or similarity itself (Experiment 3) were almost completely eliminated. Experiments 4 and 5 demonstrated that category-based generalizations exhibit some of the standard properties of causal reasoning; for example, an effect (i.e., a novel category property) is judged to be more prevalent when its cause (i.e., an existing category feature) is also prevalent. These findings suggest that category-based property generalization is often an instance of causal inference.

Animals↗
PubMed2005

Memory-emotional interactions as revealed by fear generalization in animal-fearful individuals.

Discriminative fear learning and fear generalization were examined in animal-fearful individuals and in control participants. Electrical shocks were administered contingent upon discriminative pictures of spiders or snakes, respectively, in a generalization-after-discrimination paradigm. Neither discriminative fear learning nor extinction was affected by the individual fear status of the animal categories. Novel feared stimuli, which resembled discriminative stimuli, were treated as more shock predictive than novel non-feared stimuli during generalization testing. Neither preparedness theory nor selective sensitization theory was capable to account for these observations. The findings are commensurable with the hypothesis that phobic fear interferes with the retrieval of memory traces.

Adolescent↗
PubMedDate not supplied

Stimulus generalization of conditioned eyelid responses produced without cerebellar cortex: implications for plasticity in the cerebellar nuclei.

In Pavlovian eyelid conditioning and adaptation of the vestibulo-ocular reflex, cerebellar cortex lesions fail to completely abolish previously acquired learning, indicating an additional site of plasticity in the deep cerebellar or vestibular nucleus. Three forms of plasticity are known to occur in the deep cerebellar nuclei: formation of new synapses, plasticity at existing synapses, and changes in intrinsic excitability. Only a cell-wide increase in excitability predicts that learning should generalize broadly from a training stimulus to other stimuli capable of supporting learning, whereas the alternatives predict that learning should be relatively specific to the training stimulus. Here we show that deep nucleus plasticity, as assessed by conditioned eyelid responses produced without input from the cerebellar cortex, is relatively specific to the training conditioned stimulus (CS). We trained rabbits to a tone or light CS with periorbital stimulation as the unconditioned stimulus (US), and pharmacologically disconnected the cerebellar cortex during a posttraining generalization test. The short-latency conditioned responses unmasked by this treatment showed strong decrement along the dimension of auditory frequency and did not generalize across stimulus modalities. These results cannot be explained solely by a cell-wide increase in the excitability of deep nucleus neurons, and imply that an input-specific mechanism in the deep cerebellar nucleus operates as well.

Acoustic Stimulation↗
PubMed1998

Dopamine D1-like receptors and reward-related incentive learning.

There now is general agreement that dopaminergic neurons projecting from ventral mesencephalic nuclei to forebrain targets play a critical role in reward-related incentive learning. Many recent experiments evaluate the role of dopamine (DA) receptor subtypes in various paradigms involving this type of learning. The first part of this paper reviews evidence from these studies that use antagonists or agonists relatively specific for D1- or D2-like receptors in operant paradigms with food, brain stimulation, self-administered stimulant or conditioned rewards or place conditioning. The focus is on studies that directly compare agents acting at the two DA receptor families, especially those studies where the agents produce differential actions. Results support the conclusion that D1-like receptors play a more critical role in reward-related learning than D2-like receptors. D1-like receptors initiate a cascade of intracellular events including cyclic adenosine monophosphate (cAMP) formation and activation of cAMP-dependent protein kinase (PKA). The final section of this paper reviews evidence from a wide range of neuroscience experiments that implicates the cAMP/PKA pathway in learning in general and in reward-related incentive learning in particular. We conclude that the molecular mechanism underlying DA-mediated incentive learning may involve DA release in association with reward, stimulation of D1-like receptors, activation of the cAMP/PKA cascade and additional intracellular events leading to modification of cortico-striatal glutamatergic synapses activated by stimuli encountered in close temporal contiguity with reward. Thus, when reward-related incentive learning takes place, it may be the action of DA acting at D1-like receptors that leads to plastic changes in the striatum that form the substrate of that learning.

Animals↗
PubMed2000

WWW-based continuing medical education: how do general practitioners use it?

WWW-based Continuing Medical Education (CME) is assumed to have the potential to make up for shortcomings in traditional lifelong learning of General Practitioners (GPs). This is obvious for CME systems with accreditation and control of the individual GP's CME activities but seems less clear for non-controlled CME systems like in several European countries, e.g. Germany. This paper reports results from the evaluation of a German CME website by 59 GPs (internet experience of 20 months on average) during a 4-months period. GPs mainly learned at home after work, with 46% of the GPs visiting the website at least once per month. Self-study and information seeking accounted for 58% of the activities, while communication and interaction were used infrequently. 77% of the GPs judged less but detailed information on selected topics more important than being able to access many but broad contents. GPs mostly prefer established means of learning and communication. It is concluded that the GPs' self-directed individual learning mainly needs high-quality information and well-structured collections of existing relevant WWW resources. Communication, virtual community building and sophisticated interactivity are of little importance at present. WWW-based CME complements existing CME activities, especially regarding individual information seeking on focused problems.

Computer Literacy↗
PubMed2005

The rules versus similarity distinction.

The distinction between rules and similarity is central to our understanding of much of cognitive psychology. Two aspects of existing research have motivated the present work. First, in different cognitive psychology areas we typically see different conceptions of rules and similarity; for example, rules in language appear to be of a different kind compared to rules in categorization. Second, rules processes are typically modeled as separate from similarity ones; for example, in a learning experiment, rules and similarity influences would be described on the basis of separate models. In the present article, I assume that the rules versus similarity distinction can be understood in the same way in learning, reasoning, categorization, and language, and that a unified model for rules and similarity is appropriate. A rules process is considered to be a similarity one where only a single or a small subset of an object's properties are involved. Hence, rules and overall similarity operations are extremes in a single continuum of similarity operations. It is argued that this viewpoint allows adequate coverage of theory and empirical findings in learning, reasoning, categorization, and language, and also a reassessment of the objectives in research on rules versus similarity.

Animals↗
PubMed2005

Implementation of formal learning objectives during a physical medicine and rehabilitation sports medicine rotation.

OBJECTIVE: To develop and implement formal learning objectives during a physical medicine and rehabilitation sports medicine rotation and characterize resident experiences with the objectives over a 16-mo period. DESIGN: Prospective, including learning objective development, implementation, and postrotation survey. RESULTS: A total of 69 learning objectives were developed by physical medicine and rehabilitation staff physician consensus, including 39 core objectives. Eighteen residents completed 4-wk sports medicine rotations from January 2003 through April 2004. Residents completed an average of 31 total objectives (45%; range, 3-52), of which 24 (62%; range, 3-35) were core. Residents completed the highest percentage of knee (60%), shoulder (57%), and ankle-foot (57%) objectives and reported that objectives related to these areas were most effective to facilitate learning. In general, residents reported that objective content was good and that the objectives delineated important concepts to learn during the rotation. Seventeen of 18 residents indicated that the objectives should be permanently implemented into the sports rotation and that similar objectives should be developed for other rotations. Based on our experience and the recommendations of residents, the average resident should be able to complete approximately 30 objectives during a typical 4-wk rotation. CONCLUSIONS: Successful implementation of specific, consensus-derived learning objectives is possible within the context of a busy clinical practice. Our initial physician staff and resident experience with the objectives suggests that this model may be useful as a supplementary educational tool in physical medicine and rehabilitation residency programs.

Clinical Competence↗
PubMed2002

A new approach to the formation of equivalence classes in pigeons.

Four pigeons were given simultaneous discrimination training with visual patterns arbitrarily divided into two sets, with the stimuli in one set designated A1, B1, C1, and D1 and those in the other set designated A2, B2, C2, and D2. In sequentially introduced training phases, the pigeons were exposed to a series of reversals to establish AB and then CD equivalences. In subsequent testing sessions, a subset of stimuli from one set served as positive stimuli and those from the other set as negative stimuli on training trials, and transfer of the reinforced relation to other members of the sets was tested with nonreinforced probe trials. The pigeons were trained further on AC and BD equivalences and then were tested for the emergence of untrained AD and BC equivalences. Two of the 4 pigeons exhibited the emergence of one of these untrained equivalences, evidence for the emergence of transitive relations. This finding suggests that the pigeons established three-member functional equivalence classes by incorporating separately trained multiple equivalence relations. Repeated reversal training and probe testing enabled us to explore the formation and expansion of functional equivalence classes in pigeons.

Animals↗
PubMed1993

An evaluation of four student placements in psychiatric nursing.

A sample of senior baccalaureate students enrolled in a psychiatric nursing course was tested before and after four alternative clinical placements to measure student satisfaction. While overall satisfaction with clinical placements was relatively high for this sample and not significantly different among groups, differences were noted when satisfaction was examined for different aspects of clinical learning. In general, traditional inpatient placement settings for psychiatric nursing may be deficient in providing students with substantive learning about substance abuse and rehabilitation models. Both substance abuse based settings and combining a range of settings through which students rotate appear deficient in providing adequate learning about mental illness. Perhaps most important was the improvement in Group 3's preference scores, suggesting the importance to students of the clinical nurse specialist as a role model.

Adult↗
PubMed2006

Evidence that pigeons represent both time and number on a logarithmic scale.

Pigeons were presented with trials that always began with presentation of a houselight that lasted for 1-16s. Red and green side keys were presented immediately after the houselight went off. A peck on the red key was reinforced if the houselight duration was 8s or shorter, and a peck on the green key was reinforced if the houselight duration was 9s or longer. Plots of asymptotic performance as a function of houselight duration showed bow-shaped curves with higher accuracy at the ends of the scale than in the middle. Training to bisect a scale containing houselight durations of 2-32s yielded a performance curve that superimposed on the 1-16s curve. Both curves showed two important asymmetries around the midpoint: pigeons were more accurate at 9 and 10s than at 7 and 8s but were more accurate at 1-4s than at 13-16s. These findings closely resembled those found in a similar study of number scale bisection [Roberts, W.A., 2005. How do pigeons represent numbers? Studies of number scale bisection. Behav. Process. 69, 33-43]. Theoretical predictions from associative and confusion models showed a good match to the obtained data if it was assumed that time and number scales were logarithmic and that generalization or confusion curves were constant but not if it was assumed that scales were linear and that generalization or confusion curves were scalar.

Animals↗