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 271 records · Page 15Linked to original sources

Association of epilepsy with different groups of microcephaly.

Sixty-six participants (33 males, 33 females) with microcephaly (MC), age range from 2 to 19 years old, were evaluated. MC was classified pathogenetically into isolated MC (IMC) and multiple MC (MMC) and classified etiologically into primary MC (PMC) and secondary MC (SMC). Both IMC and MMC were further classified. Overall prevalence of epilepsy was 40.9%. Furthermore, there was a significantly higher prevalence of epilepsy in males. Main seizure type was generalized tonic-clonic seizures. Generally, learning disability (LD) was diagnosed in 93.9% and profound LD was evident in 43.9% of participants. There was an inverse correlation between severity of epilepsy and IQ but a positive correlation between severity of epilepsy and degree of LD. Differences in the success rate between monotherapy and polytherapy or response to antiepileptic drugs were not observed. Results suggest that epilepsy may be associated with the lower cognitive ability of the participants with microcephaly. The pathogenetic classification proposed is of value in delineating the prevalence of epilepsy and LD in the different varieties of MC as compared with the etiological classification.

Adolescent↗

Teaching paediatric dentistry by multimedia: a three-year report.

Clinical cases can now be simulated utilising multimedia and used to teach case management to dental students. The modules developed should provide intellectual stimulation, user-interaction and immediate feedback, in addition to being intuitively navigated and user-helpful. Five paediatric dental case modules (early childhood caries, anterior trauma, anterior coronal fragment, anterior crossbite and dentigerous cyst) were created, installed in a multimedia presentation tool, PathFinder (from Westmead Hospital Dental Clinical School, New South Wales, Australia), and used to teach three classes of fourth year dental students at The University of Melbourne. Questionnaires, focus groups and a review were conducted by an external educational expert. Students responded anonymously to general learning questions and case specific questions using a five-point Likert scale (strongly agree to strongly disagree). Student responses indicated they were very enthusiastic about learning via multimedia, although a few students disliked this educational approach. Focus groups and external review indicated that the modules were navigated readily and were suitably interactive.

Case Management↗

Attention within auditory word perception: insights from the phonemic restoration illusion.

Phonemic restoration is a powerful auditory illusion that arises when a phoneme is removed from a word and replaced with noise, resulting in a percept that sounds like the intact word with a spurious bit of noise. It is hypothesized that the configurational properties of the word impair attention to the individual phonemes and thereby induce perceptual restoration of the missing phoneme. If so, this impairment might be unlearned if listeners can process individual phonemes within a word selectively. Subjects received training with the potentially restorable stimuli (972 trials with feedback); in addition, the presence or absence of an attentional cue, contained in a visual prime preceding each trial, was varied between groups of subjects. Cuing the identity and location of the critical phoneme of each test word allowed subjects to attend to the critical phoneme, thereby inhibiting the illusion, but only when the prime also identified the test word itself. When the prime provided only the identity or location of the critical phoneme, or only the identity of the word, subjects performed identically to those subjects for whom the prime contained no information at all about the test word. Furthermore, training did not produce any generalized learning about the types of stimuli used. A limited interactive model of auditory word perception is discussed in which attention operates through the lexical level.

Attention↗

Practice effects in backward masking.

In two experiments we demonstrate that much larger practice effects occur in a backward masking paradigm where patterned masks are used than in similar visual processing paradigms, such as lateral masking and whole report. In additional experiments we examine four possible explanations for the large practice effects: increased familiarity with the paradigm in general, learning about the targets, learning about the masks, and enhanced sensory processing. Because of failure to observe similar practice effects in related paradigms not involving backward masking and because of the sustained nature of the improvement, we reject the first explanation as a source of practice effect. Experiment 3 allowed us to reject target learning as a source of improvement as well; target sets were switched at the end of training, but no decrement in performance was observed. In Experiment 4, mask sets were switched at the end of training, revealing a significant decrement in performance. Learning about the specific masks, then, does contribute to the observed improvement. However, it is responsible for only about one third of the overall improvement in performance. The final experiment provides evidence that the residual improvement is due to enhanced sensory processing. In that experiment, training on backward masking led to a lowered threshold in a two-flash paradigm but not to a significant change in whole-report performance.

Attention↗

The potential of virtual reality in social skills training for people with autistic spectrum disorders.

BACKGROUND: People with autism experience profound and pervasive difficulties in the social domain. Attempts to teach social behaviours tend to adopt either a behavioural or a 'theory of mind' (ToM) approach. The beneficial aspects and limitations of both paradigms are summarized before an examination of how virtual reality technology may offer a way to combine the strengths from both approaches. METHODS: This is not an exhaustive review of the literature; rather, the papers are chosen as representative of the current understanding within each broad topic. Web of Science ISI, EMBASE and PsycInfo were searched for relevant articles. RESULTS: Behavioural and ToM approaches to social skills training achieve some success in improving specific skills or understanding. However, the failure to generalize learned behaviours to novel environments, and the unwieldy nature of some behavioural methodologies, means that there is a need for a training package that is easy to administer and successful in promoting learning across contexts. CONCLUSIONS: Virtual reality technology may be an ideal tool for allowing participants to practise behaviours in role-play situations, whilst also providing a safe environment for rule learning and repetition of tasks. Role-play within virtual environments could promote the mental simulation of social events, potentially allowing a greater insight into minds. Practice of behaviours, both within and across contexts, could also encourage a more flexible approach to social problem solving. Virtual environments offer a new and exciting perspective on social skills training for people with autistic spectrum disorders.

Autistic Disorder↗

Prediction of beta-turns in proteins using neural networks.

The use of neural networks to improve empirical secondary structure prediction is explored with regard to the identification of the position and conformational class of beta-turns, a four-residue chain reversal. Recently an algorithm was developed for beta-turn predictions based on the empirical approach of Chou and Fasman using different parameters for three classes (I, II and non-specific) of beta-turns. In this paper, using the same data, an alternative approach to derive an empirical prediction method is used based on neural networks which is a general learning algorithm extensively used in artificial intelligence. Thus the results of the two approaches can be compared. The most severe test of prediction accuracy is the percentage of turn predictions that are correct and the neural network gives an overall improvement from 20.6% to 26.0%. The proportion of correctly predicted residues is 71%, compared to a chance level of about 58%. Thus neural networks provide a method of obtaining more accurate predictions from empirical data than a simpler method of deriving propensities.

Algorithms↗

The effect of fitting procedure on hearing protector attenuation.

Realistically evaluating the effectiveness of hearing protectors continues to be a major problem in hearing conservation. The purpose of this study was to examine a laboratory-based fitting procedure (User Fit) that was designed to yield hearing protector attenuation values similar to that derived from field studies. Ten subjects who were naive to hearing protectors were used in a repeated measures design that measured real ear attenuation at threshold for two types of plugs. Each subject was tested in two fitting conditions that varied based on the type and degree of assistance given to the subjects by the experimenter. The results showed significant differences in attenuation based on the fitting procedure used, with the User Fit best approximating field data. In addition, a generalized learning effect was noted. The results suggest that any experience with earplugs leads to subsequent improvement in attenuation despite the type of earplug used. Further testing is planned with greater numbers of subjects and additional types of hearing protectors.

Adult↗

Generalized regression neural networks in time-varying environment.

The current state of knowledge regarding nonstationary processes is significantly poorer then in the case of stationary signals. In many applications, signals are treated as stationary only because in this way it is easier to analyze them; in fact, they are nonstationary. Nonstationary processes are undoubtedly more difficult to analyze and their diversity makes application of universal tools impossible. In this paper we propose a new class of generalized regression neural networks working in nonstationary environment. The generalized regession neural networks (GRNN) studied in this paper are able to follow changes of the best model, i.e., time-varying regression functions. The novelty is summarized as follows: 1) We present adaptive GRNN tracking time-varying regression functions. 2) We prove convergence of the GRNN based on general learning theorems presented in Section IV. 3) We design in detail special GRNN based on the Parzen and orthogonal series kernels. In each case we precise conditions ensuring convergence of the GRNN to the best models described by regression function. 4) We investigate speed of convergence of the GRNN and compare performance of specific structures based on the Parzen kernel and orthogonal series kernel. 5) We study various nonstationarities (multiplicative, additive, "scale change," "movable argument") and design in each case the GRNN based on the Parzen kernel and orthogonal series kernel.

Environment↗

Patient education needs as reported by congestive heart failure patients and their nurses.

Patients with congestive heart failure (CHF) need considerable education to enable them to provide effective self-care for their chronic illness. No information has been published about the learning needs of this population. The purpose of this study was to examine hospitalized CHF patients and their nurses' perceptions regarding the importance and realism of typical patient education content. An instrument to assess learning needs was developed and piloted for use in this study. Thirty hospitalized patients and 26 nurses were surveyed. Both nurses and patients rated all information as important to learn and realistic to learn during the patients' hospitalizations. Patients and nurses agreed that medication information was the most important to learn. Generally, patients rated information as more important than nurses rated the same information areas. Suggested nursing interventions and future research endeavours are addressed.

Adult↗

Ordinal judgments of numerical symbols by macaques (Macaca mulatta).

Two rhesus monkeys (Macaca mulatta) learned that the arabic numerals 0 through 9 represented corresponding quantities of food pellets. By manipulating a joystick, the monkeys were able to make a selection of paired numerals presented on a computer screen. Although the monkeys received a corresponding number of pellets even if the lesser of the two numerals was selected, they learned generally to choose the numeral of greatest value even when pellet delivery was made arrhythmic. In subsequent tests, they chose the numerals of greater value when presented in novel combinations or in random arrays of up to five numerals. Thus, the monkeys made ordinal judgments of numerical symbols in accordance with their absolute or relative values.

Animals↗

Family organization as an ecology of ideas: an alternative to the reification of family systems.

The argument of this paper is that current structuralist and quasi-organismic models of family organization are descriptions masquerading as explanations. They correctly assert, but do not account for, the fact that the behavior of each member of a family is related to that of every other member. An adequate account must begin by assuming that people behave according to how they define the situations in which they are actors, and that such definitions of the situation are generalizations learned through repeated interaction with others. Family organization is regarded within this framework as the outcome of an evolutionary process by which some ideas are encouraged or confirmed and others suffer a kind of death or extinction, so that the ideas of each family member lead him or her to behave in ways that confirm or support the ideas of every other family member. That is what is meant by the slogan "family organization as an ecology of ideas." This view of family organization requires a demystified account of resistance in psychotherapy, a bare outline of which is provided in the previous section. The overall conception of the psychotherapeutic process presented here is closest to that of the Palo Alto Brief Therapy Project, though I offer as a conjecture that the effective operations of all the psychotherapies can be explained within this framework.

Communication↗

Responsiveness of delinquents and non-delinquents to social reinforcement.

A series of six experiments, involving 198 subjects, examined the hypothesis that delinquents are less responsive than non-delinquents to social reinforcement and punishment. The hypothesis received support (a) using two different experimental techniques, one in which the subjects' judgements of autokinetic movement were modified and one using the Taffel (1955) verbal conditioning paradigm; (b) with the female adult administering the reinforcement and with a peer; (c) when the contingent social cues were rewarding (Good or Fine) and when they were punishing ('No'). The hypothesis was not supported when the verbal reinforcement was varied. Control studies using no reinforcement and money reinforcement indicated that the social reinforcement did indeed have a specific reinforcement effect and that delinquents did not show a general learning deficiency.

Adolescent↗

Variability of lip and jaw movements in the speech of children and adults.

One purpose of the present study was to examine displacement variability of lower lip and jaw movements to determine whether sounds that are generally learned earlier and should, therefore, have been practiced more (e. g., stops and nasals) would be less variable than sounds that tend to develop later (e. g., fricatives). It was also of interest to determine whether individual articulators such as the lower lip and the jaw show any differences in displacement variability, given that lower lip gestures may need to be more precise than jaw movements. Repetitions of several labial-initial, CVC stimuli embedded in short phrases produced by three groups of children (5-, 8-, and 11-year-olds) and a group of adults were examined to determine the variability of articulatory gestures. No evidence was found to suggest that fricatives were more variable than stops or nasals for any of the groups. For the children but not the adults, lower lip gestures tended to be more variable than jaw movements.

Adult↗

An assessment of small simulators used to teach basic airway management.

This study assessed small simulators sold for teaching basic airway management. The assessment used criteria based on guidelines produced by the Australian Resuscitation Council and our experience teaching health professional trainees. Criteria included how well the simulators demonstrated manoeuvres to open the airway, mouth-to-mouth and mask-to-mouth expired air resuscitation and artificial ventilation using a bag and mask. Simulators with permanently open airways (as is the case with some intubation manikins) were not tested. Each simulator was also assessed for realism in relation to look and feel, hygiene and sturdiness of construction. Clinical staff and medical students who teach basic airway management undertook a standardized assessment of nine simulators. There were significant differences between simulators that could impact on learning. Generally, models with hard surfaces tended to be less realistic in both look and feel compared to those with flexible "skin". Realism of lung inflation and its relationship to airway opening manoeuvres varied greatly between simulators. The Little Anne small simulator functioned most realistically in our tests.

Cardiopulmonary Resuscitation↗

Plasticity-associated gene Krox24/Zif268 is required for long-lasting behavioral effects of cocaine.

The extracellular signal-regulated kinases (ERKs) 1/2 pathway is stimulated by drugs of abuse in striatal neurons through coincident activation of dopamine D1 and glutamate NMDA receptors and is critical for long-lasting behavioral effects of these drugs. Although regulation of transcription is a major target of ERK, the precise mechanisms by which it contributes to behavioral alterations is not known. We examined the role of Zif268, an immediate-early gene induced by drugs of abuse under the control of ERK, in behavioral responses to cocaine using knock-in mutant mice in which Zif268 was replaced by LacZ. No biochemical or behavioral differences between mutant and wild-type mice were observed in basal conditions or in acute responses to cocaine injection. In contrast, locomotor sensitization to single or repeated cocaine injections was dramatically diminished in both heterozygous and homozygous Zif268 mutant mice. Conditioned place preference in response to cocaine was prevented in Zif268-deficient mice. This effect was not attributable to a general learning deficit because the mutant mice displayed normal conditioned place preference when food was used as reward. Our results provide direct genetic evidence for the requirement of Zif268 for long-lasting association of environmental context with specific behavioral responses after short exposures to cocaine. They also underline the common molecular machinery involved in long-lasting drug-induced behavioral alterations and the formation of other types of memory.

Analysis of Variance↗

Statistical methods for assessing measurement error (reliability) in variables relevant to sports medicine.

Minimal measurement error (reliability) during the collection of interval- and ratio-type data is critically important to sports medicine research. The main components of measurement error are systematic bias (e.g. general learning or fatigue effects on the tests) and random error due to biological or mechanical variation. Both error components should be meaningfully quantified for the sports physician to relate the described error to judgements regarding 'analytical goals' (the requirements of the measurement tool for effective practical use) rather than the statistical significance of any reliability indicators. Methods based on correlation coefficients and regression provide an indication of 'relative reliability'. Since these methods are highly influenced by the range of measured values, researchers should be cautious in: (i) concluding acceptable relative reliability even if a correlation is above 0.9; (ii) extrapolating the results of a test-retest correlation to a new sample of individuals involved in an experiment; and (iii) comparing test-retest correlations between different reliability studies. Methods used to describe 'absolute reliability' include the standard error of measurements (SEM), coefficient of variation (CV) and limits of agreement (LOA). These statistics are more appropriate for comparing reliability between different measurement tools in different studies. They can be used in multiple retest studies from ANOVA procedures, help predict the magnitude of a 'real' change in individual athletes and be employed to estimate statistical power for a repeated-measures experiment. These methods vary considerably in the way they are calculated and their use also assumes the presence (CV) or absence (SEM) of heteroscedasticity. Most methods of calculating SEM and CV represent approximately 68% of the error that is actually present in the repeated measurements for the 'average' individual in the sample. LOA represent the test-retest differences for 95% of a population. The associated Bland-Altman plot shows the measurement error schematically and helps to identify the presence of heteroscedasticity. If there is evidence of heteroscedasticity or non-normality, one should logarithmically transform the data and quote the bias and random error as ratios. This allows simple comparisons of reliability across different measurement tools. It is recommended that sports clinicians and researchers should cite and interpret a number of statistical methods for assessing reliability. We encourage the inclusion of the LOA method, especially the exploration of heteroscedasticity that is inherent in this analysis. We also stress the importance of relating the results of any reliability statistic to 'analytical goals' in sports medicine.

Bias↗

Can response force be shaped by reinforcement?

Frick in 1986, writing in this journal, suggested that experiments purporting to demonstrate the shaping of response force by reinforcement lacked critical controls. He argued instead that such procedures create a mental schema concerning the response topography which influences force indirectly. Although Frick's methodological criticisms are well taken, there is additional evidence suggesting that response force can be strengthened by reinforcement and that such learning generalizes across behaviors.

Animals↗