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Learning Performance (learning + performance)
Selected AbstractsDietary restriction affects lifespan but not cognitive aging in Drosophila melanogasterAGING CELL, Issue 3 2010Joep M.S. Burger Summary Dietary restriction extends lifespan in a wide variety of animals, including Drosophila, but its relationship to functional and cognitive aging is unclear. Here, we study the effects of dietary yeast content on fly performance in an aversive learning task (association between odor and mechanical shock). Learning performance declined at old age, but 50-day-old dietary-restricted flies learned as poorly as equal-aged flies maintained on yeast-rich diet, even though the former lived on average 9 days (14%) longer. Furthermore, at the middle age of 21 days, flies on low-yeast diets showed poorer short-term (5 min) memory than flies on rich diet. In contrast, dietary restriction enhanced 60-min memory of young (5 days old) flies. Thus, while dietary restriction had complex effects on learning performance in young to middle-aged flies, it did not attenuate aging-related decline of aversive learning performance. These results are consistent with the hypothesis that, in Drosophila, dietary restriction reduces mortality and thus leads to lifespan extension, but does not affect the rate with which somatic damage relevant for cognitive performance accumulates with age. [source] Evaluation Metrics in Classification: A Quantification of Distance-BiasCOMPUTATIONAL INTELLIGENCE, Issue 3 2003Ricardo Vilalta This article provides a characterization of bias for evaluation metrics in classification (e.g., Information Gain, Gini, ,2, etc.). Our characterization provides a uniform representation for all traditional evaluation metrics. Such representation leads naturally to a measure for the distance between the bias of two evaluation metrics. We give a practical value to our measure by observing the distance between the bias of two evaluation metrics and its correlation with differences in predictive accuracy when we compare two versions of the same learning algorithm that differ in the evaluation metric only. Experiments on real-world domains show how the expectations on accuracy differences generated by the distance-bias measure correlate with actual differences when the learning algorithm is simple (e.g., search for the best single feature or the best single rule). The correlation, however, weakens with more complex algorithms (e.g., learning decision trees). Our results show how interaction among learning components is a key factor to understand learning performance. [source] Enhancing Knowledge Transfer in Classroom Versus Online Settings: The Interplay Among Instructor, Student, Content, and ContextDECISION SCIENCES JOURNAL OF INNOVATIVE EDUCATION, Issue 1 2009Louise Nemanich ABSTRACT This article integrates management education and organizational learning theories to identify the factors that drive the differences in student outcomes between the online and classroom settings. We draw upon theory on knowledge transfer barriers in organizations to understand the interlinking relationships among presage conditions, deep learning process, and product in the 3P model of student learning. We test our model in the context of undergraduate education and find that confidence in the instructor's expertise, perceived content relevance, and the social richness of the classroom learning environment enhance student enjoyment of the course. Confidence in instructor's expertise and perceived content relevance also contribute to greater understanding of causal relationships among course concepts. Enjoyment is positively associated with learning performance in the classroom, but not online, and student ability is positively associated with learning performance in the online context, but not in the classroom. Our results have implications for course designs in the traditional classroom context and the more innovative online environment. [source] Structural and functional changes in the olfactory pathway of adult Drosophila take place at a critical ageDEVELOPMENTAL NEUROBIOLOGY, Issue 1 2003Jean-Marc Devaud Abstract The olfactory system of several holometabolous insect species undergoes anatomical changes after eclosion of the imago, following those occurring during metamorphosis. In parallel, odor experience and learning performance also evolve with age. Here, we analyze the case of adult Drosophila females. Synaptogenesis in the antennal lobe (AL) starts in late pupa and continues during the first days of adult life, at the same time as the behavioral response to odors matures. Individual olfactory glomeruli (DM6, DM2, and V) display specific growth patterns between days 1 and 12 of adult life. Experience can modify the olfactory pathway both structurally and functionally as shown by adaptation experiments. The modifications associated with this form of nonassociative learning seem to take place at a critical age. Exposure to benzaldehyde at days 2,5 of adult life, but not at 8,11, causes behavioral adaptation as well as structural changes in DM2 and V glomeruli. Altered levels in intracellular cAMP, caused by dunce and rutabaga mutants, do not affect the normal changes in glomerular size, at least at day 6 of development, but they prevent those elicited by experience, establishing a molecular difference between glomerular changes of intrinsic versus environmental origin. Taken together, these data demonstrate an imprinting-like phenomenon in the olfactory pathway of young Drosophila adults, and illustrate its glomerulus-specific dynamics. © 2003 Wiley Periodicals, Inc. J Neurobiol 56: 13,23, 2003 [source] Impaired water maze learning performance without altered dopaminergic function in mice heterozygous for the GDNF mutationEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 7 2001R. Gerlai Abstract Exogenous glial cell line-derived neurotrophic factor (GDNF) exhibits potent survival-promoting effects on dopaminergic neurons of the nigrostriatal pathway that is implicated in Parkinson's disease and also protects neurons in forebrain ischemia of animal models. However, a role for endogenous GDNF in brain function has not been established. Although mice homozygous for a targeted deletion of the GDNF gene have been generated, these mice die within hours of birth because of deficits in kidney morphogenesis, and, thus, the effect of the absence of GDNF on brain function could not be studied. Herein, we sought to determine whether adult mice, heterozygous for a GDNF mutation on two different genetic backgrounds, demonstrate alterations in the nigrostriatal dopaminergic system or in cognitive function. While both neurochemical and behavioural measures suggested that reduction of GDNF gene expression in the mutant mice does not alter the nigrostriatal dopaminergic system, it led to a significant and selective impairment of performance in the spatial version of the Morris water maze. A standard panel of blood chemistry tests and basic pathological analyses did not reveal alterations in the mutants that could account for the observed performance deficit. These results suggest that endogenous GDNF may not be critical for the development and functioning of the nigrostriatal dopaminergic system but it plays an important role in cognitive abilities. [source] Enlarged cholinergic forebrain neurons and improved spatial learning in p75 knockout miceEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 3 2000Ursula Greferath Abstract The p75 low affinity neurotrophin receptor (p75) can induce apoptosis in various neuronal and glial cell types. Because p75 is expressed in the cholinergic neurons of the basal forebrain, p75 knockout mice may be expected to show an increased number of neurons in this region. Previous studies, however, have produced conflicting results, suggesting that genetic background and choice of control mice are critical. To try to clarify the conflicting results from previous reports, we undertook a further study of the basal forebrain in p75 knockout mice, paying particular attention to the use of genetically valid controls. The genetic backgrounds of p75 knockout and control mice used in this study were identical at 95% of loci. There was a small decrease in the number of cholinergic basal forebrain neurons in p75 knockout mice at four months of age compared with controls. This difference was no longer apparent at 15 months due to a reduction in numbers in control mice between the ages of 4 and 15 months. Cholinergic cell size in the basal forebrain was markedly increased in p75 knockout mice compared with controls. Spatial learning performance was consistently better in p75 knockout mice than in controls, and did not show any deterioration with age. The results indicate that p75 exerts a negative influence on the size of cholinergic forebrain neurons, but little effect on neuronal numbers. The markedly better spatial learning suggests that the function, as well as the size, of cholinergic neurons is negatively modulated by p75. [source] Acquiring knowledge with limited experienceEXPERT SYSTEMS, Issue 3 2007Der-Chiang Li Abstract: From computational learning theory, sample size in machine learning problems indeed affects the learning performance. Since only few samples can be obtained in the early stages of a system and fewer exemplars usually lead to a low learning accuracy, this research compares different machine learning methods through their classification accuracies to improve small-data-set learning. Techniques used in this paper include the mega-trend diffusion technique, a backpropagation neural network, a support vector machine, and decision trees to explore the machine learning issue with two real medical data sets concerning cancer. The result of the experiment shows that the mega-trend diffusion technique and backpropagation approaches are effective methods of small-data-set learning. [source] KCa2 channels transiently downregulated during spatial learning and memory in ratsHIPPOCAMPUS, Issue 3 2010Bedel Mpari Abstract Small-conductance calcium-activated potassium channels (KCa2) are essential components involved in the modulation of neuronal excitability, underlying learning and memory. Recent evidence suggests that KCa2 channel activity reduces synaptic transmission in a postsynaptic NMDA receptor-dependent manner and is modulated by long-term potentiation. We used radioactive in situ hybridization and apamin binding to investigate the amount of KCa2 subunit mRNA and KCa2 proteins in brain structures involved in learning and memory at different stages of a radial-arm maze task in naive, pseudoconditioned, and conditioned rats. We observed significant differences in KCa2.2 and KCa2.3, but not KCa2.1 mRNA levels, between conditioned and pseudoconditioned rats. KCa2.2 levels were transiently reduced in the dorsal CA fields of the hippocampus, whereas KCa2.3 mRNA levels were reduced in the dorsal and ventral CA fields of the hippocampus, entorhinal cortex, and basolateral amygdaloid nucleus in conditioned rats, during early stages of learning. Levels of apamin-binding sites displayed a similar pattern to KCa2 mRNA levels during learning. Spatial learning performance was positively correlated with levels of apamin-binding sites and KCa2.3 mRNA in the dorsal CA1 field and negatively correlated in the dorsal CA3 field. These findings suggest that KCa2 channels are transiently downregulated in the early stages of learning and that regulation of KCa2 channel levels is involved in the modification of neuronal substrates underlying new information acquisition. © 2009 Wiley-Liss, Inc. [source] Effect of corticosterone on developing hippocampus: Short-term and long-term outcomesHIPPOCAMPUS, Issue 4 2009Wen-Bin He Abstract Many documents implicate that corticosterone plays a negative role in brain function, especially in learning and memory. However, less evidence confirms its direct actions on hippocampal development. In the work reported here, pro treatment, minimum corticosterone administration in infant mice, and con treatment, corticosterone deprivation by adrenalectomy, were used to examine the effects imposed by corticosterone on the structure and function of developing hippocampus. Our study shows that adrenalectomy induces decrease of plasma corticosterone levels and results in the impairment of learning performance and the degenerative changes not in CA regions of hippocampus but in dentate gyrus. Noteworthily, this damage effect is severer in 5-week-old mice than that in 10-week-old mice. In addition, the short-term effect of minimum corticosterone administration may accelerate the development of dentate gyrus of 10-day-old mice. Moreover, minimum corticosterone administration during infancy contributed to the learning performance and the structural integrity of hippocampal CA regions in different developing stages, while this phenomenon was not observed in dentate gyrus. In conclusion, corticosterone is necessary for the development of dentate gyrus, especially in relatively young individuals, and administration with minimum corticosterone in infancy has a long-term positive influence on the hippocampal structure and function in different developing stages. © 2008 Wiley-Liss, Inc. [source] Differential involvement of the dorsal hippocampus in passive avoidance in C57bl/6J and DBA/2J miceHIPPOCAMPUS, Issue 1 2008Petra J.J. Baarendse Abstract The inferior performance of DBA/2 mice when compared to C57BL/6 mice in hippocampus-dependent behavioral tasks including contextual fear conditioning has been attributed to impaired hippocampal function. However, DBA/2J mice have been reported to perform similarly or even better than C57BL/6J mice in the passive avoidance (PA) task that most likely also depends on hippocampal function. The apparent discrepancy in PA versus fear conditioning performance in these two strains of mice was investigated using an automated PA system. The aim was to determine whether these two mouse strains utilize different strategies involving a different contribution of hippocampal mechanisms to encode PA. C57BL/6J mice exhibited significantly longer retention latencies than DBA/2J mice when tested 24 h after training irrespective of the circadian cycle. Dorsohippocampal NMDA receptor inhibition by local injection of the selective antagonist DL -2-amino-5-phosphonovaleric acid (AP5, 3.2 ,g/mouse) before training resulted in impaired PA retention in C57BL/6J but not in DBA/2J mice. Furthermore, nonreinforced pre-exposure to the PA system before training caused a latent inhibition-like reduction of retention latencies in C57BL/6J, whereas it improved PA retention in DBA/2J mice. These pre-exposure experiments facilitated the discrimination of hippocampal involvement without local pharmacological intervention. The results indicate differences in PA learning between these two strains based on a different NMDA receptor involvement in the dorsal hippocampus in this emotional learning task. We hypothesize that mouse strains can differ in their PA learning performance based on their relative ability to form associations on the basis of unisensory versus multisensory contextual/spatial cues that involve hippocampal processing. © 2007 Wiley-Liss, Inc. [source] Evaluation of two types of online help for application softwareJOURNAL OF COMPUTER ASSISTED LEARNING, Issue 4 2000S. Dutke Abstract, A recent trend in application software design is to extend online help systems in order to support exploratory and self-paced learning. Two different information formats, lists of action steps that have to be taken to achieve a goal (operative help) and explanations about how a function works (function-oriented help), were evaluated to assess their effects on learning performance. In two experiments, adult computer novices (N = 60 and N = 20) learned to use experimental graphics software by task-based exploration. After one half of the tasks, the type of tasks changed so that the acquired action schema could no longer be applied. Results indicated that participants who had access to function-oriented help were coping more successfully with the schema change than participants who received operative help. The relevance to the design of software training and online help systems is discussed. [source] Dietary restriction affects lifespan but not cognitive aging in Drosophila melanogasterAGING CELL, Issue 3 2010Joep M.S. Burger Summary Dietary restriction extends lifespan in a wide variety of animals, including Drosophila, but its relationship to functional and cognitive aging is unclear. Here, we study the effects of dietary yeast content on fly performance in an aversive learning task (association between odor and mechanical shock). Learning performance declined at old age, but 50-day-old dietary-restricted flies learned as poorly as equal-aged flies maintained on yeast-rich diet, even though the former lived on average 9 days (14%) longer. Furthermore, at the middle age of 21 days, flies on low-yeast diets showed poorer short-term (5 min) memory than flies on rich diet. In contrast, dietary restriction enhanced 60-min memory of young (5 days old) flies. Thus, while dietary restriction had complex effects on learning performance in young to middle-aged flies, it did not attenuate aging-related decline of aversive learning performance. These results are consistent with the hypothesis that, in Drosophila, dietary restriction reduces mortality and thus leads to lifespan extension, but does not affect the rate with which somatic damage relevant for cognitive performance accumulates with age. [source] Effect of Episodic and Working Memory Impairments on Semantic and Cognitive Procedural Learning at Alcohol Treatment EntryALCOHOLISM, Issue 2 2007Anne Lise Pitel Background: Chronic alcoholism is known to impair the functioning of episodic and working memory, which may consequently reduce the ability to learn complex novel information. Nevertheless, semantic and cognitive procedural learning have not been properly explored at alcohol treatment entry, despite its potential clinical relevance. The goal of the present study was therefore to determine whether alcoholic patients, immediately after the weaning phase, are cognitively able to acquire complex new knowledge, given their episodic and working memory deficits. Methods: Twenty alcoholic inpatients with episodic memory and working memory deficits at alcohol treatment entry and a control group of 20 healthy subjects underwent a protocol of semantic acquisition and cognitive procedural learning. The semantic learning task consisted of the acquisition of 10 novel concepts, while subjects were administered the Tower of Toronto task to measure cognitive procedural learning. Results: Analyses showed that although alcoholic subjects were able to acquire the category and features of the semantic concepts, albeit slowly, they presented impaired label learning. In the control group, executive functions and episodic memory predicted semantic learning in the first and second halves of the protocol, respectively. In addition to the cognitive processes involved in the learning strategies invoked by controls, alcoholic subjects seem to attempt to compensate for their impaired cognitive functions, invoking capacities of short-term passive storage. Regarding cognitive procedural learning, although the patients eventually achieved the same results as the controls, they failed to automate the procedure. Contrary to the control group, the alcoholic groups' learning performance was predicted by controlled cognitive functions throughout the protocol. Conclusion: At alcohol treatment entry, alcoholic patients with neuropsychological deficits have difficulty acquiring novel semantic and cognitive procedural knowledge. Compared with controls, they seem to use more costly learning strategies, which are nonetheless less efficient. These learning disabilities need to be considered when treatment requiring the acquisition of complex novel information is envisaged. [source] A Normativist Account of Language-Based Learning Disability1,2LEARNING DISABILITIES RESEARCH & PRACTICE, Issue 1 2006J. Bruce Tomblin Research on learning disabilities (LD) depends upon a conceptual framework that specifies what it should explain, what kinds of data are needed, and how these data are to be arranged in order to provide a meaningful explanation. An argument is made that LD are no different in this respect than any other form of human illness. In this article, a theory of LD based on weak normativism drawn from the philosophy of medicine is presented. This theory emphasizes that cultural values (norms) determine which aspects of human experience and function are instances of ill health. Thus, ill health is fundamentally normative. However, the experiences and behaviors themselves arise out of the natural world and therefore can be explained by a culturally neutral natural science. Data from a longitudinal study of specific language impairment are used to show that academic achievement is culturally evaluated, that low achievement is disvalued, and that therefore actions are taken to help the poor achiever. Spoken language abilities in kindergarten are associated with judgments of the adequacy of fourth grade academic achievement and are mediated by reading prior to fourth grade and also via a path that is independent of reading. It is argued that poor academic achievement may be viewed as a disvalued state consistent with an illness, whereas language and reading skills can be viewed as basic causal systems that can explain the child's learning performance. Properties of this causal system are value free, except that they can inherit disvalue by their association with poor achievement. It remains to be determined whether the notion of LD is to be equated with poor achievement and therefore serve as a type of illness or whether it is to be viewed as a particular cause of poor achievement and thus functions as a type of disease associated with poor achievement. The conceptual framework lays out the alternative meanings for LD and the choice between these alternatives will ultimately depend on how it is used in the LD research community. [source] Executive dysfunction can explain word-list learning disability in very mild Alzheimer's disease: The Tajiri ProjectPSYCHIATRY AND CLINICAL NEUROSCIENCES, Issue 1 2004RYUSAKU HASHIMOTO msc Abstract, Elderly people with questionable dementia (i.e. a Clinical Dementia Rating (CDR) of 0.5) have been focused on as representing the borderline zone condition between healthy people and dementia patients. Many of them are known to have pathologic traits of very mild Alzheimer's disease (AD). Although they present mild memory disorder, the underlying mechanism has not been fully investigated. Herein is reported the mechanism of learning disability in very mild AD. Eighty-six CDR 0.5 participants and 101 age- and education-matched healthy controls (CDR 0) were randomly selected from a community in the town of Tajiri, Miyagi Prefecture. The word-recall task of the Alzheimer Disease Assessment Scale,Japanese (i.e. learning and recall of 10 words) was administered. The numbers of words recalled in each trial and those never recalled throughout the trials were compared for the two CDR groups. The serial-position function was depicted for three parts (i.e. primary, middle, and recency). The CDR 0.5 group recalled significantly fewer words than the CDR 0 group. The number of never-recalled words was greater in the CDR 0.5 group. A remarkable difference was found in the middle part of the word list. The number of never-recalled words of the CDR 0.5 group was greater in the middle part. The large number of never-recalled words accounted for the poor learning performance of very mild AD participants. The results suggested that very mild AD participants have difficulty in learning and retaining words in the middle part of the word-list because of a functional decline of the central executive system. [source] Environmental enrichment reverses cognitive and molecular deficits induced by developmental lead exposureANNALS OF NEUROLOGY, Issue 1 2003Tomás R. Guilarte PhD Long-term deficits in cognitive function are the principal effects of lead (Pb2+) exposure in children and can be modeled in experimental animals. Current therapeutic approaches in the treatment of childhood Pb2+ intoxication are not effective in reversing learning deficits once they have occurred. We report that environmental enrichment reverses long-term deficits in spatial learning produced by developmental Pb2+ exposure in rats. Enhanced learning performance of Pb2+ -exposed animals reared in an enriched environment was associated with recovery of deficits in N- methyl- D -aspartate receptor subunit 1 (NR1) mRNA and induction of brain-derived neurotrophic factor (BDNF) mRNA in the hippocampus. The effect of environmental enrichment on NR1 and BDNF gene expression was specific to Pb2+ -exposed animals and was present in the absence of changes in the NR2B subunit of the N- methyl- D -aspartate receptor, GluR1, ,CamKII, or PSD-95 gene expression measured in the same animals. Our findings demonstrate that the learning impairments and NR1 subunit mRNA deficits resulting from developmental Pb2+ exposure are reversible if the animals are provided with an enriched environment even after the exposure has occurred. We propose environmental enrichment as a basis for the treatment of childhood Pb2+ intoxication. [source] The effects of animations on verbal interaction in computer supported collaborative learningJOURNAL OF COMPUTER ASSISTED LEARNING, Issue 5 2008M. Sangin Abstract This paper focuses on the interaction patterns of learners studying in pairs who were provided with multimedia learning material. In a previous article, we reported that learning scores were higher for dyads of an ,animations' condition than for dyads of a ,static pictures' condition. Results also showed that offering a persistent display of one snapshot of each animated sequence hindered collaborative learning. In the present paper, further analyses of verbal interactions within learning dyads were performed in order to have a better understanding of both the beneficial effect of animations and the detrimental effect of the presence of persistent snapshots of critical steps on collaborative learning. Results did not show any differences in terms of verbal categories between the two versions of the instructional material, that is, static versus animated pictures. Pairs who were provided with persistent snapshots of the multimedia sequences produced fewer utterances compared to participants without the snapshots. In addition, the persistent snapshots were detrimental both in terms of providing information about the learning content and in terms of producing utterances solely for the purpose of managing the interaction. In this study, evidence also showed that these two verbal categories were positively related to learning performances. Finally, mediation analyses revealed that the negative effect of persistent snapshots was mediated by the fact that peers of the snapshots condition produced less information providing and interaction management utterances. Results are interpreted using a psycholinguistic framework applied to computer-supported collaborative learning (CSCL) literature and general guidelines are derived for the use of dynamic material and persistency tools in the design of CSCL environments. [source] A reflective learning framework to evaluate CME effects on practice reflectionTHE JOURNAL OF CONTINUING EDUCATION IN THE HEALTH PROFESSIONS, Issue 2 2010Kit H. Leung PhD Researcher Abstract Introduction: The importance of reflective practice is recognized by the adoption of a reflective learning model in continuing medical education (CME), but little is known about how to evaluate reflective learning in CME. Reflective learning seldom is defined in terms of specific cognitive processes or observable performances. Competency-based evaluation rarely is used for evaluating CME effects. To bridge this gap, reflective learning was defined operationally in a reflective learning framework (RLF). The operationalization supports observations, documentation, and evaluation of reflective learning performances in CME, and in clinical practice. In this study, the RLF was refined and validated as physician performance was evaluated in a CME e-learning activity. Methods: Qualitative multiple-case study wherein 473 practicing family physicians commented on research-based synopses after reading and rating them as an on-line CME learning activity. These comments formed 2029 cases from which cognitive tasks were extracted as defined by the RLF with the use of a thematic analysis. Frequencies of cognitive tasks were compared in a cross-case analysis. Results: Four RLF cognitive processes and 12 tasks were supported. Reflective learning was defined as 4 interrelated cognitive processes: Interpretation, Validation, Generalization, and Change, which were specified by 3 observable cognitive tasks, respectively. These 12 tasks and related characteristics were described in an RLF codebook for future use. Discussion: Reflective learning performances of family physicians were evaluated. The RLF and its codebook can be used for integrating reflective learning into CME curricula and for developing competency-based assessment. Future research on potential uses of the RLF should involve participation of CME stakeholders. [source] | |||||||||||||