1,721,009 research outputs found
A machine learning approach for MRI-based classification of individuals with mild cognitive impairment
No full textDiagnosis criteria for Mild Cognitive Impairment (MCI) rely on cognitive symptoms and do not require specific biomarker evidence of pathology. Nevertheless, patients may still have subtle brain changes that are identifiable with neuroimaging. To classify MCI patients vs. healthy age-matched controls, two algorithms—Multilayer Perceptron (MLP) and Support Vector Machine (SVM)—were applied to structural MRI data from the OASIS-1 cohort (https://www.oasis-brains.org/). Despite their comparable performance in some measures, the MLP algorithm was preferable due to superior recall of MCI cases
The “neural shift” of sleep quality and cognitive ageing: A resting-state MEG study of transient neural dynamics
No full textSleep quality changes dramatically from young to old age, but its effects on brain dynamics and cognitive functions are not yet fully specified. We applied Hidden Markov Models (HMMs) to resting-state MEG data from a large cohort (N=564) of population-based adults (aged 18-88), in order to characterize transient neural networks and to relate their temporal dynamics to sleep quality and to cognitive performance. Using multivariate analyses of brain-sleep profiles and of brain-cognition profiles, we found that an age-related “neural shift”, expressed as decreased occurrence of “lower-order” brain networks, coupled with increased occurrence of “higher-order” networks, was associated with both increased sleep dysfunction and decreased fluid intelligence above and beyond age. These results suggest that poor sleep quality, as evident in ageing, may lead to a behavior-related shift in neural dynamics
The “neural shift” of sleep quality and cognitive ageing: A resting-state MEG study of transient neural dynamics
No full textSleep quality changes dramatically from young to old age, but its effects on brain dynamics and cognitive functions are not yet fully specified. We applied Hidden Markov Models (HMMs) to resting-state MEG data from a large cohort (N=564) of population-based adults (aged 18-88), in order to characterize transient neural networks and to relate their temporal dynamics to sleep quality and to cognitive performance. Using multivariate analyses of brain-sleep profiles and of brain-cognition profiles, we found that an age-related “neural shift”, expressed as decreased occurrence of “lower-order” brain networks, coupled with increased occurrence of “higher-order” networks, was associated with both increased sleep dysfunction and decreased fluid intelligence above and beyond age. These results suggest that poor sleep quality, as evident in ageing, may lead to a behavior-related shift in neural dynamics
A machine learning approach for MRI-based classification of individuals with mild cognitive impairment
No full textDiagnosis criteria for Mild Cognitive Impairment (MCI) rely on cognitive symptoms and do not require specific biomarker evidence of pathology. Nevertheless, patients may still have subtle brain changes that are identifiable with neuroimaging. To classify MCI patients vs. healthy age-matched controls, two algorithms—Multilayer Perceptron (MLP) and Support Vector Machine (SVM)—were applied to structural MRI data from the OASIS-1 cohort (https://www.oasis-brains.org/). Despite their comparable performance in some measures, the MLP algorithm was preferable due to superior recall of MCI cases
A machine learning approach for MRI-based classification of individuals with mild cognitive impairment
No full textDiagnosis criteria for Mild Cognitive Impairment (MCI) rely on cognitive symptoms and do not require specific biomarker evidence of pathology. Nevertheless, patients may still have subtle brain changes that are identifiable with neuroimaging. To classify MCI patients vs. healthy age-matched controls, two algorithms—Multilayer Perceptron (MLP) and Support Vector Machine (SVM)—were applied to structural MRI data from the OASIS-1 cohort (https://www.oasis-brains.org/). Despite their comparable performance in some measures, the MLP algorithm was preferable due to superior recall of MCI cases
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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