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Bayesian Brain

Rachel Newby, Jane Alty, Peter Kempster
Mind-brain dualism has dominated historical commentary on dystonia, a dichotomous approach that has left our conceptual grasp of it stubbornly incomplete. This is particularly true of functional dystonia, most diagnostically challenging of all functional movement disorders, in which the question of inherent psychogenicity remains a focus of debate. Phenomenological signs considered in isolation lack the specificity to distinguish organic and nonorganic forms, and dystonia's variability has frustrated attempts to develop objective laboratory-supported standards...
October 18, 2016: Movement Disorders: Official Journal of the Movement Disorder Society
Marco Reisert, Elias Kellner, Bibek Dhital, Jürgen Hennig, Valerij G Kiselev
Diffusion-sensitized magnetic resonance imaging probes the cellular structure of the human brain, but the primary microstructural information gets lost in averaging over higher-level, mesoscopic tissue organization such as different orientations of neuronal fibers. While such averaging is inevitable due to the limited imaging resolution, we propose a method for disentangling the microscopic cell properties from the effects of mesoscopic structure. We further avoid the classical fitting paradigm and use supervised machine learning in terms of a Bayesian estimator to estimate the microstructural properties...
October 13, 2016: NeuroImage
Marloes A M Janssen, Max Hinne, Ronald J Janssen, Marcel A van Gerven, Stefan C Steens, Bozena Góraj, Peter P Koopmans, Roy P C Kessels
Despite long-term successful treatment with cART, impairments in cognitive functioning are still being reported in HIV-infected patients. Since changes in cognitive function may be preceded by subtle changes in brain function, neuroimaging techniques, such as resting-state functional magnetic resonance imaging (rs-fMRI) have become useful tools in assessing HIV-associated abnormalities in the brain. The purpose of the current study was to examine the extent to which HIV infection in virologically suppressed patients is associated with disruptions in subcortical regions of the brain in comparison to a matched HIV-negative control group...
October 15, 2016: Brain Imaging and Behavior
Xia Wu, Qing Li, Xinyu Yu, Kewei Chen, Adam S Fleisher, Xiaojuan Guo, Jiacai Zhang, Eric M Reiman, Li Yao, Rui Li
The triple network model, consisting of the central executive network (CEN), salience network (SN) and default mode network (DMN), has been recently employed to understand dysfunction in core networks across various disorders. Here we used the triple network model to investigate the large-scale brain networks in cognitively normal apolipoprotein e4 (APOE4) carriers who are at risk of Alzheimer's disease (AD). To explore the functional connectivity for each of the three networks and the effective connectivity among them, we evaluated 17 cognitively normal individuals with a family history of AD and at least one copy of the APOE4 allele and compared the findings to those of 12 individuals who did not carry the APOE4 gene or have a family history of AD, using independent component analysis (ICA) and Bayesian network (BN) approach...
2016: Frontiers in Aging Neuroscience
Andrew Abboud, Qi Mi, Ava Puccio, David Okonkwo, Marius Buliga, Gregory Constantine, Yoram Vodovotz
Inflammation induced by traumatic brain injury (TBI) is a complex mediator of morbidity and mortality. We have previously demonstrated the utility of both data-driven and mechanistic models in settings of traumatic injury. We hypothesized that differential dynamic inflammation programs characterize TBI survivors vs. non-survivors, and sought to leverage computational modeling to derive novel insights into this life/death bifurcation. Thirteen inflammatory cytokines and chemokines were determined using Luminex™ in serial cerebrospinal fluid (CSF) samples from 31 TBI patients over 5 days...
2016: Frontiers in Pharmacology
Mustapha Bouhrara, Richard G Spencer
A number of central nervous system (CNS) diseases exhibit changes in myelin content and magnetic resonance longitudinal, T1, and transverse, T2, relaxation times, which therefore represent important biomarkers of CNS pathology. Among the methods applied for measurement of myelin water fraction (MWF) and relaxation times, the multicomponent driven equilibrium single pulse observation of T1 and T2 (mcDESPOT) approach is of particular interest. mcDESPOT permits whole brain mapping of multicomponent T1 and T2, with data acquisition accomplished within a clinically realistic acquisition time...
October 8, 2016: NeuroImage
Nienke A V Derks, Harm J Krugers, Casper C Hoogenraad, Marian Joëls, R Angela Sarabdjitsingh
INTRODUCTION: Early life stress (ELS) increases the risk for developing psychopathology in adulthood. When these effects occur is largely unknown. We here studied at which time during development ELS affects hippocampal synaptic plasticity, from early life to adulthood, in a rodent ELS model. Moreover, we investigated whether the sensitivity of synaptic plasticity to the stress-hormone corticosterone is altered by exposure to ELS. MATERIALS & METHODS: Male and female Wistar rats were exposed to maternal deprivation (MD) for 24h on postnatal day (P)3 or left undisturbed with their mother (control)...
2016: PloS One
Raymond van Ee, Sander Van de Cruys, Luc J M Schlangen, Björn N S Vlaskamp
A daily rhythm that is not in synchrony with the environmental light-dark cycle (as in jetlag and shift work) is known to affect mood and health through an as yet unresolved neural mechanism. Here, we combine Bayesian probabilistic 'cue-conflict' theory with known physiology of the biological clock of the brain, entailing the insight that, for a functional pacemaker, it is sufficient to have two interacting units (reflecting environmental and internal time-of-day cues), without the need for an extra homuncular directing unit...
October 5, 2016: Trends in Neurosciences
Antonio Arjona Valladares, Jaime Gómez González, Carlos M Gómez
The present study tries to analyze the neural basis of the so-called "Inter-trial Validity-Invalidity Effects" by means of Event-Related Potentials. The N1, P2, P3a and P3b components were examined. The aim is to show the sequential effects on Event-Related Potentials by analyzing the effect of previous trial condition (n-1) in the processing of current trial target (n). Event-Related Potentials results indicate that the N1 and P2 components show higher negativity in valid trials preceded by invalid trials with respect to valid trials preceded by valid trials, elicited by the so-called "Processing Negativity"...
October 3, 2016: Neuroscience Research
B O Mainsah, L M Collins, C S Throckmorton
OBJECTIVE: The P300 speller is a popular brain-computer interface (BCI) system that has been investigated as a potential communication alternative for individuals with severe neuromuscular limitations. To achieve acceptable accuracy levels for communication, the system requires repeated data measurements in a given signal condition to enhance the signal-to-noise ratio of elicited brain responses. These elicited brain responses, which are used as control signals, are embedded in noisy electroencephalography (EEG) data...
October 5, 2016: Journal of Neural Engineering
Lawrence R Frank, Vitaly L Galinsky
A new data analysis method that addresses a general problem of detecting spatio-temporal variations in multivariate data is presented. The method utilizes two recent and complimentary general approaches to data analysis, information field theory (IFT) and entropy spectrum pathways (ESP). Both methods reformulate and incorporate Bayesian theory, thus use prior information to uncover underlying structure of the unknown signal. Unification of ESP and IFT creates an approach that is non-Gaussian and non-linear by construction and is found to produce unique spatio-temporal modes of signal behavior that can be ranked according to their significance, from which space-time trajectories of parameter variations can be constructed and quantified...
September 30, 2016: Journal of Physics. A, Mathematical and Theoretical
Eric Jouvent, Edouard Duchesnay, Foued Hadj-Selem, François De Guio, Jean-François Mangin, Dominique Hervé, Marco Duering, Stefan Ropele, Reinhold Schmidt, Martin Dichgans, Hugues Chabriat
OBJECTIVE: To obtain simple models predicting disease evolution at 3 years for a given patient with cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL). METHODS: Based on data obtained in a prospective study of 236 patients, we built and validated models predicting, at the individual level, 3-year changes in Mini-Mental State Examination (MMSE), Mattis Dementia Rating Scale (MDRS), Trail Making Test version B (TMTB), and modified Rankin Scale (mRS)...
September 30, 2016: Neurology
Brian L Day, Timothy Muller, Joanna Offord, Irene Di Giulio
KEY POINTS: When standing, the gain of the body-movement response to a sinusoidally moving visual scene has been shown to get smaller with faster stimuli, possibly through changes in the apportioning of visual flow to self-motion or environment motion. We investigated whether visual-flow speed similarly influences the postural response to a discrete, unidirectional rotation of the visual scene in the frontal plane. Contrary to expectation, the evoked postural response consisted of two sequential components with opposite relationships to visual motion speed...
October 1, 2016: Journal of Physiology
Keita Hirai, Hidetoshi Ishii, Takayuki Shimoshikiryo, Tatsuki Shimomura, Daiki Tsuji, Kazuyuki Inoue, Toshihiko Kadoiri, Kunihiko Itoh
BACKGROUND: Augmented renal clearance (ARC) has frequently been observed in critically ill patients. The risk factors for ARC in patients, including those in the general ward, and their influences on vancomycin (VCM) treatment remain unclear. The aims of this study were to investigate the risk factors for ARC and to evaluate the influence of ARC on the pharmacokinetic parameters of VCM. METHODS: This study included a total of 292 patients with VCM treatment who had normal serum creatinine concentrations...
September 23, 2016: Therapeutic Drug Monitoring
Chuyang Ye, Jerry L Prince
Diffusion magnetic resonance imaging (dMRI) provides information about the microstructure of white matter in the human brain. From dMRI, streamlining tractography is often used to reconstruct computational representations of white matter tracts from which differences in structural connectivity can be explored. In the fiber tracking process, anatomical information can help reduce tracking errors caused by crossing fibers and image noise. In this paper, we propose a Bayesian method for estimating fiber orientations (FOs) guided by anatomical tract information using diffusion tensor imaging (DTI), which is a standard clinical and research dMRI protocol...
September 19, 2016: Computerized Medical Imaging and Graphics: the Official Journal of the Computerized Medical Imaging Society
Sarah J Alger, Bret R Larget, Lauren V Riters
Complex vocal signals, such as birdsong, contain acoustic elements that differ in both order and duration. These elements may convey socially relevant meaning, both independently and through their interactions, yet statistical methods that combine order and duration data to extract meaning have not, to our knowledge, been fully developed. Here we design novel semi-Markov methods, Bayesian estimation and classification trees to extract order and duration information from behavioural sequences and apply these methods to songs produced by male European starlings, Sturnus vulgaris, in two social contexts in which the function of song differs: a spring (breeding) and autumn (nonbreeding) context...
June 2016: Animal Behaviour
Damon A Lowes, Helen F Galley, Alessandro P S Moura, Nigel R Webster
Much is still unknown about the mechanisms of effects of even brief anaesthesia on the brain and previous studies have simply compared differential expression profiles with and without anaesthesia. We hypothesised that network analysis, in addition to the traditional differential gene expression and ontology analysis, would enable identification of the effects of anaesthesia on interactions between genes. Rats (n=10 per group) were randomised to anaesthesia with isoflurane in oxygen or oxygen only for 15min, and 6h later brains were removed...
September 19, 2016: Behavioural Brain Research
Facundo Costa, Hadj Batatia, Thomas Oberlin, Carlos D'Giano, Jean-Yves Tourneret
This paper deals with EEG source localization. The aim is to perform spatially coherent focal localization and recover temporal EEG waveforms, which can be useful in certain clinical applications. A new hierarchical Bayesian model is proposed with a multivariate Bernoulli Laplacian structured sparsity prior for brain activity. This distribution approximates a mixed ℓ20 pseudo norm regularization in a Bayesian framework. A partially collapsed Gibbs sampler is proposed to draw samples asymptotically distributed according to the posterior of the proposed Bayesian model...
September 15, 2016: NeuroImage
Kristian Sandberg, Jakob Udby Blicher, Simon Hviid Del Pin, Lau Møller Andersen, Geraint Rees, Ryota Kanai
Across a century or more, ambiguous stimuli have been studied scientifically because they provide a method for studying the internal mechanisms of the brain while ensuring an unchanging external stimulus. In recent years, several studies have reported correlations between perceptual dynamics during bistable perception and particular brain characteristics such as the grey matter volume of areas in the superior parietal lobule (SPL) and the relative GABA concentration in the occipital lobe. Here, we attempt to replicate previous results using similar paradigms to those used in the studies first reporting the correlations...
October 2016: Cortex; a Journal Devoted to the Study of the Nervous System and Behavior
Michael P I Becker, Alexander M Nitsch, Johannes Hewig, Wolfgang H R Miltner, Thomas Straube
Several regions of the frontal cortex interact with striatal and amygdala regions to mediate the evaluation of reward-related information and subsequent adjustment of response choices. Recent theories discuss the particular relevance of dorsal anterior cingulate cortex (dACC) for switching behavior; consecutively, ventromedial prefrontal cortex (VMPFC) is involved in mediating exploitative behaviors by tracking reward values unfolding after the behavioral switch. Amygdala, on the other hand, has been implied in coding the valence of stimulus-outcome associations and the ventral striatum (VS) has consistently been shown to code a reward prediction error (RPE)...
September 10, 2016: NeuroImage
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