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Bayesian Brain

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https://www.readbyqxmd.com/read/28419235/a-bayesian-group-sparse-multi-task-regression-model-for-imaging-genetics
#1
Keelin Greenlaw, Elena Szefer, Jinko Graham, Mary Lesperance, Farouk S Nathoo
Motivation: Recent advances in technology for brain imaging and high-throughput genotyping have motivated studies examining the influence of genetic variation on brain structure. Wang et al. (Bioinformatics, 2012) have developed an approach for the analysis of imaging genomic studies using penalized multi-task regression with regularization based on a novel group l2,1-norm penalty which encourages structured sparsity at both the gene level and SNP level. While incorporating a number of useful features, the proposed method only furnishes a point estimate of the regression coefficients; techniques for conducting statistical inference are not provided...
April 13, 2017: Bioinformatics
https://www.readbyqxmd.com/read/28408150/adaptive-and-maladaptive-neural-compensatory-consequences-of-sensory-deprivation-from-a-phantom-percept-perspective
#2
REVIEW
Anusha Mohan, Sven Vanneste
It is suggested that the brain undergoes plastic changes in order to adapt to changing environmental needs. Sensory deprivation results in decreased input to the brain leading to adaptive or maladaptive changes. Although several theories hypothesize the mechanism of these adaptive and maladaptive changes, the course of action taken by the brain heavily depends on the age of incidence of damage. The growing body of literature on the topic proposes that maladaptive changes in the brain are instrumental in creating phantom percepts, defined as the perception of a sensory experience in the absence of a physical stimulus...
April 10, 2017: Progress in Neurobiology
https://www.readbyqxmd.com/read/28402428/bayesian-mapping-reveals-that-attention-boosts-neural-responses-to-predicted-and-unpredicted-stimuli
#3
Marta I Garrido, Elise G Rowe, Veronika Halász, Jason B Mattingley
Predictive coding posits that the human brain continually monitors the environment for regularities and detects inconsistencies. It is unclear, however, what effect attention has on expectation processes, as there have been relatively few studies and the results of these have yielded contradictory findings. Here, we employed Bayesian model comparison to adjudicate between 2 alternative computational models. The "Opposition" model states that attention boosts neural responses equally to predicted and unpredicted stimuli, whereas the "Interaction" model assumes that attentional boosting of neural signals depends on the level of predictability...
April 10, 2017: Cerebral Cortex
https://www.readbyqxmd.com/read/28399440/altered-effective-brain-connectivity-at-early-response-of-antipsychotics-in-first-episode-schizophrenia-with-auditory-hallucinations
#4
Leilei Zheng, Weibo Liu, Wei He, Shaohua Yu, Guodong Zhong
OBJECTIVE: This study aimed to examine the alterations of cortical connectivity in first-episode schizophrenia (FES) with auditory hallucinations at early response of antipsychotics. METHODS: This was a nonexperimental control of medication study. We measured the cortical activity of 20 medicated patients with FES (medicated group), 19 nonmedicated patients with FES (nonmedicated group), and 22 healthy controls using electroencephalogram during eye-open resting state...
February 20, 2017: Clinical Neurophysiology: Official Journal of the International Federation of Clinical Neurophysiology
https://www.readbyqxmd.com/read/28389385/automatized-set-up-procedure-for-transcranial-magnetic-stimulation-protocols
#5
S Harquel, J Diard, E Raffin, B Passera, G Dall'Igna, C Marendaz, O David, A Chauvin
Transcranial Magnetic Stimulation (TMS) established itself as a powerful technique for probing and treating the human brain. Major technological evolutions, such as neuronavigation and robotized systems, have continuously increased the spatial reliability and reproducibility of TMS, by minimizing the influence of human and experimental factors. However, there is still a lack of efficient set-up procedure, which prevents the automation of TMS protocols. For example, the set-up procedure for defining the stimulation intensity specific to each subject is classically done manually by experienced practitioners, by assessing the motor cortical excitability level over the motor hotspot (HS) of a targeted muscle...
April 4, 2017: NeuroImage
https://www.readbyqxmd.com/read/28386575/comparing-diffuse-optical-tomography-and-functional-magnetic-resonance-imaging-signals-during-a-cognitive-task-pilot-study
#6
Estefania Hernández-Martin, Francisco Marcano, Oscar Casanova, Cristian Modroño, Julio Plata-Bello, Jose Luis González-Mora
Diffuse optical tomography (DOT) measures concentration changes in both oxy- and deoxyhemoglobin providing three-dimensional images of local brain activations. A pilot study, which compares both DOT and functional magnetic resonance imaging (fMRI) volumes through t-maps given by canonical statistical parametric mapping (SPM) processing for both data modalities, is presented. The DOT series were processed using a method that is based on a Bayesian filter application on raw DOT data to remove physiological changes and minimum description length application index to select a number of singular values, which reduce the data dimensionality during image reconstruction and adaptation of DOT volume series to normalized standard space...
January 2017: Neurophotonics
https://www.readbyqxmd.com/read/28385875/correlates-of-perceptual-orientation-biases-in-human-primary-visual-cortex
#7
Matthew L Patten, Damien J Mannion, Colin W G Clifford
Vision can be considered as a process of probabilistic inference. In a Bayesian framework, perceptual estimates from sensory information are combined with prior knowledge, with a stronger influence of the prior when the sensory evidence is less certain. Here, we explored the behavioral and neural consequences of manipulating stimulus certainty in the context of orientation processing. First, we asked participants to judge whether a stimulus was oriented closer to vertical or the clockwise primary oblique (45°) for two stimulus types (spatially-filtered noise textures, sinusoidal gratings) and three manipulations of certainty (orientation bandwidth, contrast, duration)...
April 6, 2017: Journal of Neuroscience: the Official Journal of the Society for Neuroscience
https://www.readbyqxmd.com/read/28382008/a-goal-directed-bayesian-framework-for-categorization
#8
Francesco Rigoli, Giovanni Pezzulo, Raymond Dolan, Karl Friston
Categorization is a fundamental ability for efficient behavioral control. It allows organisms to remember the correct responses to categorical cues and not for every stimulus encountered (hence eluding computational cost or complexity), and to generalize appropriate responses to novel stimuli dependant on category assignment. Assuming the brain performs Bayesian inference, based on a generative model of the external world and future goals, we propose a computational model of categorization in which important properties emerge...
2017: Frontiers in Psychology
https://www.readbyqxmd.com/read/28377631/a-bayesian-perspective-on-accumulation-in-the-magnitude-system
#9
Benoît Martin, Martin Wiener, Virginie van Wassenhove
Several theoretical and empirical work posit the existence of a common magnitude system in the brain. Such a proposal implies that manipulating stimuli in one magnitude dimension (e.g. duration in time) should interfere with the subjective estimation of another magnitude dimension (e.g. size in space). Here, we asked whether a generalized Bayesian magnitude estimation system would sample sensory evidence using a common, amodal prior. Two psychophysical experiments separately tested participants on their perception of duration, surface, and numerosity when the non-target magnitude dimensions and the rate of sensory evidence accumulation were manipulated...
April 4, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28360419/algorithms-for-survival-a-comparative-perspective-on-emotions
#10
REVIEW
Dominik R Bach, Peter Dayan
The nature and neural implementation of emotions is the subject of vigorous debate. Here, we use Bayesian decision theory to address key complexities in this field and conceptualize emotions in terms of their relationship to survival-relevant behavioural choices. Decision theory indicates which behaviours are optimal in a given situation; however, the calculations required are radically intractable. We therefore conjecture that the brain uses a range of pre-programmed algorithms that provide approximate solutions...
May 2017: Nature Reviews. Neuroscience
https://www.readbyqxmd.com/read/28344546/choosing-muse-validation-of-a-low-cost-portable-eeg-system-for-erp-research
#11
Olave E Krigolson, Chad C Williams, Angela Norton, Cameron D Hassall, Francisco L Colino
In recent years there has been an increase in the number of portable low-cost electroencephalographic (EEG) systems available to researchers. However, to date the validation of the use of low-cost EEG systems has focused on continuous recording of EEG data and/or the replication of large system EEG setups reliant on event-markers to afford examination of event-related brain potentials (ERP). Here, we demonstrate that it is possible to conduct ERP research without being reliant on event markers using a portable MUSE EEG system and a single computer...
2017: Frontiers in Neuroscience
https://www.readbyqxmd.com/read/28343976/prophylactic-cranial-irradiation-versus-observation-in-patients-with-extensive-disease-small-cell-lung-cancer-a-multicentre-randomised-open-label-phase-3-trial
#12
Toshiaki Takahashi, Takeharu Yamanaka, Takashi Seto, Hideyuki Harada, Hiroshi Nokihara, Hideo Saka, Makoto Nishio, Hiroyasu Kaneda, Koichi Takayama, Osamu Ishimoto, Koji Takeda, Hiroshige Yoshioka, Motoko Tachihara, Hiroshi Sakai, Koichi Goto, Nobuyuki Yamamoto
BACKGROUND: Results from a previous phase 3 study suggested that prophylactic cranial irradiation reduces the incidence of symptomatic brain metastases and prolongs overall survival compared with no prophylactic cranial irradiation in patients with extensive-disease small-cell lung cancer. However, because of the absence of brain imaging before enrolment and variations in chemotherapeutic regimens and irradiation doses, concerns have been raised about these findings. We did a phase 3 trial to reassess the efficacy of prophylactic cranial irradiation in the treatment of extensive-disease small-cell lung cancer...
March 23, 2017: Lancet Oncology
https://www.readbyqxmd.com/read/28337122/cerebrospinal-fluid-cortisol-mediates-brain-derived-neurotrophic-factor-relationships-to-mortality-after-severe-tbi-a-prospective-cohort-study
#13
Miranda J Munoz, Raj G Kumar, Byung-Mo Oh, Yvette P Conley, Zhensheng Wang, Michelle D Failla, Amy K Wagner
Distinct regulatory signaling mechanisms exist between cortisol and brain derived neurotrophic factor (BDNF) that may influence secondary injury cascades associated with traumatic brain injury (TBI) and predict outcome. We investigated concurrent CSF BDNF and cortisol relationships in 117 patients sampled days 0-6 after severe TBI while accounting for BDNF genetics and age. We also determined associations between CSF BDNF and cortisol with 6-month mortality. BDNF variants, rs6265 and rs7124442, were used to create a gene risk score (GRS) in reference to previously published hypothesized risk for mortality in "younger patients" (<48 years) and hypothesized BDNF production/secretion capacity with these variants...
2017: Frontiers in Molecular Neuroscience
https://www.readbyqxmd.com/read/28334230/guided-bayesian-imputation-to-adjust-for-confounding-when-combining-heterogeneous-data-sources-in-comparative-effectiveness-research
#14
Joseph Antonelli, Corwin Zigler, Francesca Dominici
In comparative effectiveness research, we are often interested in the estimation of an average causal effect from large observational data (the main study). Often this data does not measure all the necessary confounders. In many occasions, an extensive set of additional covariates is measured for a smaller and non-representative population (the validation study). In this setting, standard approaches for missing data imputation might not be adequate due to the large number of missing covariates in the main data relative to the smaller sample size of the validation data...
March 3, 2017: Biostatistics
https://www.readbyqxmd.com/read/28333493/bayesian-approaches-to-autism-towards-volatility-action-and-behavior
#15
Colin J Palmer, Rebecca P Lawson, Jakob Hohwy
Autism spectrum disorder currently lacks an explanation that bridges cognitive, computational, and neural domains. In the past 5 years, progress has been sought in this area by drawing on Bayesian probability theory to describe both social and nonsocial aspects of autism in terms of systematic differences in the processing of sensory information in the brain. The present article begins by synthesizing the existing literature in this regard, including an introduction to the topic for unfamiliar readers. The key proposal is that autism is characterized by a greater weighting of sensory information in updating probabilistic representations of the environment...
May 2017: Psychological Bulletin
https://www.readbyqxmd.com/read/28327290/bayesian-brains-without-probabilities
#16
REVIEW
Adam N Sanborn, Nick Chater
Bayesian explanations have swept through cognitive science over the past two decades, from intuitive physics and causal learning, to perception, motor control and language. Yet people flounder with even the simplest probability questions. What explains this apparent paradox? How can a supposedly Bayesian brain reason so poorly with probabilities? In this paper, we propose a direct and perhaps unexpected answer: that Bayesian brains need not represent or calculate probabilities at all and are, indeed, poorly adapted to do so...
December 2016: Trends in Cognitive Sciences
https://www.readbyqxmd.com/read/28323852/extraction-of-features-from-sleep-eeg-for-bayesian-assessment-of-brain-development
#17
Vitaly Schetinin, Livija Jakaite
Brain development can be evaluated by experts analysing age-related patterns in sleep electroencephalograms (EEG). Natural variations in the patterns, noise, and artefacts affect the evaluation accuracy as well as experts' agreement. The knowledge of predictive posterior distribution allows experts to estimate confidence intervals within which decisions are distributed. Bayesian approach to probabilistic inference has provided accurate estimates of intervals of interest. In this paper we propose a new feature extraction technique for Bayesian assessment and estimation of predictive distribution in a case of newborn brain development assessment...
2017: PloS One
https://www.readbyqxmd.com/read/28323161/seeg-dipole-source-localization-based-on-an-empirical-bayesian-approach-taking-into-account-forward-model-uncertainties
#18
S Le Cam, R Ranta, V Caune, G Korats, L Koessler, L Maillard, V Louis-Dorr
Electromagnetic brain source localization consists in the inversion of a forward model based on a limited number of potential measurements. A wide range of methods has been developed to regularize this severely ill-posed problem and to reduce the solution space, imposing spatial smoothness, anatomical constraint or sparsity of the activated source map. This last criteria, based on physiological assumptions stating that in some particular events (e.g., epileptic spikes, evoked potential) few focal area of the brain are simultaneously actives, has gained more and more interest...
March 18, 2017: NeuroImage
https://www.readbyqxmd.com/read/28316255/a-bayesian-double-fusion-model-for-resting-state-brain-connectivity-using-joint-functional-and-structural-data
#19
Hakmook Kang, Hernando Ombao, Christopher Fonnesbeck, Zhaohua Ding, Victoria L Morgan
Current approaches separately analyze concurrently acquired diffusion tensor imaging (DTI) and functional magnetic resonance imaging (fMRI) data. The primary limitation of these approaches is that they do not take advantage of the information from DTI that could potentially enhance estimation of resting-state functional connectivity (FC) between brain regions. To overcome this limitation, we develop a Bayesian hierarchical spatiotemporal model that incorporates structural connectivity (SC) into estimating FC...
April 24, 2017: Brain Connectivity
https://www.readbyqxmd.com/read/28297889/time-varying-coupling-functions-dynamical-inference-and-cause-of-synchronization-transitions
#20
Tomislav Stankovski
Interactions in nature can be described by their coupling strength, direction of coupling, and coupling function. The coupling strength and directionality are relatively well understood and studied, at least for two interacting systems; however, there can be a complexity in the interactions uniquely dependent on the coupling functions. Such a special case is studied here: synchronization transition occurs only due to the time variability of the coupling functions, while the net coupling strength is constant throughout the observation time...
February 2017: Physical Review. E
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