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https://www.readbyqxmd.com/read/28614395/eeg-based-motor-network-biomarkers-for-identifying-target-patients-with-stroke-for-upper-limb-rehabilitation-and-its-construct-validity
#1
Chun-Chuan Chen, Si-Huei Lee, Wei-Jen Wang, Yu-Chen Lin, Mu-Chun Su
Rehabilitation is the main therapeutic approach for reducing poststroke functional deficits in the affected upper limb; however, significant between-patient variability in rehabilitation efficacy indicates the need to target patients who are likely to have clinically significant improvement after treatment. Many studies have determined robust predictors of recovery and treatment gains and yielded many great results using linear approachs. Evidence has emerged that the nonlinearity is a crucial aspect to study the inter-areal communication in human brains and abnormality of oscillatory activities in the motor system is linked to the pathological states...
2017: PloS One
https://www.readbyqxmd.com/read/28606210/impulsivity-as-a-mechanism-linking-child-abuse-and-neglect-with-substance-use-in-adolescence-and-adulthood
#2
Assaf Oshri, Steve M Kogan, Josephine A Kwon, K A S Wickrama, Lauren Vanderbroek, Abraham A Palmer, James MacKillop
Emerging developmental perspectives suggest that adverse rearing environments promote neurocognitive adaptations that heighten impulsivity and increase vulnerability to risky behavior. Although studies document links between harsh rearing environments and impulsive behavior on substance use, the developmental hypothesis that impulsivity acts as mechanism linking adverse rearing environments to downstream substance use remains to be investigated. The present study investigated the role of impulsivity in linking child abuse and neglect with adult substance use using data from (a) a longitudinal sample of youth (Study 1, N = 9,421) and (b) a cross-sectional sample of adults (Study 2, N = 1,011)...
June 13, 2017: Development and Psychopathology
https://www.readbyqxmd.com/read/28603919/dynamic-brain-connectivity-is-a-better-predictor-of-ptsd-than-static-connectivity
#3
Changfeng Jin, Hao Jia, Pradyumna Lanka, D Rangaprakash, Lingjiang Li, Tianming Liu, Xiaoping Hu, Gopikrishna Deshpande
Using resting-state functional magnetic resonance imaging, we test the hypothesis that subjects with post-traumatic stress disorder (PTSD) are characterized by reduced temporal variability of brain connectivity compared to matched healthy controls. Specifically, we test whether PTSD is characterized by elevated static connectivity, coupled with decreased temporal variability of those connections, with the latter providing greater sensitivity toward the pathology than the former. Static functional connectivity (FC; nondirectional zero-lag correlation) and static effective connectivity (EC; directional time-lagged relationships) were obtained over the entire brain using conventional models...
June 12, 2017: Human Brain Mapping
https://www.readbyqxmd.com/read/28602997/neural-mechanisms-underlying-valence-inferences-to-sound-the-role-of-the-right-angular-gyrus
#4
Fernando Bravo, Ian Cross, Sarah Hawkins, Nadia Gonzalez, Jorge Docampo, Claudio Bruno, Emmanuel Andreas Stamatakis
We frequently infer others' intentions based on non-verbal auditory cues. Although the brain underpinnings of social cognition have been extensively studied, no empirical work has yet examined the impact of musical structure manipulation on the neural processing of emotional valence during mental state inferences. We used a novel sound-based theory-of-mind paradigm in which participants categorized stimuli of different sensory dissonance level in terms of positive/negative valence. Whilst consistent with previous studies which propose facilitated encoding of consonances, our results demonstrated that distinct levels of consonance/dissonance elicited differential influences on the right angular gyrus, an area implicated in mental state attribution and attention reorienting processes...
June 8, 2017: Neuropsychologia
https://www.readbyqxmd.com/read/28602817/on-memories-neural-ensembles-and-mental-flexibility
#5
Dimitris A Pinotsis, Scott L Brincat, Earl K Miller
Memories are assumed to be represented by groups of co-activated neurons, called neural ensembles. Describing ensembles is a challenge: complexity of the underlying micro-circuitry is immense. Current approaches use a piecemeal fashion, focusing on single neurons and employing local measures like pairwise correlations. We introduce an alternative approach that identifies ensembles and describes the effective connectivity between them in a holistic fashion. It also links the oscillatory frequencies observed in ensembles with the spatial scales at which activity is expressed...
June 9, 2017: NeuroImage
https://www.readbyqxmd.com/read/28597101/erratum-to-gaba-content-within-medial-prefrontal-cortex-predicts-the-variability-of-fronto-limbic-effective-connectivity
#6
Stefano Delli Pizzi, Piero Chiacchiaretta, Dante Mantini, Giovanna Bubbico, Richard A Edden, Marco Onofrj, Antonio Ferretti, Laura Bonanni
No abstract text is available yet for this article.
June 8, 2017: Brain Structure & Function
https://www.readbyqxmd.com/read/28588458/modes-of-effective-connectivity-within-cortical-pathways-are-distinguished-for-different-categories-of-visual-context-an-fmri-study
#7
Qiong Wu, Jinglong Wu, Shigeko Takahashi, Qiang Huang, Hongzan Sun, Qiyong Guo, Yoshio Ohtani, Yoshimichi Ejima, Xu Zhang, Chunlin Li, Tianyi Yan
Context contributes to accurate and efficient information processing. To reveal the dynamics of the neural mechanisms that underlie the processing of visual contexts during the recognition of color, shape, and 3D structure of objects, we carried out functional magnetic resonance imaging (fMRI) of subjects while judging the contextual validity of the three visual contexts. Our results demonstrated that the modes of effective connectivity in the cortical pathways, as well as the patterns of activation in these pathways, were dynamical depending on the nature of the visual contexts...
2017: Frontiers in Behavioral Neuroscience
https://www.readbyqxmd.com/read/28578155/prefrontal-parietal-effective-connectivity-during-working-memory-in-older-adults
#8
Stephan Heinzel, Robert C Lorenz, Quynh-Lam Duong, Michael A Rapp, Lorenz Deserno
Theoretical models and preceding studies have described age-related alterations in neuronal activation of frontoparietal regions in a working memory (WM) load-dependent manner. However, to date, underlying neuronal mechanisms of these WM load-dependent activation changes in aging remain poorly understood. The aim of this study was to investigate these mechanisms in terms of effective connectivity by application of dynamic causal modeling with Bayesian Model Selection. Eighteen healthy younger (age: 20-32 years) and 32 older (60-75 years) participants performed an n-back task with 3 WM load levels during functional magnetic resonance imaging (fMRI)...
May 10, 2017: Neurobiology of Aging
https://www.readbyqxmd.com/read/28576731/quantify-neuromagnetic-network-changes-from-pre-ictal-to-ictal-activities-in-absence-seizures
#9
Caiyun Wu, Jing Xiang, Jintao Sun, Shuyang Huang, Lu Tang, Ailiang Miao, Yuchen Zhou, Qiqi Chen, Zheng Hu, Xiaoshan Wang
OBJECTIVE: The cortico-thalamo-cortical network plays a key role in childhood absence epilepsy (CAE). However, the exact interaction between the cortex and the thalamus remains incompletely understood. This study aimed to investigate the dynamic changes of frequency-dependent neural networks during the initialization of absence seizures. METHODS: Magnetoencephalography data from 14 patients with CAE were recorded during and between seizures at a sampling rate of 6000Hz and analyzed in seven frequency bands...
May 31, 2017: Neuroscience
https://www.readbyqxmd.com/read/28572034/decreased-middle-temporal-gyrus-connectivity-in-the-language-network-in-schizophrenia-patients-with-auditory-verbal-hallucinations
#10
Linchuan Zhang, Baojuan Li, Huaning Wang, Liang Li, Qimei Liao, Yang Liu, Xianghong Bao, Wenlei Liu, Hong Yin, Hongbing Lu, Qingrong Tan
As the most common symptoms of schizophrenia, the long-term persistence of obstinate auditory verbal hallucinations (AVHs) brings about great mental pain to patients. Neuroimaging studies of schizophrenia have indicated that AVHs were associated with altered functional and structural connectivity within the language network. However, effective connectivity that could reflect directed information flow within this network and is of great importance to understand the neural mechanisms of the disorder remains largely unknown...
May 29, 2017: Neuroscience Letters
https://www.readbyqxmd.com/read/28559793/initial-validation-for-the-estimation-of-resting-state-fmri-effective-connectivity-by-a-generalization-of-the-correlation-approach
#11
Nan Xu, R Nathan Spreng, Peter C Doerschuk
Resting-state functional MRI (rs-fMRI) is widely used to noninvasively study human brain networks. Network functional connectivity is often estimated by calculating the timeseries correlation between blood-oxygen-level dependent (BOLD) signal from different regions of interest (ROIs). However, standard correlation cannot characterize the direction of information flow between regions. In this paper, we introduce and test a new concept, prediction correlation, to estimate effective connectivity in functional brain networks from rs-fMRI...
2017: Frontiers in Neuroscience
https://www.readbyqxmd.com/read/28559378/parallel-regulation-of-memory-and-emotion-supports-the-suppression-of-intrusive-memories
#12
Pierre Gagnepain, Justin Hulbert, Michael C Anderson
Intrusive memories often take the form of distressing images that emerge into a person's awareness, unbidden. A fundamental goal of clinical neuroscience is to understand the mechanisms allowing people to control these memory intrusions and reduce their emotional impact. Mnemonic control engages a right fronto-parietal network that interrupts episodic retrieval by modulating hippocampal activity; less is known, however, about how this mechanism contributes to affect regulation. Here we report evidence in humans (males and females) that stopping episodic retrieval to suppress an unpleasant image triggers parallel inhibition of mnemonic and emotional content...
May 30, 2017: Journal of Neuroscience: the Official Journal of the Society for Neuroscience
https://www.readbyqxmd.com/read/28495368/the-dynamic-programming-high-order-dynamic-bayesian-networks-learning-for-identifying-effective-connectivity-in-human-brain-from-fmri
#13
Shilpa Dang, Santanu Chaudhury, Brejesh Lall, Prasun Kumar Roy
BACKGROUND: Determination of effective connectivity (EC) among brain regions using fMRI is helpful in understanding the underlying neural mechanisms. Dynamic Bayesian Networks (DBNs) are an appropriate class of probabilistic graphical temporal-models that have been used in past to model EC from fMRI, specifically order-one. NEW-METHOD: High-order DBNs (HO-DBNs) have still not been explored for fMRI data. A fundamental problem faced in the structure-learning of HO-DBN is high computational-burden and low accuracy by the existing heuristic search techniques used for EC detection from fMRI...
June 15, 2017: Journal of Neuroscience Methods
https://www.readbyqxmd.com/read/28469529/protected-areas-in-the-world-s-ecoregions-how-well-connected-are-they
#14
Santiago Saura, Lucy Bastin, Luca Battistella, Andrea Mandrici, Grégoire Dubois
Protected areas (PAs) are the main instrument for biodiversity conservation, which has triggered the development of numerous indicators and assessments on their coverage, performance and efficiency. The connectivity of the PA networks at a global scale has however been much less explored; previous studies have either focused on particular regions of the world or have only considered some types of PAs. Here we present, and globally assess, ProtConn, an indicator of PA connectivity that (i) quantifies the percentage of a study region covered by protected connected lands, (ii) can be partitioned in several components depicting different categories of land (unprotected, protected or transboundary) through which movement between protected locations may occur, (iii) is easy to communicate, to compare with PA coverage and to use in the assessment of global targets for PA systems...
May 2017: Ecological Indicators
https://www.readbyqxmd.com/read/28469187/habitat-connectivity-and-in-stream-vegetation-control-temporal-variability-of-benthic-invertebrate-communities
#15
K-L Huttunen, H Mykrä, J Oksanen, A Astorga, R Paavola, T Muotka
One of the key challenges to understanding patterns of β diversity is to disentangle deterministic patterns from stochastic ones. Stochastic processes may mask the influence of deterministic factors on community dynamics, hindering identification of the mechanisms causing variation in community composition. We studied temporal β diversity (among-year dissimilarity) of macroinvertebrate communities in near-pristine boreal streams across 14 years. To assess whether the observed β diversity deviates from that expected by chance, and to identify processes (deterministic vs...
May 3, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28467487/is-functional-brain-connectivity-atypical-in-autism-a-systematic-review-of-eeg-and-meg-studies
#16
Christian O'Reilly, John D Lewis, Mayada Elsabbagh
BACKGROUND: Although it is well recognized that autism is associated with altered patterns of over- and under-connectivity, specifics are still a matter of debate. Little has been done so far to synthesize available literature using whole-brain electroencephalography (EEG) and magnetoencephalography (MEG) recordings. OBJECTIVES: 1) To systematically review the literature on EEG/MEG functional and effective connectivity in autism spectrum disorder (ASD), 2) to synthesize and critically appraise findings related with the hypothesis that ASD is characterized by long-range underconnectivity and local overconnectivity, and 3) to provide, based on the literature, an analysis of tentative factors that are likely to mediate association between ASD and atypical connectivity (e...
2017: PloS One
https://www.readbyqxmd.com/read/28456171/on-the-role-of-the-entorhinal-cortex-in-the-effective-connectivity-of-the-hippocampal-formation
#17
Víctor J López-Madrona, Fernanda S Matias, Ernesto Pereda, Santiago Canals, Claudio R Mirasso
Inferring effective connectivity from neurophysiological data is a challenging task. In particular, only a finite (and usually small) number of sites are simultaneously recorded, while the response of one of these sites can be influenced by other sites that are not being recorded. In the hippocampal formation, for instance, the connections between areas CA1-CA3, the dentate gyrus (DG), and the entorhinal cortex (EC) are well established. However, little is known about the relations within the EC layers, which might strongly affect the resulting effective connectivity estimations...
April 2017: Chaos
https://www.readbyqxmd.com/read/28454106/different-patterns-of-age-related-central-olfactory-decline-in-men-and-women-as-quantified-by-olfactory-fmri
#18
Brittany Martinez, Prasanna Karunanayaka, Jianli Wang, Michael J Tobia, Megha Vasavada, Paul J Eslinger, Qing X Yang
Age-related olfactory decline, or presbyosmia, is a prevalent condition with potentially devastating consequences on both quality of life and safety. Despite clear evidence for this decline, it is unknown whether presbyosmia is sex-dependent and also whether it is due to central or peripheral olfactory system deterioration. Therefore, the goals of this study were to investigate the neurofunctional substrate of olfactory decline and examine its relationship to age and sex in thirty-seven (18 women, 19 men) healthy older participants using olfactory functional MRI (fMRI)...
April 8, 2017: Oncotarget
https://www.readbyqxmd.com/read/28448272/automated-network-analysis-to-measure-brain-effective-connectivity-estimated-from-eeg-data-of-patients-with-alcoholism
#19
Youngoh Bae, Byeong Wook Yoo, Jung Chan Lee, Hee Chan Kim
OBJECTIVE: Detection and diagnosis based on extracting features and classification using electroencephalography (EEG) signals are being studied vigorously. A network analysis of time series EEG signal data is one of many techniques that could help study brain functions. In this study, we analyze EEG to diagnose alcoholism. APPROACH: We propose a novel methodology to estimate the differences in the status of the brain based on EEG data of normal subjects and data from alcoholics by computing many parameters stemming from effective network using Granger causality...
May 2017: Physiological Measurement
https://www.readbyqxmd.com/read/28438665/effective-connectivity-gateways-to-the-theory-of-mind-network-in-processing-communicative-intention
#20
Marco Tettamanti, Matilde M Vaghi, Bruno G Bara, Stefano F Cappa, Ivan Enrici, Mauro Adenzato
An Intention Processing Network (IPN), involving the medial prefrontal cortex, precuneus, bilateral posterior superior temporal sulcus, and temporoparietal junctions, plays a fundamental role in comprehending intentions underlying action goals. In a previous fMRI study, we showed that, depending on the linguistic or extralinguistic (gestural) modality used to convey the intention, the IPN is complemented by activation of additional brain areas, reflecting distinct modality-specific input gateways to the IPN...
April 22, 2017: NeuroImage
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