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Granger causality

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https://www.readbyqxmd.com/read/28079528/assessing-the-evolution-of-redundancy-synergy-of-spontaneous-variability-regulation-with-age
#1
Alberto Porta, Vlasta Bari, Beatrice De Maria, Natália Maria Perseguini, Juliana Milan, Patricia Rehder-Santos, Vinícius Minatel, Anielle Takahashi, Aparecida Catai
We exploited a model-based Wiener-Granger causality method in the information domain for the evaluation of the transfer entropy (TE) and interaction TE (ITE), the latter taken as a measure of the net balance between redundancy and synergy, to describe the interactions between the spontaneous variability of heart period (HP) and systolic arterial pressure (SAP) and the effect of respiration (R) on both variables. Cardiac control was typified via the genuine TE from SAP to HP, that from R to HP, and the ITE from SAP and R to HP, while vascular control was characterized via the genuine TE from HP to SAP, that from R to SAP, and the ITE from HP and R to SAP...
January 12, 2017: Physiological Measurement
https://www.readbyqxmd.com/read/28077184/abnormalities-in-the-effective-connectivity-of-visuothalamic-circuitry-in-schizophrenia
#2
S J Iwabuchi, L Palaniyappan
BACKGROUND: Sensory-processing deficits appear crucial to the clinical expression of symptoms of schizophrenia. The visual cortex displays both dysconnectivity and aberrant spontaneous activity in patients with persistent symptoms and cognitive deficits. In this paper, we examine visual cortex in the context of the remerging notion of thalamic dysfunction in schizophrenia. We examined specific regional and longer-range abnormalities in sensory and thalamic circuits in schizophrenia, and whether these patterns are strong enough to discriminate symptomatic patients from controls...
January 12, 2017: Psychological Medicine
https://www.readbyqxmd.com/read/28065836/learning-effective-connectivity-from-fmri-using-autoregressive-hidden-markov-model-with-missing-data
#3
Shilpa Dang, Santanu Chaudhury, Brejesh Lall, Prasun Kumar Roy
BACKGROUND: Effective connectivity (EC) analysis of neuronal groups using fMRI delivers insights about functional-integration. However, fMRI signal has low-temporal resolution due to down-sampling and indirectly measures underlying neuronal activity. NEW METHOD: The aim is to address above issues for more reliable EC estimates. This paper proposes use of autoregressive hidden Markov model with missing data (AR-HMM-md) in dynamically multi-linked (DML) framework for learning EC using multiple fMRI time series...
January 5, 2017: Journal of Neuroscience Methods
https://www.readbyqxmd.com/read/27977564/vector-autoregressive-models-and-granger-causality-in-time-series-analysis-in-nursing-research-dynamic-changes-among-vital-signs-prior-to-cardiorespiratory-instability-events-as-an-example
#4
Eliezer Bose, Marilyn Hravnak, Susan M Sereika
BACKGROUND: Patients undergoing continuous vital sign monitoring (heart rate [HR], respiratory rate [RR], pulse oximetry [SpO2]) in real time display interrelated vital sign changes during situations of physiological stress. Patterns in this physiological cross-talk could portend impending cardiorespiratory instability (CRI). Vector autoregressive (VAR) modeling with Granger causality tests is one of the most flexible ways to elucidate underlying causal mechanisms in time series data...
January 2017: Nursing Research
https://www.readbyqxmd.com/read/27967128/testing-for-causality-in-reconstructed-state-spaces-by-an-optimized-mixed-prediction-method
#5
Anna Krakovská, Filip Hanzely
In this study, a method of causality detection was designed to reveal coupling between dynamical systems represented by time series. The method is based on the predictions in reconstructed state spaces. The results of the proposed method were compared with outcomes of two other methods, the Granger VAR test of causality and the convergent cross-mapping. We used two types of test data. The first test example is a unidirectional connection of chaotic systems of Rössler and Lorenz type. The second one, the fishery model, is an example of two correlated observables without a causal relationship...
November 2016: Physical Review. E
https://www.readbyqxmd.com/read/27967120/information-flow-and-causality-as-rigorous-notions-ab-initio
#6
X San Liang
Information flow or information transfer the widely applicable general physics notion can be rigorously derived from first principles, rather than axiomatically proposed as an ansatz. Its logical association with causality is firmly rooted in the dynamical system that lies beneath. The principle of nil causality that reads, an event is not causal to another if the evolution of the latter is independent of the former, which transfer entropy analysis and Granger causality test fail to verify in many situations, turns out to be a proven theorem here...
November 2016: Physical Review. E
https://www.readbyqxmd.com/read/27966491/a-lateralized-functional-auditory-network-is-involved-in-anuran-sexual-selection
#7
Fei Xue, Guangzhan Fang, Xizi Yue, Ermi Zhao, Steven E Brauth, Yezhong Tang
Right ear advantage (REA) exists in many land vertebrates in which the right ear and left hemisphere preferentially process conspecific acoustic stimuli such as those related to sexual selection. Although ecological and neural mechanisms for sexual selection have been widely studied, the brain networks involved are still poorly understood. In this study we used multi-channel electroencephalographic data in combination with Granger causal connectivity analysis to demonstrate, for the first time, that auditory neural network interconnecting the left and right midbrain and forebrain function asymmetrically in the Emei music frog (Babina daunchina), an anuran species which exhibits REA...
December 2016: Journal of Biosciences
https://www.readbyqxmd.com/read/27924281/causality-analysis-detects-the-regulatory-role-of-maternal-effect-genes-in-the-early-drosophila-embryo
#8
Zara Ghodsi, Xu Huang, Hossein Hassani
In developmental studies, inferring regulatory interactions of segmentation genetic network play a vital role in unveiling the mechanism of pattern formation. As such, there exists an opportune demand for theoretical developments and new mathematical models which can result in a more accurate illustration of this genetic network. Accordingly, this paper seeks to extract the meaningful regulatory role of the maternal effect genes using a variety of causality detection techniques and to explore whether these methods can suggest a new analytical view to the gene regulatory networks...
March 2017: Genomics Data
https://www.readbyqxmd.com/read/27915993/directed-functional-connectivity-of-posterior-cingulate-cortex-and-whole-brain-in-alzheimer-s-disease-and-mild-cognitive-impairment
#9
Enyan Yu, Zhengluan Liao, Dewang Mao, Qi Zhang, Gongjun Ji, Yumei Li, Zhongxiang Ding
BACKGROUND: Impaired functional connectivity in the default mode network (DMN) is supposedly involved in Alzheimer's disease (AD) progression. The posterior cingulate cortex (PCC) might be an imaging marker for monitoring AD progression. OBJECTIVE: To investigate the alterations in the directed functional connectivity between the PCC and whole brain in patients with AD, patients with mild cognitive impairment (MCI), and healthy controls. METHODS: A total of 116 enrolled participants were divided into three groups: AD (n=32), MCI (n=26), and controls (n=58)...
December 1, 2016: Current Alzheimer Research
https://www.readbyqxmd.com/read/27913167/gamma-band-directional-interactions-between-basal-forebrain-and-visual-cortex-during-wake-and-sleep-states
#10
Jayakrishnan Nair, Arndt-Lukas Klaassen, Jordan Poirot, Alexei Vyssotski, Björn Rasch, Gregor Rainer
The basal forebrain (BF) is an important regulator of cortical excitability and responsivity to sensory stimuli, and plays a major role in wake-sleep regulation. While the impact of BF on cortical EEG or LFP signals has been extensively documented, surprisingly little is known about LFP activity within BF. Based on bilateral recordings from rats in their home cage, we describe endogenous LFP oscillations in the BF during quiet wakefulness, rapid eye movement (REM) and slow wave sleep (SWS) states. Using coherence and Granger causality methods, we characterize directional influences between BF and visual cortex (VC) during each of these states...
September 2016: Journal of Physiology, Paris
https://www.readbyqxmd.com/read/27905073/critical-comments-on-eeg-sensor-space-dynamical-connectivity-analysis
#11
Frederik Van de Steen, Luca Faes, Esin Karahan, Jitkomut Songsiri, Pedro A Valdes-Sosa, Daniele Marinazzo
Many different analysis techniques have been developed and applied to EEG recordings that allow one to investigate how different brain areas interact. One particular class of methods, based on the linear parametric representation of multiple interacting time series, is widely used to study causal connectivity in the brain. However, the results obtained by these methods should be interpreted with great care. The goal of this paper is to show, both theoretically and using simulations, that results obtained by applying causal connectivity measures on the sensor (scalp) time series do not allow interpretation in terms of interacting brain sources...
November 30, 2016: Brain Topography
https://www.readbyqxmd.com/read/27880004/causal-relationships-among-neurons-of-the-nucleus-incertus-and-the-hippocampal-theta-activity-in-the-rat
#12
Sergio Martínez-Bellver, Ana Cervera-Ferri, Aina Luque-García, Joana Martínez-Ricós, Alfonso Valverde-Navarro, Manuel Bataller, Juan Guerrero, Vicent Teruel-Marti
In recent years, a body of evidence has shown that the nucleus incertus (NI), in the dorsal tegmental pons, is a key node of the brainstem circuitry involved in hippocampal theta rhythmicity. Ascending reticular brainstem system activation evokes hippocampal theta rhythm with coupled neuronal activity in the NI. In a recent paper, we showed three populations of neurons in the NI with differential firings during hippocampal theta activation. The objective of this work is to better evaluate the causal relationship between the activity of NI neurons and the hippocampus during theta activation in order to further understand the role of the NI in the theta network...
November 23, 2016: Journal of Physiology
https://www.readbyqxmd.com/read/27875123/synergetic-and-redundant-information-flow-detected-by-unnormalized-granger-causality-application-to-resting-state-fmri
#13
Sebastiano Stramaglia, Leonardo Angelini, Guorong Wu, Jesus M Cortes, Luca Faes, Daniele Marinazzo
OBJECTIVES: We develop a framework for the analysis of synergy and redundancy in the pattern of information flow between subsystems of a complex network. METHODS: The presence of redundancy and/or synergy in multivariate time series data renders difficulty to estimate the neat flow of information from each driver variable to a given target. We show that adopting an unnormalized definition of Granger causality, one may put in evidence redundant multiplets of variables influencing the target by maximizing the total Granger causality to a given target, over all the possible partitions of the set of driving variables...
December 2016: IEEE Transactions on Bio-medical Engineering
https://www.readbyqxmd.com/read/27868393/atypical-effective-connectivity-of-thalamo-cortical-circuits-in-autism-spectrum-disorder
#14
Heng Chen, Lucina Q Uddin, Youxue Zhang, Xujun Duan, Huafu Chen
Autism spectrum disorder (ASD) is a neurodevelopment disorder characterized by atypical connectivity within and across multiple brain systems. We aimed to explore information transmission from the sensory periphery to information processing centers of the brain across thalamo-cortical circuits in ASD. A large multicenter dataset from the autism brain imaging data exchange was utilized. A thalamus template derived from the Automatic Anatomic Labeling atlas was subdivided into six subregions corresponding to six cortical regions using a "winner-takes-all" strategy...
November 2016: Autism Research: Official Journal of the International Society for Autism Research
https://www.readbyqxmd.com/read/27867351/advice-taking-from-humans-and-machines-an-fmri-and-effective-connectivity-study
#15
Kimberly Goodyear, Raja Parasuraman, Sergey Chernyak, Poornima Madhavan, Gopikrishna Deshpande, Frank Krueger
With new technological advances, advice can come from different sources such as machines or humans, but how individuals respond to such advice and the neural correlates involved need to be better understood. We combined functional MRI and multivariate Granger causality analysis with an X-ray luggage-screening task to investigate the neural basis and corresponding effective connectivity involved with advice utilization from agents framed as experts. Participants were asked to accept or reject good or bad advice from a human or machine agent with low reliability (high false alarm rate)...
2016: Frontiers in Human Neuroscience
https://www.readbyqxmd.com/read/27856312/empirical-validation-of-directed-functional-connectivity
#16
Ravi D Mill, Anto Bagic, Andreea Bostan, Walter Schneider, Michael W Cole
Mapping directions of influence in the human brain connectome represents the next phase in understanding its functional architecture. However, a host of methodological uncertainties have impeded the application of directed connectivity methods, which have primarily been validated via "ground truth" connectivity patterns embedded in simulated functional MRI (fMRI) and magneto-/electro-encephalography (MEG/EEG) datasets. Such simulations rely on many generative assumptions, and we hence utilized a different strategy involving empirical data in which a ground truth directed connectivity pattern could be anticipated with confidence...
November 14, 2016: NeuroImage
https://www.readbyqxmd.com/read/27846290/altered-effective-connectivity-of-the-primary-motor-cortex-in-stroke-a-resting-state-fmri-study-with-granger-causality-analysis
#17
Zhiyong Zhao, Xiangmin Wang, Mingxia Fan, Dazhi Yin, Limin Sun, Jie Jia, Chaozheng Tang, Xiaohui Zheng, Yuwei Jiang, Jie Wu, Jiayu Gong
The primary motor cortex (M1) is often abnormally recruited in stroke patients with motor disabilities. However, little is known about the alterations in the causal connectivity of M1 following stroke. The purpose of the present study was to investigate whether the effective connectivity of the ipsilesional M1 is disturbed in stroke patients who show different outcomes in hand motor function. 23 patients with left-hemisphere subcortical stroke were selected and divided into two subgroups: partially paralyzed hands (PPH) and completely paralyzed hands (CPH)...
2016: PloS One
https://www.readbyqxmd.com/read/27833547/new-insights-into-signed-path-coefficient-granger-causality-analysis
#18
Jian Zhang, Chong Li, Tianzi Jiang
Granger causality analysis, as a time series analysis technique derived from econometrics, has been applied in an ever-increasing number of publications in the field of neuroscience, including fMRI, EEG/MEG, and fNIRS. The present study mainly focuses on the validity of "signed path coefficient Granger causality," a Granger-causality-derived analysis method that has been adopted by many fMRI researches in the last few years. This method generally estimates the causality effect among the time series by an order-1 autoregression, and defines a positive or negative coefficient as an "excitatory" or "inhibitory" influence...
2016: Frontiers in Neuroinformatics
https://www.readbyqxmd.com/read/27833546/measures-of-coupling-between-neural-populations-based-on-granger-causality-principle
#19
REVIEW
Maciej Kaminski, Aneta Brzezicka, Jan Kaminski, Katarzyna J Blinowska
This paper shortly reviews the measures used to estimate neural synchronization in experimental settings. Our focus is on multivariate measures of dependence based on the Granger causality (G-causality) principle, their applications and performance in respect of robustness to noise, volume conduction, common driving, and presence of a "weak node." Application of G-causality measures to EEG, intracranial signals and fMRI time series is addressed. G-causality based measures defined in the frequency domain allow the synchronization between neural populations and the directed propagation of their electrical activity to be determined...
2016: Frontiers in Computational Neuroscience
https://www.readbyqxmd.com/read/27832153/inferring-weighted-directed-association-network-from-multivariate-time-series-with-a-synthetic-method-of-partial-symbolic-transfer-entropy-spectrum-and-granger-causality
#20
Yanzhu Hu, Huiyang Zhao, Xinbo Ai
Complex network methodology is very useful for complex system explorer. However, the relationships among variables in complex system are usually not clear. Therefore, inferring association networks among variables from their observed data has been a popular research topic. We propose a synthetic method, named small-shuffle partial symbolic transfer entropy spectrum (SSPSTES), for inferring association network from multivariate time series. The method synthesizes surrogate data, partial symbolic transfer entropy (PSTE) and Granger causality...
2016: PloS One
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