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"Dynamic functional connectivity"

Vesna Prčkovska, Willem Huijbers, Aaron Schultz, Laura Ortiz-Teran, Cleofe Peña-Gomez, Pablo Villoslada, Keith Johnson, Reisa Sperling, Jorge Sepulcre
OBJECTIVES AND DESIGN: Neuronal responses adapt to familiar and repeated sensory stimuli. Enhanced synchrony across wide brain systems has been postulated as a potential mechanism for this adaptation phenomenon. Here, we used recently developed graph theory methods to investigate hidden connectivity features of dynamic synchrony changes during a visual repetition paradigm. Particularly, we focused on strength connectivity changes occurring at local and distant brain neighborhoods. PRINCIPAL OBSERVATIONS: We found that connectivity reorganization in visual modal cortex-such as local suppressed connectivity in primary visual areas and distant suppressed connectivity in fusiform areas-is accompanied by enhanced local and distant connectivity in higher cognitive processing areas in multimodal and association cortex...
December 28, 2016: Human Brain Mapping
William Hedley Thompson, Peter Fransson
The brain is organized into large scale spatial networks that can be detected during periods of rest using fMRI. The brain is also a dynamic organ with activity that changes over time. We developed a method and investigated properties where the connections as a function of time are derived and quantified. The point based method (PBM) presented here derives covariance matrices after clustering individual time points based upon their global spatial pattern. This method achieved increased temporal sensitivity, together with temporal network theory, allowed us to study functional integration between resting-state networks...
December 19, 2016: Scientific Reports
Xiangpeng Wang, Wenwen Zhang, Yujing Sun, Min Hu, Antao Chen
Aberrant functional interactions between several large-scale networks, especially the central executive network (CEN), the default mode network (DMN) and the salience network (SN), have been postulated as core pathophysiologic features of schizophrenia; however, the attributing factors of which remain unclear. The study employed resting-state fMRI with 77 participants (42 patients and 35 controls). We performed dynamic functional connectivity (DFC) and functional connectivity (FC) analyses to explore the connectivity patterns of these networks...
December 2016: Neuropsychologia
Benjamin W Mooneyham, Michael D Mrazek, Alissa J Mrazek, Kaita L Mrazek, Dawa T Phillips, Jonathan W Schooler
During tasks that require continuous engagement, the mind alternates between mental states of focused attention and mind-wandering. Existing research has assessed the functional connectivity of intrinsic brain networks underlying the experience and training of these mental states using "static" approaches that assess connectivity across an entire task. To disentangle the functional connectivity between brain regions as the mind fluctuates between discrete brain states, we employed a dynamic functional connectivity approach that characterized brain activity using a sliding window...
October 25, 2016: Journal of Cognitive Neuroscience
Tanya T Nguyen, Sanja Kovacevic, Sheena I Dev, Kun Lu, Thomas T Liu, Lisa T Eyler
OBJECTIVE: Disturbances in functional connectivity have been suggested to contribute to cognitive and emotion processing deficits observed in bipolar disorder (BD). Functional connectivity between medial prefrontal cortex (mPFC) and other brain regions may be particularly abnormal. The goal of the present study was to characterize the temporal dynamics of the default mode network (DMN) connectivity in BD and examine its association with cognition. METHOD: In a preliminary study, euthymic BD (n = 15) and healthy comparison (HC, n = 19) participants underwent resting-state functional MRI, using high-resolution sequences adapted from the Human Connectome Project, and completed neuropsychological measures of processing speed and executive function...
January 2017: Neuropsychology
Zewei Wang, Qing Yang, Li Min Chen
The goals of this study are to characterize the temporal dynamics of inter-regional connectivity of the brain in chronic headache (CH) patients versus their age/gender matched controls (CONCH, n=28 pairs), and to determine whether dynamic measures reveal additional features to static functional connectivity and correlate with psychometric scores. Cortical thickness and inter-regional resting state fMRI connectivity were quantified and compared between CH and CONCH groups. Six cortical regions of interest (ROI) pairs that exhibited correlated cortical thickness and static functional connectivity abnormalities were selected for temporal dynamic analysis...
October 14, 2016: Magnetic Resonance Imaging
Burak Akin, Hsu-Lei Lee, Jürgen Hennig, Pierre LeVan
Resting-state networks have become an important tool for the study of brain function. An ultra-fast imaging technique that allows to measure brain function, called Magnetic Resonance Encephalography (MREG), achieves an order of magnitude higher temporal resolution than standard echo-planar imaging (EPI). This new sequence helps to correct physiological artifacts and improves the sensitivity of the fMRI analysis. In this study, EPI is compared with MREG in terms of capability to extract resting-state networks...
October 3, 2016: Human Brain Mapping
Linda Douw, Daniel G Wakeman, Naoaki Tanaka, Hesheng Liu, Steven M Stufflebeam
The brain is a dynamic, flexible network that continuously reconfigures. However, the neural underpinnings of how state-dependent variability of dynamic functional connectivity (vdFC) relates to cognitive flexibility are unclear. We therefore investigated flexible functional connectivity during resting-state and task-state functional magnetic resonance imaging (rs-fMRI and t-fMRI, resp.) and performed separate, out-of-scanner neuropsychological testing. We hypothesize that state-dependent vdFC between the frontoparietal network (FPN) and the default mode network (DMN) relates to cognitive flexibility...
December 17, 2016: Neuroscience
Jeff Boissoneault, Janelle Letzen, Song Lai, Michael E Robinson, Roland Staud
Studies using arterial spin labelling (ASL) have shown that individuals with chronic fatigue syndrome (CFS) have decreased regional cerebral blood flow, which may be associated with changes in functional neural networks. Indeed, recent studies indicate disruptions in functional connectivity (FC) at rest in chronically fatigued patients including perturbations in static FC (sFC), that is average FC at rest between several brain regions subserving neurocognitive, motor and affect-related networks. Whereas sFC often provides information of functional network reorganization in chronic illnesses, investigations of temporal changes in functional connectivity between multiple brain areas may shed light on the dynamic characteristics of brain network activation associated with such maladies...
September 28, 2016: Clinical Physiology and Functional Imaging
Gideon Rosenthal, Olaf Sporns, Galia Avidan
Using the "face inversion effect", a hallmark of face perception, we examined network mechanisms supporting face representation by tracking functional magnetic resonance imaging (fMRI) stimulus-dependent dynamic functional connectivity within and between brain networks associated with the processing of upright and inverted faces. We developed a novel approach adapting the general linear model (GLM) framework classically used for univariate fMRI analysis to capture stimulus-dependent fMRI dynamic connectivity of the face network...
September 12, 2016: Cerebral Cortex
Ricardo Pio Monti, Romy Lorenz, Rodrigo M Braga, Christoforos Anagnostopoulos, Robert Leech, Giovanni Montana
Two novel and exciting avenues of neuroscientific research involve the study of task-driven dynamic reconfigurations of functional connectivity networks and the study of functional connectivity in real-time. While the former is a well-established field within neuroscience and has received considerable attention in recent years, the latter remains in its infancy. To date, the vast majority of real-time fMRI studies have focused on a single brain region at a time. This is due in part to the many challenges faced when estimating dynamic functional connectivity networks in real-time...
January 2017: Human Brain Mapping
Timothy O Laumann, Abraham Z Snyder, Anish Mitra, Evan M Gordon, Caterina Gratton, Babatunde Adeyemo, Adrian W Gilmore, Steven M Nelson, Jeff J Berg, Deanna J Greene, John E McCarthy, Enzo Tagliazucchi, Helmut Laufs, Bradley L Schlaggar, Nico U F Dosenbach, Steven E Petersen
Measurement of correlations between brain regions (functional connectivity) using blood oxygen level dependent (BOLD) fMRI has proven to be a powerful tool for studying the functional organization of the brain. Recently, dynamic functional connectivity has emerged as a major topic in the resting-state BOLD fMRI literature. Here, using simulations and multiple sets of empirical observations, we confirm that imposed task states can alter the correlation structure of BOLD activity. However, we find that observations of "dynamic" BOLD correlations during the resting state are largely explained by sampling variability...
September 2, 2016: Cerebral Cortex
Hilary A Marusak, Vince D Calhoun, Suzanne Brown, Laura M Crespo, Kelsey Sala-Hamrick, Ian H Gotlib, Moriah E Thomason
The human brain is highly dynamic, supporting a remarkable range of cognitive abilities that emerge over the course of development. While flexible and dynamic coordination between neural systems is firmly established for children, our understanding of brain functional organization in early life has been built largely on the implicit assumption that functional connectivity (FC) is static. Understanding the nature of dynamic neural interactions during development is a critical issue for cognitive neuroscience, with implications for neurodevelopmental pathologies that involve anomalies in brain connectivity...
January 2017: Human Brain Mapping
Chenhao Wang, Ju Lynn Ong, Amiya Patanaik, Juan Zhou, Michael W L Chee
Fluctuations in resting-state functional connectivity occur but their behavioral significance remains unclear, largely because correlating behavioral state with dynamic functional connectivity states (DCS) engages probes that disrupt the very behavioral state we seek to observe. Observing spontaneous eyelid closures following sleep deprivation permits nonintrusive arousal monitoring. During periods of low arousal dominated by eyelid closures, sliding-window correlation analysis uncovered a DCS associated with reduced within-network functional connectivity of default mode and dorsal/ventral attention networks, as well as reduced anticorrelation between these networks...
August 23, 2016: Proceedings of the National Academy of Sciences of the United States of America
Marion Sourty, Laurent Thoraval, Daniel Roquet, Jean-Paul Armspach, Jack Foucher, Frédéric Blanc
Exploring time-varying connectivity networks in neurodegenerative disorders is a recent field of research in functional MRI. Dementia with Lewy bodies (DLB) represents 20% of the neurodegenerative forms of dementia. Fluctuations of cognition and vigilance are the key symptoms of DLB. To date, no dynamic functional connectivity (DFC) investigations of this disorder have been performed. In this paper, we refer to the concept of connectivity state as a piecewise stationary configuration of functional connectivity between brain networks...
2016: Frontiers in Computational Neuroscience
Zainab Fatima, Natasha Kovacevic, Bratislav Misic, Anthony Randal McIntosh
Current neuroscientific research has shown that the brain reconfigures its functional interactions at multiple timescales. Here, we sought to link transient changes in functional brain networks to individual differences in behavioral and cognitive performance by using an active learning paradigm. Participants learned associations between pairs of unrelated visual stimuli by using feedback. Interindividual behavioral variability was quantified with a learning rate measure. By using a multivariate statistical framework (partial least squares), we identified patterns of network organization across multiple temporal scales (within a trial, millisecond; across a learning session, minute) and linked these to the rate of change in behavioral performance (fast and slow)...
June 29, 2016: Human Brain Mapping
Jianpo Su, Hui Shen, Ling-Li Zeng, Jian Qin, Zhening Liu, Dewen Hu
Previous static resting-state functional connectivity (FC) MRI (rs-fcMRI) studies have suggested certain heredity characteristics of schizophrenia. Recently, dynamic rs-fcMRI analysis, which can better characterize the time-varying nature of intrinsic activity and connectivity and may therefore unveil the special connectivity patterns that are always lost in static FC analysis, has shown a potential neuroendophenotype of schizophrenia. In this study, we have extended previous static rs-fcMRI studies to a dynamic study by exploring whether healthy siblings share aberrant dynamic FC patterns with schizophrenic patients, which may imply a potential risk for siblings to develop schizophrenia...
August 3, 2016: Neuroreport
R Hindriks, M H Adhikari, Y Murayama, M Ganzetti, D Mantini, N K Logothetis, G Deco
No abstract text is available yet for this article.
May 15, 2016: NeuroImage
Murat Demirtaş, Cristian Tornador, Carles Falcón, Marina López-Solà, Rosa Hernández-Ribas, Jesús Pujol, José M Menchón, Petra Ritter, Narcis Cardoner, Carles Soriano-Mas, Gustavo Deco
Resting-state fMRI (RS-fMRI) has become a useful tool to investigate the connectivity structure of mental health disorders. In the case of major depressive disorder (MDD), recent studies regarding the RS-fMRI have found abnormal connectivity in several regions of the brain, particularly in the default mode network (DMN). Thus, the relevance of the DMN to self-referential thoughts and ruminations has made the use of the resting-state approach particularly important for MDD. The majority of such research has relied on the grand averaged functional connectivity measures based on the temporal correlations between the BOLD time series of various brain regions...
August 2016: Human Brain Mapping
Armin Iraji, Vince D Calhoun, Natalie M Wiseman, Esmaeil Davoodi-Bojd, Mohammad R N Avanaki, E Mark Haacke, Zhifeng Kou
Spontaneous fluctuations of resting state functional MRI (rsfMRI) have been widely used to understand the macro-connectome of the human brain. However, these fluctuations are not synchronized among subjects, which leads to limitations and makes utilization of first-level model-based methods challenging. Considering this limitation of rsfMRI data in the time domain, we propose to transfer the spatiotemporal information of the rsfMRI data to another domain, the connectivity domain, in which each value represents the same effect across subjects...
July 1, 2016: NeuroImage
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