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Brain Connectivity

Casey Paquola, Maxwell Bennett, Jim Lagopoulos
Structural covariance networks (SCNs) may offer unique insights into the developmental impact of childhood maltreatment because they are thought to reflect coordinated maturation of distinct grey matter regions. T1-weighted magnetic resonance images were acquired from 121 young people with emerging mental illness. Diffusion weighted and resting state functional imaging was also acquired from a random subset of the participants (n=62). Ten study-specific SCNs were identified using a whole brain grey matter independent component analysis...
May 15, 2018: Brain Connectivity
Ranjit Thuraisingham
Statistical parameters that measure the strength, integration and segregation of a multi channel electroencephalograph (EEG) network are evaluated using a similarity measure based on mutual information (MI) between the measured channel data. Compared to the unsigned linear correlation coefficient, MI is more robust to volume conduction and is applicable to nonlinear data. The statistical parameters that are estimated are: node strength, average path length and clustering coefficient. These parameters provide valuable insights into the brain network of the subject...
May 14, 2018: Brain Connectivity
Didac Macia, Jesus Pujol, Laura Blanco-Hinojo, Gerard Martínez-Vilavella, Rocío Martín-Santos, Joan Deus
There is ample evidence from basic research in neuroscience of the importance of local cortico-cortical networks. Millimetric resolution is achievable with current functional MRI (fMRI) scanners and sequences, and consequently a number of "local" activity similarity measures have been defined to describe patterns of segregation and integration at this spatial scale. We have introduced the use of Iso-Distant local Average Correlation (IDAC), easily defined as the average fMRI temporal correlation of a given voxel with other voxels placed at increasingly separated iso-distant intervals, to characterize the curve of local fMRI signal similarities...
April 24, 2018: Brain Connectivity
Michael T Jurkiewicz, Adrian P Crawley, David J Mikulis
Numerous studies have identified the default mode network (DMN) within the brain of healthy individuals, which has been attributed to the ongoing mental activity of the brain during the wakeful resting-state. While engaged during specific resting-state fMRI paradigms, it remains unclear as to whether traditional block-design simple movement fMRI experiments significantly influence the default mode network or other areas. Using blood-oxygen level dependent (BOLD) fMRI we characterized the pattern of functional connectivity in healthy subjects during a resting-state paradigm and compared this to the same resting-state analysis performed on motor task data residual time courses after regressing out the task paradigm...
April 18, 2018: Brain Connectivity
Seul Lee, Jonathan R Polimeni, Collin M Price, Brian L Edlow, Jennifer A McNab
Resting-state functional magnetic resonance imaging (RS-FMRI) has been widely used to map brain functional connectivity, but it is unclear how to probe connectivity within and around lesions. Here we characterize RS-FMRI signal time-course properties and evaluate different seed placements within and around hemorrhagic traumatic axonal injury lesions. RS-FMRI was performed on a 7 Tesla scanner in a patient who recovered consciousness after traumatic coma and in three healthy controls. Eleven lesions in the patient were characterized in terms of: 1) temporal signal-to-noise ratio (tSNR); 2) physiological noise, through comparison of noise regressors derived from the white matter (WM), cerebrospinal fluid (CSF) and gray matter (GM); and 3) seed-based functional connectivity...
April 18, 2018: Brain Connectivity
Marco Fuscà, Philipp Ruhnau, Toralf Neuling, Nathan Weisz
Transcranial alternating current stimulation (tACS) has been proposed as a tool to draw causal inferences on the role of oscillatory activity in cognitive functioning and has the potential to induce long-term changes in cerebral networks. However, effectiveness of tACS underlies high variability and dependencies, which, as previous modeling works have suggested, may be mediated by local and network-level brain states. We used magnetoencephalography to record brain activity from 17 healthy participants at rest as they kept their eyes open (EO) or eyes closed (EC) while being stimulated with sham, weak, or strong alpha-tACS using a montage commonly assumed to target occipital areas...
May 2018: Brain Connectivity
Jessika Nystedt, Peter Mannfolk, Andreas Jönsen, Anders Bengtsson, Petra Nilsson, Pia C Sundgren, Tor O Strandberg
To investigate resting-state functional connectivity of lupus patients and associated subgroups according to the ACR NPSLE case definitions (ACR ad hoc). In addition, we investigated whether or not the observed alterations correlated with disease duration, the systemic lupus erythematosus (SLE)-Disease Activity Index-2000 (SLEDAI-2k), and Systemic Lupus International Collaborating Clinical/ACR organ damage index (SDI)-scores. Anatomical 3T magnetic resonance imaging (MRI) and resting-state functional MRI were performed in 61 female lupus patients (mean age = 37...
April 5, 2018: Brain Connectivity
Deniz Vatansever, Anne Manktelow, Barbara J Sahakian, David K Menon, Emmanuel A Stamatakis
The default mode network (DMN) is typically associated with off-task internal mentation, or with goal-oriented tasks that require self-referential processing such as autobiographical planning. However, recent reports suggest a broader involvement of the DMN in higher cognition. In line with this view, we report global connectivity changes that are centered on the main DMN hubs of precuneus and posterior cingulate cortex during a functional magnetic resonance imaging-based visuospatial version of the Tower of London planning task...
April 5, 2018: Brain Connectivity
Anna M Wirth, Sebastian M Frank, Mark W Greenlee, Anton L Beer
The parieto-insular vestibular cortex (PIVC) and the posterior insular cortex (PIC) are key regions of the cortical vestibular network, both located in the mid-posterior section of the lateral sulcus. Little is known about the structural connectivity pattern of these areas. We employed probabilistic fiber tracking based on diffusion-weighted magnetic resonance imaging (MRI) and compared the ipsilateral connectivity of PIVC and PIC. Seed areas for the tracking algorithm were identified in each brain by functional MRI activity during caloric and visual motion stimulation, respectively...
March 23, 2018: Brain Connectivity
Priya Santhanam, E Susan Duncan, Steven L Small
Cortical reorganization after stroke is thought to underlie functional improvement. Patterns of reorganization may differ depending on the amount of time since the stroke or the degree of improvement. We investigated these issues in a study of brain connectivity changes with aphasia therapy. Twelve individuals with chronic aphasia participated in a 6-week trial of imitation-based speech therapy. We assessed improvement on a repetition test and analyzed effective connectivity during functional magnetic resonance imaging of a speech observation task before and after therapy...
March 23, 2018: Brain Connectivity
Shiyang Chen, Xiaoping P Hu
Individual identification based on brain function has gained traction in literature. Investigating individual differences in brain function can provide additional insights into the brain. In this work, we introduce a recurrent neural network based model for identifying individuals based on only a short segment of resting state functional MRI data. In addition, we demonstrate how the global signal and differences in atlases affect the individual identifiability. Furthermore, we investigate neural network features that exhibit the uniqueness of each individual...
March 20, 2018: Brain Connectivity
John J Sidtis, Diana Van Lancker Sidtis, Vijay Dhawan, David Eidelberg
Language has been modeled as a rule governed behavior for generating an unlimited number of novel utterances using phonological, syntactic, and lexical processes. This view of language as essentially propositional is expanding as a contributory role of formulaic expressions (e.g., you know, have a nice day, how are you?) is increasingly recognized. The basic features of the functional anatomy of this language system have been described by studies of brain damage: left lateralization for propositional language and greater right lateralization and basal ganglia involvement for formulaic expressions...
March 19, 2018: Brain Connectivity
Yunan Zhu, Ivor Cribben
Sparse graphical models are frequently used to explore both static and dynamic functional brain networks from neuroimaging data. However, the practical performance of the models has not been studied in detail for brain networks. In this work, we have two objectives. First, we compare several sparse graphical model estimation procedures and several selection criteria under various experimental settings, such as different dimensions, sample sizes, types of data, and sparsity levels of the true model structures...
March 13, 2018: Brain Connectivity
Jared Rowland, Jennifer Stapleton-Kotloski, Dorothy Dobbins, Emily Rogers, Dwayne Godwin, Katherine Taber
Cross-sectional and longitudinal studies in active duty and veteran cohorts have both demonstrated that deployment-acquired traumatic brain injury (TBI) is an independent risk factor for developing posttraumatic stress disorder (PTSD), beyond confounds such as combat exposure, physical injury, pre-deployment TBI, and pre-deployment psychiatric symptoms. The current study investigated how resting-state brain networks differ between individuals who go on to develop PTSD and those who do not following deployment-acquired TBI...
March 8, 2018: Brain Connectivity
Tien-Wen Lee, Shao-Wei Xue
Multimodal neuroimaging research has become increasingly popular, and structure-function correspondence is tacitly assumed. Researchers have not yet adequately assessed whether the functional connectivity (FC) and structural connectivity (SC) of large-scale cortical networks are in agreement. Structural magnetic resonance imaging (sMRI), resting-state functional MRI (rfMRI), and diffusion-weighted imaging (DWI) data sets from 36 healthy subjects (age 27.4) were selected from a Rockland sample (Enhanced Nathan Kline Institute)...
March 2, 2018: Brain Connectivity
Jacob Billings, Shella Keilholz
Global signal regression is a controversial processing step for resting-state functional magnetic resonance imaging, partly because the source of the global blood oxygen level-dependent (BOLD) signal remains unclear. On the one hand, nuisance factors such as motion can readily introduce coherent BOLD changes across the whole brain. On the other hand, the global signal has been linked to neural activity and vigilance levels, suggesting that it contains important neurophysiological information and should not be discarded...
April 2018: Brain Connectivity
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No abstract text is available yet for this article.
March 2018: Brain Connectivity
Kaundinya Gopinath, Venkatagiri Krishnamurthy, Simon Lacey, K Sathian
In a recent study Eklund et al. have shown that cluster-wise family-wise error (FWE) rate-corrected inferences made in parametric statistical method-based functional magnetic resonance imaging (fMRI) studies over the past couple of decades may have been invalid, particularly for cluster defining thresholds less stringent than p < 0.001; principally because the spatial autocorrelation functions (sACFs) of fMRI data had been modeled incorrectly to follow a Gaussian form, whereas empirical data suggest otherwise...
February 2018: Brain Connectivity
Sheeba Arnold Anteraper, Xavier Guell, Susan Whitfield-Gabrieli, Christina Triantafyllou, Aaron T Mattfeld, John D Gabrieli, Maiya R Geddes
The subthalamic nucleus (STN) is a small structure situated deep in the midbrain that exhibits wide-ranging functionality. In addition to its role in motor control, the STN is considered a hub for synchronizing aspects of emotion and cognition including attention, inhibitory control, motivation, and working memory. Evidence from neuroanatomical tracer studies suggests that the medial, ventromedial, and dorsolateral parts of the STN correspond to limbic, associative, and motor subdivisions, respectively. Although the extent of STN functional anatomical overlap remains unclear, blood oxygenation level dependent imaging of the STN may provide complementary information about the diverse functions of this structure...
February 2018: Brain Connectivity
Zack Y Shan, Kevin Finegan, Sandeep Bhuta, Timothy Ireland, Donald R Staines, Sonya M Marshall-Gradisnik, Leighton R Barnden
The chronic fatigue syndrome (CFS)/myalgic encephalomyelitis is a debilitating disease with unknown pathophysiology and no diagnostic test. This study investigated the default mode network (DMN) to understand the pathophysiology of CFS and to identify potential biomarkers. Using functional MRI (fMRI) collected from 72 subjects (45 CFS and 27 controls) with a temporal resolution of 0.798 sec, we evaluated the DMN using static functional connectivity (FC), dynamic functional connectivity (DFC) and DFC complexity, blood oxygenation level dependent (BOLD) activation maps, and complexity of activity...
February 2018: Brain Connectivity
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