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https://www.readbyqxmd.com/read/28933012/erratum-to-the-callosal-relay-model-of-interhemispheric-communication-new-evidence-from-effective-connectivity-analysis
#1
Saskia Steinmann, Jan Meier, Guido Nolte, Andreas K Engel, Gregor Leicht, Christoph Mulert
No abstract text is available yet for this article.
September 20, 2017: Brain Topography
https://www.readbyqxmd.com/read/28928708/neural-patterns-of-reorganization-after-intensive-robot-assisted-virtual-reality-therapy-and-repetitive-task-practice-in-patients-with-chronic-stroke
#2
Soha Saleh, Gerard Fluet, Qinyin Qiu, Alma Merians, Sergei V Adamovich, Eugene Tunik
Several approaches to rehabilitation of the hand following a stroke have emerged over the last two decades. These treatments, including repetitive task practice (RTP), robotically assisted rehabilitation and virtual rehabilitation activities, produce improvements in hand function but have yet to reinstate function to pre-stroke levels-which likely depends on developing the therapies to impact cortical reorganization in a manner that favors or supports recovery. Understanding cortical reorganization that underlies the above interventions is therefore critical to inform how such therapies can be utilized and improved and is the focus of the current investigation...
2017: Frontiers in Neurology
https://www.readbyqxmd.com/read/28921863/gender-differences-in-brain-networks-during-verbal-sternberg-tasks-a-simultaneous-near-infrared-spectroscopy-and-electro-encephalography-study
#3
Chenyang Gao, Jinyan Sun, Xiaoquan Yang, Hui Gong
Gender differences in psychological processes have been of great interest in a variety of fields including verbal fluency, emotion processing, and working memory. Previous studies suggested that women outperform men in verbal working memory (VWM). However, the inherent mechanisms are still unclear. To obtain a deeper insight into the gender differences in brain networks in VWM, this study used near-infrared spectroscopy (NIRS) and electro-encephalography (EEG) simultaneously to investigate gender-related brain networks during verbal Sternberg tasks...
September 17, 2017: Journal of Biophotonics
https://www.readbyqxmd.com/read/28914524/templated-and-catalytic-fabrication-of-n-doped-hierarchical-porous-carbon-carbon-nanotubes-hybrids-as-host-for-lithium-sulfur-batteries
#4
Junjie Cai, Chun Wu, Shaoran Yang, Ying Zhu, Pei Kang Shen, Kaili Zhang
Nitrogen-doped hierarchical porous carbon and carbon nanotube hybrids (N-HPC-CNTs) are fabricated by simple pyrolysis of the N-rich raw material melamine-formaldehyde (MF) resin in the presence of nano-CaCO3 and bimetallic combination of Fe-Co catalyst. During carbonization, nano-CaCO3 acts as template for creating a hierarchical porous carbon and the N atoms originated from MF resin are in-situ doped into the carbon matrix simultaneously. Meanwhile, volatile gases generated by the thermal decomposition of MF resin could serve as carbon and nitrogen sources to grow nitrogen doped CNTs on HPC...
September 15, 2017: ACS Applied Materials & Interfaces
https://www.readbyqxmd.com/read/28881072/self-efficacy-modulates-the-neural-correlates-of-craving-in-male-smokers-and-ex-smokers-an-fmri-study
#5
Miki Ono, Takanori Kochiyama, Junya Fujino, Takashi Sozu, Ryosaku Kawada, Naoto Yokoyama, Genichi Sugihara, Toshiya Murai, Hidehiko Takahashi
The regulation of cue-induced craving for cigarettes is a key factor in smoking cessation. Outcomes of smoking cessation have been linked to self-efficacy, faith in one's own ability, in smokers. However, no study has examined the neural basis of self-efficacy during the control of craving. We examined whether self-efficacy can affect the neural response to smoking cues in smokers and ex-smokers using functional magnetic resonance imaging. During scanning, participants were instructed (1) to view smoking-related images passively, (2) to view the smoking-related images with a strategy focused on self-efficacy to control cue-induced craving or (3) to view neutral images...
September 7, 2017: Addiction Biology
https://www.readbyqxmd.com/read/28861336/a-whole-brain-computational-modeling-approach-to-explain-the-alterations-in-resting-state-functional-connectivity-during-progression-of-alzheimer-s-disease
#6
Murat Demirtaş, Carles Falcon, Alan Tucholka, Juan Domingo Gispert, José Luis Molinuevo, Gustavo Deco
Alzheimer's disease (AD) is the most common dementia with dramatic consequences. The research in structural and functional neuroimaging showed altered brain connectivity in AD. In this study, we investigated the whole-brain resting state functional connectivity (FC) of the subjects with preclinical Alzheimer's disease (PAD), mild cognitive impairment due to AD (MCI) and mild dementia due to Alzheimer's disease (AD), the impact of APOE4 carriership, as well as in relation to variations in core AD CSF biomarkers...
2017: NeuroImage: Clinical
https://www.readbyqxmd.com/read/28852979/estimation-of-effective-brain-connectivity-with-dual-kalman-filter-and-eeg-source-localization-methods
#7
Mehdi Rajabioun, Ali Motie Nasrabadi, Mohammad Bagher Shamsollahi
Effective connectivity is one of the most important considerations in brain functional mapping via EEG. It demonstrates the effects of a particular active brain region on others. In this paper, a new method is proposed which is based on dual Kalman filter. In this method, firstly by using a brain active localization method (standardized low resolution brain electromagnetic tomography) and applying it to EEG signal, active regions are extracted, and appropriate time model (multivariate autoregressive model) is fitted to extracted brain active sources for evaluating the activity and time dependence between sources...
August 29, 2017: Australasian Physical & Engineering Sciences in Medicine
https://www.readbyqxmd.com/read/28852402/short-term-observations-of-the-regenerative-potential-of-injured-proximal-sensory-nerves-crossed-with-distal-motor-nerves
#8
Xiu-Xiu Zhang, Yu-Hui Kou, Xiao-Feng Yin, Bao-Guo Jiang, Pei-Xun Zhang
Motor nerves and sensory nerves conduct signals in different directions and function in different ways. In the surgical treatment of peripheral nerve injuries, the best prognosis is obtained by keeping the motor and sensory nerves separated and repairing the nerves using the suture method. However, the clinical consequences of connections between sensory and motor nerves currently remain unknown. In this study, we analyzed the anatomical structure of the rat femoral nerve, and observed the motor and sensory branches of the femoral nerve in the quadriceps femoris...
July 2017: Neural Regeneration Research
https://www.readbyqxmd.com/read/28838469/the-unpredictive-brain-under-threat-a-neurocomputational-account-of-anxious-hypervigilance
#9
Brian R Cornwell, Marta I Garrido, Cassie Overstreet, Daniel S Pine, Christian Grillon
BACKGROUND: Anxious hypervigilance is marked by sensitized sensory-perceptual processes and attentional biases to potential danger cues in the environment. How this is realized at the neurocomputational level is unknown but could clarify the brain mechanisms disrupted in psychiatric conditions such as posttraumatic stress disorder. Predictive coding, instantiated by dynamic causal models, provides a promising framework to ground these state-related changes in the dynamic interactions of reciprocally connected brain areas...
September 15, 2017: Biological Psychiatry
https://www.readbyqxmd.com/read/28836726/dynamic-causal-modeling-in-ptsd-and-its-dissociative-subtype-bottom-up-versus-top-down-processing-within-fear-and-emotion-regulation-circuitry
#10
Andrew A Nicholson, Karl J Friston, Peter Zeidman, Sherain Harricharan, Margaret C McKinnon, Maria Densmore, Richard W J Neufeld, Jean Théberge, Frank Corrigan, Rakesh Jetly, David Spiegel, Ruth A Lanius
OBJECTIVE: Posttraumatic stress disorder (PTSD) is associated with decreased top-down emotion modulation from medial prefrontal cortex (mPFC) regions, a pathophysiology accompanied by hyperarousal and hyperactivation of the amygdala. By contrast, PTSD patients with the dissociative subtype (PTSD + DS) often exhibit increased mPFC top-down modulation and decreased amygdala activation associated with emotional detachment and hypoarousal. Crucially, PTSD and PTSD + DS display distinct functional connectivity within the PFC, amygdala complexes, and the periaqueductal gray (PAG), a region related to defensive responses/emotional coping...
August 24, 2017: Human Brain Mapping
https://www.readbyqxmd.com/read/28833746/a-tug-of-war-antagonistic-effective-connectivity-patterns-over-the-motor-cortex-and-the-severity-of-motor-symptoms-in-gilles-de-la-tourette-syndrome
#11
Laura Zapparoli, Marco Tettamanti, Mauro Porta, Alberto Zerbi, Domenico Servello, Giuseppe Banfi, Eraldo Paulesu
We tested the hypothesis that Gilles de la Tourette syndrome (GTS) is characterized by perturbed connectivity within cortico-subcortical motor networks. To this end, we performed a dynamic causal modelling (DCM) analysis of fMRI data collected during a finger opposition task in 24 normal controls and 24 GTS patients. The DCM analysis allowed us to assess whether any GTS-specific patterns of brain activity were related to intrinsic and/or to task-dependent connectivity. While no abnormalities were found for task-dependent connectivity, intrinsic connectivity was abnormally increased in the premotor network, with stronger connections from the supplementary motor area (SMA), from the dorsolateral premotor cortex and from the putamen to the right superior frontal gyrus, an area where GTS showed over-activation in a previous univariate analysis...
August 22, 2017: European Journal of Neuroscience
https://www.readbyqxmd.com/read/28828228/the-impact-of-hemodynamic-variability-and-signal-mixing-on-the-identifiability-of-effective-connectivity-structures-in-bold-fmri
#12
Natalia Z Bielczyk, Alberto Llera, Jan K Buitelaar, Jeffrey C Glennon, Christian F Beckmann
PURPOSE: Multiple computational studies have demonstrated that essentially all current analytical approaches to determine effective connectivity perform poorly when applied to synthetic functional Magnetic Resonance Imaging (fMRI) datasets. In this study, we take a theoretical approach to investigate the potential factors facilitating and hindering effective connectivity research in fMRI. MATERIALS AND METHODS: In this work, we perform a simulation study with use of Dynamic Causal Modeling generative model in order to gain new insights on the influence of factors such as the slow hemodynamic response, mixed signals in the network and short time series, on the effective connectivity estimation in fMRI studies...
August 2017: Brain and Behavior
https://www.readbyqxmd.com/read/28809668/tractography-based-score-for-learning-effective-connectivity-from-multimodal-imaging-data-using-dynamic-bayesian-networks
#13
Shilpa Dang, Santanu Chaudhury, Brejesh Lall, Prasun K Roy
OBJECTIVE: Effective connectivity (EC) is the methodology for determining functional-integration among the functionally-active segregated regions of the brain. By definition [1] EC is "the causal influence exerted by one neuronal group on another" which is constrained by anatomical connectivity (AC) (axonal connections). AC is necessary for EC but does not fully determine it, because synaptic communication occurs dynamically in a context-dependent fashion. Although there is a vast emerging evidence of structure-function relationship using multimodal imaging studies, till date only a few studies have done joint modelling of the two modalities: functional MRI (fMRI) and Diffusion Tensor Imaging (DTI)...
August 10, 2017: IEEE Transactions on Bio-medical Engineering
https://www.readbyqxmd.com/read/28803269/the-callosal-relay-model-of-interhemispheric-communication-new-evidence-from-effective-connectivity-analysis
#14
Saskia Steinmann, Jan Meier, Guido Nolte, Andreas K Engel, Gregor Leicht, Christoph Mulert
Interhemispheric auditory connectivity via the corpus callosum has been demonstrated to be important for normal speech processing. According to the callosal relay model, directed information flow from the right to the left auditory cortex has been suggested, but this has not yet been proven. For this purpose, 33 healthy participants were investigated with 64-channel EEG while performing the dichotic listening task in which two different consonant-vowel syllables were presented simultaneously to the left (LE) and right ear (RE)...
August 12, 2017: Brain Topography
https://www.readbyqxmd.com/read/28800340/reducing-the-rate-of-misdiagnosis-in%C3%A2-patients-with-chronic-disorders-of%C3%A2-consciousness-is-there-a-place-for-audiovisual-stimulation
#15
Antonino Naro, Antonino Leo, Rocco Bruno, Antonino Cannavò, Antonio Buda, Alfredo Manuli, Alessia Bramanti, Placido Bramanti, Rocco Salvatore Calabrò
BACKGROUND: The patients with chronic Disorders of Consciousness (DoC) mostly present with extremely challenging differential diagnosis. The advanced analysis of electroencephalographic (EEG) signals induced by brain stimulation paradigms may provide an appropriate approach to differentiate patients with DoC, besides the clinical assessment. OBJECTIVE: This study was performed with an objective of identifying residual brain network perturbations following an innovative, non-invasive audiovisual stimulation protocol, which could be related to behavioral responsiveness in patients with DoC...
August 11, 2017: Restorative Neurology and Neuroscience
https://www.readbyqxmd.com/read/28795112/real-time-fmri-data-for-testing-opennft-functionality
#16
Yury Koush, John Ashburner, Evgeny Prilepin, Ronald Sladky, Peter Zeidman, Sergei Bibikov, Frank Scharnowski, Artem Nikonorov, Dimitri Van De Ville
Here, we briefly describe the real-time fMRI data that is provided for testing the functionality of the open-source Python/Matlab framework for neurofeedback, termed Open NeuroFeedback Training (OpenNFT, Koush et al. [1]). The data set contains real-time fMRI runs from three anonymized participants (i.e., one neurofeedback run per participant), their structural scans and pre-selected ROIs/masks/weights. The data allows for simulating the neurofeedback experiment without an MR scanner, exploring the software functionality, and measuring data processing times on the local hardware...
October 2017: Data in Brief
https://www.readbyqxmd.com/read/28791721/cortical-control-of-object-specific-grasp-relies-on-adjustments-of-both-activity-and-effective-connectivity-a-common-marmoset-study
#17
Banty Tia, Mitsuaki Takemi, Akito Kosugi, Elisa Castagnola, Alberto Ansaldo, Takafumi Nakamura, Davide Ricci, Junichi Ushiba, Luciano Fadiga, Atsushi Iriki
The cortical mechanisms of grasping have been extensively studied in macaques and humans. Here, we investigated whether common marmosets could rely on similar mechanisms despite striking differences in manual dexterity. Two common marmosets were trained to grasp-and-pull three objects eliciting different hand configurations: whole-hand, finger and scissor grips. The animals were then chronically implanted with 64-channel electrocorticogram arrays positioned over the left premotor, primary motor and somatosensory cortex...
August 9, 2017: Journal of Physiology
https://www.readbyqxmd.com/read/28782683/unidirectional-brain-to-muscle-connectivity-reveals-motor-cortex-control-of-leg-muscles-during-stereotyped-walking
#18
Fiorenzo Artoni, Chiara Fanciullacci, Federica Bertolucci, Alessandro Panarese, Scott Makeig, Silvestro Micera, Carmelo Chisari
In lower mammals, locomotion seems to be mainly regulated by subcortical and spinal networks. On the contrary, recent evidence suggests that in humans the motor cortex is also significantly engaged during complex locomotion tasks. However, a detailed understanding of cortical contribution to locomotion is still lacking especially during stereotyped activities. Here, we show that cortical motor areas finely control leg muscle activation during treadmill stereotyped walking. Using a novel technique based on a combination of Reliable Independent Component Analysis, source localization and effective connectivity, and by combining electroencephalographic (EEG) and electromyographic (EMG) recordings in able-bodied adults we were able to examine for the first time cortical activation patterns and cortico-muscular connectivity including information flow direction...
August 4, 2017: NeuroImage
https://www.readbyqxmd.com/read/28782678/resting-state-networks-in-empirical-and-simulated-dynamic-functional-connectivity
#19
Katharina Glomb, Adrián Ponce-Alvarez, Matthieu Gilson, Petra Ritter, Gustavo Deco
It is well-established that patterns of functional connectivity (FC) - measures of correlated activity between pairs of voxels or regions observed in the human brain using neuroimaging - are robustly expressed in spontaneous activity during rest. These patterns are not static, but exhibit complex spatio-temporal dynamics. Over the last years, a multitude of methods have been proposed to reveal these dynamics on the level of the whole brain. One finding is that the brain transitions through different FC configurations over time, and substantial effort has been put into characterizing these configurations...
August 3, 2017: NeuroImage
https://www.readbyqxmd.com/read/28774647/discrimination-of-a-medial-functional-module-within-the-temporal-lobe-using-an-effective-connectivity-model-a-ccep-study
#20
Julien Krieg, Laurent Koessler, Jacques Jonas, Sophie Colnat-Coulbois, Jean-Pierre Vignal, Christian G Bénar, Louis G Maillard
The temporal lobe is classically divided in two functional systems: the ventral visual pathway and the medial temporal memory system. However, their functional separation has been challenged by studies suggesting that the medial temporal lobe could be best understood as an extension of the hierarchically organized ventral visual pathway. Our purpose was to investigate (i) whether cerebral regions within the temporal lobe could be grouped into distinct functional assemblies, and (ii) which regions were central within these functional assemblies...
July 31, 2017: NeuroImage
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