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https://www.readbyqxmd.com/read/29161362/the-hierarchical-organization-of-the-default-dorsal-attention-and-salience-networks-in-adolescents-and-young-adults
#1
Yuan Zhou, Karl J Friston, Peter Zeidman, Jie Chen, Shu Li, Adeel Razi
An important characteristic of spontaneous brain activity is the anticorrelation between the core default network (cDN) and the dorsal attention network (DAN) and the salience network (SN). This anticorrelation may constitute a key aspect of functional anatomy and is implicated in several brain disorders. We used dynamic causal modeling to assess the hypothesis that a causal hierarchy underlies this anticorrelation structure, using resting-state fMRI of healthy adolescent and young adults (N = 404). Our analysis revealed an asymmetric effective connectivity, such that the regions in the SN and DAN exerted an inhibitory influence on the cDN regions; whereas the cDN exerted an excitatory influence on the SN and DAN regions...
November 17, 2017: Cerebral Cortex
https://www.readbyqxmd.com/read/29158879/changes-in-effective-connectivity-network-patterns-in-drug-abusers-treated-with-different-methods
#2
Arash Zare Sadeghi, Amir Homayoun Jafari, Mohammad Ali Oghabian, Hamid Reza Salighehrad, Seyed Amir Hossein Batouli, Samira Raminfard, Hamed Ekhtiari
Introduction: Various treatment methods for drug abusers will result in different success rates. This is partly due to different neural assumptions and partly due to various rate of relapse in abusers because of different circumstances. Investigating the brain activation networks of treated subjects can reveal the hidden mechanisms of the therapeutic methods. Methods: We studied three groups of subjects: heroin abusers treated with abstinent based therapy (ABT) method, heroin abusers treated with Methadone Maintenance Therapy (MMT) method, and a control group...
July 2017: Basic and Clinical Neuroscience
https://www.readbyqxmd.com/read/29158202/dynamic-effective-connectivity-in-resting-state-fmri
#3
REVIEW
Hae-Jeong Park, Karl Friston, Chongwon Pae, Bumhee Park, Adeel Razi
Context-sensitive and activity-dependent fluctuations in connectivity underlie functional integration in the brain and have been studied widely in terms of synaptic plasticity, learning and condition-specific (e.g., attentional) modulations of synaptic efficacy. This dynamic aspect of brain connectivity has recently attracted a lot of attention in the resting state fMRI community. To explain dynamic functional connectivity in terms of directed effective connectivity among brain regions, we introduce a novel method to identify dynamic effective connectivity using spectral dynamic causal modelling (spDCM)...
November 17, 2017: NeuroImage
https://www.readbyqxmd.com/read/29137413/abnormal-neural-activities-of-directional-brain-networks-in-patients-with-long-term-bilateral-hearing-loss
#4
Long-Chun Xu, Gang Zhang, Yue Zou, Min-Feng Zhang, Dong-Sheng Zhang, Hua Ma, Wen-Bo Zhao, Guang-Yu Zhang
The objective of the study is to provide some implications for rehabilitation of hearing impairment by investigating changes of neural activities of directional brain networks in patients with long-term bilateral hearing loss. Firstly, we implemented neuropsychological tests of 21 subjects (11 patients with long-term bilateral hearing loss, and 10 subjects with normal hearing), and these tests revealed significant differences between the deaf group and the controls. Then we constructed the individual specific virtual brain based on functional magnetic resonance data of participants by utilizing effective connectivity and multivariate regression methods...
October 13, 2017: Oncotarget
https://www.readbyqxmd.com/read/29136125/effective-connectivity-measured-using-optogenetically-evoked-hemodynamic-signals-exhibits-topography-distinct-from-resting-state-functional-connectivity-in-the-mouse
#5
Adam Q Bauer, Andrew W Kraft, Grant A Baxter, Patrick W Wright, Matthew D Reisman, Annie R Bice, Jasmine J Park, Michael R Bruchas, Abraham Z Snyder, Jin-Moo Lee, Joseph P Culver
Brain connectomics has expanded from histological assessment of axonal projection connectivity (APC) to encompass resting state functional connectivity (RS-FC). RS-FC analyses are efficient for whole-brain mapping, but attempts to explain aspects of RS-FC (e.g., interhemispheric RS-FC) based on APC have been only partially successful. Neuroimaging with hemoglobin alone lacks specificity for determining how activity in a population of cells contributes to RS-FC. Wide-field mapping of optogenetically defined connectivity could provide insights into the brain's structure-function relationship...
November 9, 2017: Cerebral Cortex
https://www.readbyqxmd.com/read/29128871/neural-substrate-of-unrelenting-negative-symptoms-in-schizophrenia-a-longitudinal-resting-state-fmri-study
#6
Mingli Li, Wei Deng, Tushar Das, Yinfei Li, Liansheng Zhao, Xiaohong Ma, Yingcheng Wang, Hua Yu, Xiaojing Li, Ya-Jing Meng, Qiang Wang, Lena Palaniyappan, Tao Li
Developing a mechanistic insight into the specific brain processes that underpin improvement in negative symptoms can help us design novel chemical and physical treatments against these unrelenting symptoms. The aim of the present study is to explore the longitudinal changes in the brain's regional functional efficiency that accompany improvement in negative symptoms seen in first-episode patients with schizophrenia when treated with antipsychotic for 1 year. Forty-seven first-episode patients with schizophrenia were scanned at a drug-naive baseline state and followed up for 1 year to identify negative symptom responders (Rn) and non-responders (NRn)...
November 11, 2017: European Archives of Psychiatry and Clinical Neuroscience
https://www.readbyqxmd.com/read/29128543/high-frequency-neurons-determine-effective-connectivity-in-neuronal-networks
#7
Aref Pariz, Zahra G Esfahani, Shervin S Parsi, Alireza Valizadeh, Santiago Canals, Claudio R Mirasso
The emergence of flexible information channels in brain networks is a fundamental question in neuroscience. Understanding the mechanisms of dynamic routing of information would have far-reaching implications in a number of disciplines ranging from biology and medicine to information technologies and engineering. In this work, we show that the presence of a node firing at a higher frequency in a network with local connections, leads to reliable transmission of signals and establishes a preferential direction of information flow...
November 8, 2017: NeuroImage
https://www.readbyqxmd.com/read/29123475/cerebello-cortical-differences-in-effective-connectivity-of-the-dominant-and-non-dominant-hand-during-a-visuomotor-paradigm-of-grip-force-control
#8
Eric Moulton, Cécile Galléa, Claire Kemlin, Romain Valabregue, Marc A Maier, Pavel Lindberg, Charlotte Rosso
Structural and functional differences are known to exist within the cortical sensorimotor networks with respect to the dominant vs. non-dominant hand. Similarly, the cerebellum, a key structure in the sensorimotor network with its cerebello-cortical connections, has been reported to respond differently when using the dominant vs. non-dominant hand. Several groups have already investigated causal interactions during diverse motor paradigms using effective connectivity but few have studied the larger visuomotor network, including key structures such as the parietal cortex and the cerebellum, with both hands...
2017: Frontiers in Human Neuroscience
https://www.readbyqxmd.com/read/29116660/increased-hippocampus-to-ventromedial-prefrontal-connectivity-during-the-construction-of-episodic-future-events
#9
Karen L Campbell, Kevin P Madore, Roland G Benoit, Preston P Thakral, Daniel L Schacter
Both the hippocampus and ventromedial prefrontal cortex (vmPFC) appear to be critical for episodic future simulation. Damage to either structure affects one's ability to remember the past and imagine the future, and both structures are commonly activated as part of a wider core network during future simulation. However, the precise role played by each of these structures and, indeed, the direction of information flow between them during episodic simulation, is still not well understood. In this study, we scanned participants using functional magnetic resonance imaging while they imagined future events in response to object cues...
November 8, 2017: Hippocampus
https://www.readbyqxmd.com/read/29111478/verbal-working-memory-and-functional-large-scale-networks-in-schizophrenia
#10
Maria R Dauvermann, Thomas Wj Moorhead, Andrew R Watson, Barbara Duff, Liana Romaniuk, Jeremy Hall, Neil Roberts, Graham L Lee, Zoë A Hughes, Nicholas J Brandon, Brandon Whitcher, Douglas Hr Blackwood, Andrew M McIntosh, Stephen M Lawrie
The aim of this study was to test whether bilinear and nonlinear effective connectivity (EC) measures of working memory fMRI data can differentiate between patients with schizophrenia (SZ) and healthy controls (HC). We applied bilinear and nonlinear Dynamic Causal Modeling (DCM) for the analysis of verbal working memory in 16 SZ and 21 HC. The connection strengths with nonlinear modulation between the dorsolateral prefrontal cortex (DLPFC) and the ventral tegmental area/substantia nigra (VTA/SN) were evaluated...
October 23, 2017: Psychiatry Research
https://www.readbyqxmd.com/read/29108734/altered-anterior-cingulate-cortex-to-hippocampus-effective-connectivity-in-response-to-drug-cues-in-men-with-cocaine-use-disorder
#11
Liangsuo Ma, Joel L Steinberg, Kathryn A Cunningham, James M Bjork, Scott D Lane, Joy M Schmitz, Thomas Burroughs, Ponnada A Narayana, Thomas R Kosten, Antoine Bechara, F Gerard Moeller
Drug-related attentional bias may have significant implications for the treatment of cocaine use disorder (CocUD). However, the neurobiology of attentional bias is not completely understood. This study employed dynamic causal modeling (DCM) to conduct an analysis of effective (directional) connectivity involved in drug-related attentional bias in treatment-seeking CocUD subjects. The DCM analysis was conducted based on functional magnetic resonance imaging (fMRI) data acquired from fifteen CocUD subjects while performing a cocaine-word Stroop task, during which blocks of Cocaine Words (CW) and Neutral Words (NW) alternated...
October 27, 2017: Psychiatry Research
https://www.readbyqxmd.com/read/29108300/different-patterns-of-age-related-central-olfactory-decline-in-men-and-women-as-quantified-by-olfactory-fmri
#12
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)...
October 3, 2017: Oncotarget
https://www.readbyqxmd.com/read/29103032/alterations-of-effective-connectivity-patterns-in-mild-cognitive-impairment-an-meg-study
#13
Carlos Gómez, Celia Juan-Cruz, Jesús Poza, Saúl J Ruiz-Gómez, Javier Gomez-Pilar, Pablo Núñez, María García, Alberto Fernández, Roberto Hornero
Neuroimaging techniques have demonstrated over the years their ability to characterize the brain abnormalities associated with different neurodegenerative diseases. Among all these techniques, magnetoencephalography (MEG) stands out by its high temporal resolution and noninvasiveness. The aim of the present study is to explore the coupling patterns of resting-state MEG activity in subjects with mild cognitive impairment (MCI). To achieve this goal, five minutes of spontaneous MEG activity were acquired with a 148-channel whole-head magnetometer from 18 MCI patients and 26 healthy controls...
October 30, 2017: Journal of Alzheimer's Disease: JAD
https://www.readbyqxmd.com/read/29101022/lsd-modulates-effective-connectivity-and-neural-adaptation-mechanisms-in-an-auditory-oddball-paradigm
#14
REVIEW
Christopher Timmermann, Meg J Spriggs, Mendel Kaelen, Robert Leech, David J Nutt, Rosalyn J Moran, Robin L Carhart-Harris, Suresh D Muthukumaraswamy
Under the predictive coding framework, perceptual learning and inference are dependent on the interaction between top-down predictions and bottom-up sensory signals both between and within regions in a network. However, how such feedback and feedforward connections are modulated in the state induced by lysergic acid diethylamide (LSD) is poorly understood. In this study, an auditory oddball paradigm was presented to healthy participants (16 males, 4 female) under LSD and placebo, and brain activity was recorded using magnetoencephalography (MEG)...
October 31, 2017: Neuropharmacology
https://www.readbyqxmd.com/read/29081745/changes-of-functional-and-directed-resting-state-connectivity-are-associated-with-neuronal-oscillations-apoe-genotype-and-amyloid-deposition-in-mild-cognitive-impairment
#15
Lars Michels, Muthuraman Muthuraman, Abdul R Anwar, Spyros Kollias, Sandra E Leh, Florian Riese, Paul G Unschuld, Michael Siniatchkin, Anton F Gietl, Christoph Hock
The assessment of effects associated with cognitive impairment using electroencephalography (EEG) power mapping allows the visualization of frequency-band specific local changes in oscillatory activity. In contrast, measures of coherence and dynamic source synchronization allow for the study of functional and effective connectivity, respectively. Yet, these measures have rarely been assessed in parallel in the context of mild cognitive impairment (MCI) and furthermore it has not been examined if they are related to risk factors of Alzheimer's disease (AD) such as amyloid deposition and apolipoprotein ε4 (ApoE) allele occurrence...
2017: Frontiers in Aging Neuroscience
https://www.readbyqxmd.com/read/29081422/neural-activation-patterns-and-connectivity-in-visual-attention-during-number-and-non-number-processing-an-erp-study-using-the-ishihara-pseudoisochromatic-plates
#16
Faraj Al-Marri, Faruque Reza, Tahamina Begum, Wan Hazabbah Wan Hitam, Goh Khean Jin, Jing Xiang
Visual cognitive function is important to build up executive function in daily life. Perception of visual Number form (e.g., Arabic digit) and numerosity (magnitude of the Number) is of interest to cognitive neuroscientists. Neural correlates and the functional measurement of Number representations are complex occurrences when their semantic categories are assimilated with other concepts of shape and colour. Colour perception can be processed further to modulate visual cognition. The Ishihara pseudoisochromatic plates are one of the best and most common screening tools for basic red-green colour vision testing...
October 25, 2017: Journal of Integrative Neuroscience
https://www.readbyqxmd.com/read/29062950/synthetic-biology-in-the-uk-an-outline-of-plans-and-progress
#17
REVIEW
L J Clarke, R I Kitney
Synthetic biology is capable of delivering new solutions to key challenges spanning the bioeconomy, both nationally and internationally. Recognising this significant potential and the associated need to facilitate its translation and commercialisation the UK government commissioned the production of a national Synthetic Biology Roadmap in 2011, and subsequently provided crucial support to assist its implementation. Critical infrastructural investments have been made, and important strides made towards the development of an effectively connected community of practitioners and interest groups...
December 2016: Synthetic and Systems Biotechnology
https://www.readbyqxmd.com/read/29060399/evaluation-of-different-cochlear-implants-in-unilateral-hearing-patients-during-word-listening-tasks-a-brain-connectivity-study
#18
Anton Giulio Maglione, Giulia Cartocci, Enrica Modica, Dario Rossi, Alfredo Colosimo, Gianluca Di Flumeri, Ambra Brizi, Isotta Venuti, Maria Zinfollino, Paolo Malerba, Nicola Quaranta, Fabio Babiloni
Advanced methodologies used for the biomedical signal interpretation allow using cerebral signals to assess important cognitive functions in humans. In the present study, as parameter of cerebral effort, has been employed the isolated effective coherence, in order to estimate the effective connectivity and network organization. The hypothesis was that the lower the number of inter-connections engaged, the lower the cerebral effort induced by the experimental condition. In the present research this index has been applied to test the reaction to the use of different cochlear implant processors (Freedom, CP810 and CP910 - Cochlear Ltd), with the aim to identify the most performing device during a word in noise recognition task...
July 2017: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/29058357/identifying-disease-foci-from-static-and-dynamic-effective-connectivity-networks-illustration-in-soldiers-with-trauma
#19
D Rangaprakash, Michael N Dretsch, Archana Venkataraman, Jeffrey S Katz, Thomas S Denney, Gopikrishna Deshpande
Brain connectivity studies report group differences in pairwise connection strengths. While informative, such results are difficult to interpret since our understanding of the brain relies on region-based properties, rather than on connection information. Given that large disruptions in the brain are often caused by a few pivotal sources, we propose a novel framework to identify the sources of functional disruption from effective connectivity networks. Our approach integrates static and time-varying effective connectivity modeling in a probabilistic framework, to identify aberrant foci and the corresponding aberrant connectomics network...
October 23, 2017: Human Brain Mapping
https://www.readbyqxmd.com/read/29052616/pregenual-anterior-cingulate-dysfunction-associated-with-depression-in-ocd-an-integrated-multimodal-fmri-1-h-mrs-study
#20
Reza Tadayonnejad, Rangaprakash Deshpande, Olusola Ajilore, Teena Moody, Francesca Morfini, Ronald Ly, Joseph O'Neill, Jamie D Feusner
Depression is a commonly-occurring symptom in obsessive-compulsive disorder (OCD), and is associated with worse functional impairment, poorer quality of life, and poorer treatment response. Understanding the underlying neurochemical and connectivity-based brain mechanisms of this important symptom domain in OCD is necessary for development of novel, more globally effective treatments. To investigate biopsychological mechanisms of comorbid depression in OCD, we examined effective connectivity and neurochemical signatures in the pregenual anterior cingulate cortex (pACC), a structure known to be involved in both OCD and depression...
October 20, 2017: Neuropsychopharmacology: Official Publication of the American College of Neuropsychopharmacology
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