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Effects of lesions on synchrony and metastability in cortical networks

František Váša, Murray Shanahan, Peter J. Hellyer, Gregory Scott, Joana Cabral, Robert Leech
2015 NeuroImage  
The removal of nodes with high eigenvector centrality leads to decreases in global synchrony and increases in global metastability, as does the removal of hub nodes joining topologically segregated network  ...  By removing individual nodes and all of their connections from the model, we study the effect of lesions on both global and local dynamics.  ...  Acknowledgments We would like to thank Patric Hagmann for providing the structural and functional connectomes used in this study.  ... 
doi:10.1016/j.neuroimage.2015.05.042 pmid:26049146 fatcat:ynokmrppxnegldrtbtyfi6bcxm

Metastable neural dynamics in Alzheimer's disease are disrupted by lesions to the structural connectome

Thomas H. Alderson, Arun L.W. Bokde, J.A. Scott Kelso, Liam Maguire, Damien Coyle
2018 NeuroImage  
We estimate the metastability of fMRI BOLD signal in subjects from across the AD spectrum and in healthy controls and demonstrate the dissociable effects of structural disconnection on synchrony versus  ...  Accordingly, we use a joint empirical and computational approach to reveal how behaviourally relevant changes in neural metastability are contingent on the structural integrity of the anatomical connectome  ...  ADNI is funded by the National Institute on Aging, the National Institute of Biomedical Imaging and Bioengineering, and through generous contributions from the following:  ... 
doi:10.1016/j.neuroimage.2018.08.033 pmid:30130642 pmcid:PMC6374703 fatcat:htbcxdskcveqxmpeiw7sprp7b4

Cognitive Flexibility through Metastable Neural Dynamics Is Disrupted by Damage to the Structural Connectome

P. J. Hellyer, G. Scott, M. Shanahan, D. J. Sharp, R. Leech
2015 Journal of Neuroscience  
Our findings suggest how metastable dynamics are important for normal brain function and contingent on the structure of the human connectome.  ...  reduced cognitive flexibility, that may be a result of disrupted metastable dynamics.  ...  Thirty-two patients in the TBI group were found to have focal gray matter lesions, suggestive of cortical contusions, on T1-weighted structural imaging.  ... 
doi:10.1523/jneurosci.4648-14.2015 pmid:26085630 pmcid:PMC4469735 fatcat:2akaw3gh4zf6jntilzkxzi6by4

Thalamic bursts modulate cortical synchrony locally to switch between states of global functional connectivity in a cognitive task [article]

Oscar Portoles, Manuel Blesa, Marieke van Vugt, Ming Cao, Jelmer Borst
2021 bioRxiv   pre-print
These findings confirm that cognitive stages are defined by distinct states of cortical synchrony and explains the network-level mechanisms necessary for reaching stage-dependent synchrony states.  ...  The model suggests that the observed synchrony is caused by thalamocortical bursts at the onset of each stage, targeted at cortical synapses and interacting with the structural anatomical connectivity.  ...  Acknowledgments The work of Cao was supported in part by the European Research Council (ERC-CoG-771687).  ... 
doi:10.1101/2021.09.01.458489 fatcat:ei7qx45cwjhevawq5pvsb44cya

Thalamic bursts modulate cortical synchrony locally to switch between states of global functional connectivity in a cognitive task

Oscar Portoles, Manuel Blesa, Marieke van Vugt, Ming Cao, Jelmer P. Borst, Daniel Bush
2022 PLoS Computational Biology  
These findings confirm that cognitive stages are defined by distinct states of cortical synchrony and explains the network-level mechanisms necessary for reaching stage-dependent synchrony states.  ...  The model suggests that the observed synchrony is caused by thalamocortical bursts at the onset of each stage, targeted at cortical synapses and interacting with the structural anatomical connectivity.  ...  Whereas the change in local synchrony was only brief, dpFC lasted throughout the cognitive stage, indicating that short modulations of local synchrony can have persistent global effects.  ... 
doi:10.1371/journal.pcbi.1009407 pmid:35263318 pmcid:PMC8936493 fatcat:ptt4qfz2nvgnng3ujqi4oqgqwq

Whole-Brain Network Models: From Physics to Bedside

Anagh Pathak, Dipanjan Roy, Arpan Banerjee
2022 Frontiers in Computational Neuroscience  
Computational neuroscience has come a long way from its humble origins in the pioneering work of Hodgkin and Huxley.  ...  also offering mechanistic insights into large-scale cortical communication.  ...  AUTHOR CONTRIBUTIONS AP and AB conceived the study. AP wrote the first draft. AP, DR, and AB wrote and revised manuscript. All authors contributed to the article and approved the submitted version.  ... 
doi:10.3389/fncom.2022.866517 pmid:35694610 pmcid:PMC9180729 fatcat:zep32b7tpvh2fb3ce26t2togdm

Critique and Comparison of Prevailing Consciousness Models with a Novel Embodied Cognition Model

Ravinder Jerath, Connor Beveridge
2018 World Journal of Neuroscience  
The main goal of this review is to present the advantages in theoretical power of an embodied cognition, metastable model of consciousness manifest in the Default Space Theory by comparing it to other  ...  popular brain-based metastable models that though provide important insight into the cognitive nature of consciousness, are incomplete in their model of an architecture of consciousness.  ...  Author Contributions Theory developed by RJ with some writing with majority of the manuscript written by CB. Conflicts of Interest The authors declare no conflict of interest.  ... 
doi:10.4236/wjns.2018.83030 fatcat:j6zp6rupsfbt5kfa73ippcunie

Cortical operational synchrony during audio–visual speech integration

Andrew A. Fingelkurts, Alexander A. Fingelkurts, Christina M. Krause, Riikka Möttönen, Mikko Sams
2003 Brain and Language  
Using a robust phenomenon known as the McGurk effect it was shown in the present study that audio-visual synthesis takes place within a distributed and dynamic cortical networks with emergent properties  ...  Various cortical sites within these networks interact with each other by means of so-called operational synchrony (Kaplan et al., 1997) .  ...  Alexander Kaplan and Dr. Shishkin for their valuable discussions on the methodological issues. AAF were supported by Research Fellowship from CIMO, Finland.  ... 
doi:10.1016/s0093-934x(03)00059-2 pmid:12735946 fatcat:xqy65zwihfaatoaroggady5ofm

DMN Operational Synchrony Relates to Self-Consciousness: Evidence from Patients in Vegetative and Minimally Conscious States

Andrew A Fingelkurts, Alexander A Fingelkurts, Sergio Bagnato, Cristina Boccagni, Giuseppe Galardi
2012 The Open Neuroimaging Journal  
To fill this gap, EEG operational synchrony analysis [1, 2] was performed in patients with severe brain injuries in vegetative and minimally conscious states to study the strength of DMN operational synchrony  ...  We demonstrated that the strength of DMN EEG operational synchrony was smallest or even absent in patients in vegetative state, intermediate in patients in minimally conscious state and highest in healthy  ...  Authors declare no conflict of interests.  ... 
doi:10.2174/1874440001206010055 pmid:22905075 pmcid:PMC3419863 fatcat:6n3w6ptzhbbudk2e4clao3ptv4

Dynamic Network Mechanisms of Relational Integration

B. L. Parkin, P. J. Hellyer, R. Leech, A. Hampshire
2015 Journal of Neuroscience  
Based on these results, we propose that during RI an increase in network connectivity and a decrease in network metastability allows rules that are coded throughout working memory systems to be dynamically  ...  Nonetheless, when examining frontoparietal activity using analyses of phase synchrony and psychophysiological interactions, we observe increased network connectivity during RI alone.  ...  Again, there was a significant effect of RI on phase synchrony (t ϭ 3.23, p ϭ 0.005) and no effect of NSRs (t ϭ Ϫ0.75, p ϭ 0.46), demonstrating that the RI synchrony effect was widespread throughout much  ... 
doi:10.1523/jneurosci.4956-14.2015 pmid:25995457 pmcid:PMC4438120 fatcat:yekl3xhycrgcdkymawa4n7cygq

The role of the posterior cingulate cortex in cognition and disease

Robert Leech, David J. Sharp
2013 Brain  
metastability and so adjusts how stable brain network activity is over time.  ...  It is well protected against ischaemic stroke, and so there is relatively little neuropsychological data about the consequences of focal lesions.  ...  with high synchrony and low metastability.  ... 
doi:10.1093/brain/awt162 pmid:23869106 pmcid:PMC3891440 fatcat:bz7zimfwird4dmpxylhd5egqm4

Consciousness and Complexity [chapter]

2003 Essential Sources in the Scientific Study of Consciousness  
The network of highly interconnected cortical areas and thalamic nuclei that comprises a large part of the mammalian brain.  ...  . • Theory of neuronal group selection (TNGS). A large-scale selectionist theory of brain development and function with roots in evolutionary theory and immunology.  ...  In less dramatic cases focal cortical lesions can delete specific conscious contents; for example, damage to cortical region V4 can remove color dimensions from the space of possible experiences (cerebral  ... 
doi:10.7551/mitpress/2834.003.0072 fatcat:epqukx2w6rhuxejtnmsjeqej24

Metastability, criticality and phase transitions in brain and its models

Gerhard Werner
2007 Biosystems (Amsterdam. Print)  
, notably with reference to the role of reentrant activity in neural circuits of cerebral cortex and subcortical structures.  ...  This essay is designed to organize a range of experimental findings and theoretical insights of the past 25 years into a coherent view of the brain's style of function.  ...  Andrew and Alexander Fingelkurst kindly offered clarifying comments on an earlier version of the manuscript, which are here incorporated with their permission.  ... 
doi:10.1016/j.biosystems.2006.12.001 pmid:17316974 fatcat:4ogazthnh5cjnibybdrxgibile

Persistent operational synchrony within brain default-mode network and self-processing operations in healthy subjects

Andrew A. Fingelkurts, Alexander A. Fingelkurts
2011 Brain and Cognition  
Based on the theoretical analysis of self-consciousness concepts, we hypothesized that the spatiotemporal pattern of functional connectivity within the default-mode network (DMN) should persist unchanged  ...  In both studies for the majority of experimental trails we indeed found a constellation of operationally synchronized cortical areas (indexed as DMN) that was persistent across all studied experimental  ...  Acknowledgments The authors thank Carlos Neves (Computer Science specialist) for programming, technical, and IT support. Special thanks for English editing to Dmitry Skarin.  ... 
doi:10.1016/j.bandc.2010.11.015 pmid:21172727 fatcat:2qo257l2n5dwvd2aobzhx3fhve

New perspectives in pharmaco-electroencephalography

Andrew A. Fingelkurts, Alexander A. Fingelkurts, Seppo Kähkönen
2005 Progress in Neuro-psychopharmacology and Biological Psychiatry  
From this perspective, disruption is viewed as a disorder of the metastable balance between large-scale integration and independent processing in the brain, in favor of either independent or hyper-ordered  ...  This paper proposes that the future of psychopharmacology lies in its ability to design the psychotropic drugs which can restore the normal temporal structure and metastable structure of brain activity  ...  In this metastable regime ( Fig. 1) , the brain operates in a state that allows both integration and segregation of function (Friston, 1997; Bressler and Kelso, 2001) : individual neuronal networks are  ... 
doi:10.1016/j.pnpbp.2004.11.002 pmid:15694226 fatcat:cqfurgqc65f6lccdapt66im7zq
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