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Task-driven activity reduces the cortical activity space of the brain: experiment and whole-brain modeling

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dc.contributor.author Deco, Gustavo
dc.contributor.author He, Biyu J.
dc.contributor.author Ponce-Alvarez, Adrián
dc.contributor.author Hagmann, Patric
dc.date.accessioned 2016-04-22T09:02:29Z
dc.date.available 2016-04-22T09:02:29Z
dc.date.issued 2015
dc.identifier.citation Ponce-Alvarez A, Biyu J He, Hagmann P, Deco G. Task-driven activity reduces the cortical activity space of the brain: experiment and whole-brain modeling. PLoS Comput Biol. 2015;11(8):e100445. doi:10.1371/journal.pcbi.1004445
dc.identifier.issn 1553-734X
dc.identifier.uri http://hdl.handle.net/10230/26161
dc.description.abstract How a stimulus or a task alters the spontaneous dynamics of the brain remains a fundamental open question in neuroscience. One of the most robust hallmarks of task/stimulus-driven brain dynamics is the decrease of variability with respect to the spontaneous level, an effect seen across multiple experimental conditions and in brain signals observed at different spatiotemporal scales. Recently, it was observed that the trial-to-trial variability and temporal variance of functional magnetic resonance imaging (fMRI) signals decrease in the task-driven activity. Here we examined the dynamics of a large-scale model of the human cortex to provide a mechanistic understanding of these observations. The model allows computing the statistics of synaptic activity in the spontaneous condition and in putative tasks determined by external inputs to a given subset of brain regions. We demonstrated that external inputs decrease the variance, increase the covariances, and decrease the autocovariance of synaptic activity as a consequence of single node and large-scale network dynamics. Altogether, these changes in network statistics imply a reduction of entropy, meaning that the spontaneous synaptic activity outlines a larger multidimensional activity space than does the task-driven activity. We tested this model’s prediction on fMRI signals from healthy humans acquired during rest and task conditions and found a significant decrease of entropy in the stimulus-driven activity. Altogether, our study proposes a mechanism for increasing the information capacity of brain networks by enlarging the volume of possible activity configurations at rest and reliably settling into a confined stimulus-driven state to allow better transmission of stimulus-related information.
dc.description.sponsorship APA was supported by SEMAINE ERA-Net NEURON Project. GD was supported by the ERC Advanced Grant: DYSTRUCTURE (n. 295129), and the FP7-ICT BrainScales. PH was supported by Leenaards Foundation. BJH was supported by the Intramural Research Program of the National Institutes of Health, National Institute of Neurological Disorders and Stroke. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.
dc.format.mimetype application/pdf
dc.language.iso eng
dc.publisher Public Library of Science (PLoS)
dc.relation.ispartof PLoS Computational Biology. 2015;11(8):e100445
dc.rights This is an open access article, free of all/ncopyright, and may be freely reproduced, distributed,/ntransmitted, modified, built upon, or otherwise used/nby anyone for any lawful purpose. The work is made/navailable under the Creative Commons CC0 public/ndomain dedication.
dc.rights.uri https://creativecommons.org/publicdomain/zero/1.0/
dc.title Task-driven activity reduces the cortical activity space of the brain: experiment and whole-brain modeling
dc.type info:eu-repo/semantics/article
dc.identifier.doi http://dx.doi.org/10.1371/journal.pcbi.1004445
dc.relation.projectID info:eu-repo/grantAgreement/EC/FP7/295129
dc.relation.projectID info:eu-repo/grantAgreement/EC/FP7/269921
dc.rights.accessRights info:eu-repo/semantics/openAccess
dc.type.version info:eu-repo/semantics/publishedVersion


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