?url_ver=Z39.88-2004&rft_id=arXiv%3A1708.07046&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Adc&rft.relation=http%3A%2F%2Feprints.imtlucca.it%2F3997%2F&rft.title=Uncovering+functional+brain+signature+via+random+matrix+theory&rft.creator=Almog%2C+Assaf&rft.creator=Roethler%2C+Ori&rft.creator=Buijink%2C+Renate&rft.creator=Michel%2C+Stephan&rft.creator=Meijer%2C+Johanna+H&rft.creator=Rohling%2C+Jos+H+T&rft.creator=Garlaschelli%2C+Diego&rft.subject=QC+Physics&rft.subject=RC0321+Neuroscience.+Biological+psychiatry.+Neuropsychiatry&rft.description=The+brain+is+organized+in+a+modular+way%2C+serving+multiple+functionalities.+This+multiplicity+requires+that+both+positive+(e.g.+excitatory%2C+phase-coherent)+and+negative+(e.g.+inhibitory%2C+phase-opposing)+interactions+take+place+across+brain+modules.+Unfortunately%2C+most+methods+to+detect+modules+from+time+series+either+neglect+or+convert+to+positive+any+measured+negative+correlation.+This+may+leave+a+significant+part+of+the+sign-dependent+functional+structure+undetected.+Here+we+present+a+novel+method%2C+based+on+random+matrix+theory%2C+for+the+identification+of+sign-dependent+modules+in+the+brain.+Our+method+filters+out+the+joint+effects+of+local+(unit-specific)+noise+and+global+(system-wide)+dependencies+that+empirically+obfuscate+such+structure.+The+method+is+guaranteed+to+identify+an+optimally+contrasted+functional+%60signature%26%2339%3B%2C+i.e.+a+partition+into+modules+that+are+positively+correlated+internally+and+negatively+correlated+across.+The+method+is+purely+data-driven%2C+does+not+use+any+arbitrary+threshold+or+network+projection%2C+and+outputs+only+statistically+significant+structure.+In+measurements+of+neuronal+gene+expression+in+the+biological+clock+of+mice%2C+the+method+systematically+uncovers+two+otherwise+undetectable%2C+negatively+correlated+modules+whose+relative+size+and+mutual+interaction+strength+are+found+to+depend+on+photoperiod.+The+neurons+alternating+between+the+two+modules+define+a+candidate+region+of+functional+plasticity+for+circadian+modulation.&rft.publisher=arXiv&rft.date=2017&rft.type=Working+Paper&rft.type=NonPeerReviewed&rft.format=application%2Fpdf&rft.language=en&rft.rights=cc_by_nc&rft.identifier=http%3A%2F%2Feprints.imtlucca.it%2F3997%2F1%2F1708.07046.pdf&rft.identifier=++Almog%2C+Assaf+and+Roethler%2C+Ori+and+Buijink%2C+Renate+and+Michel%2C+Stephan+and+Meijer%2C+Johanna+H+and+Rohling%2C+Jos+H+T+and+Garlaschelli%2C+Diego++Uncovering+functional+brain+signature+via+random+matrix+theory.++Working+Paper+++arXiv+++++++(Submitted)+++&rft.relation=https%3A%2F%2Farxiv.org%2Fpdf%2F1708.07046&rft.relation=arXiv%3A1708.07046