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Noise during rest enables the exploration of the brain’s dynamic repertoire| old_uid | 4963 |
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| title | Noise during rest enables the exploration of the brain’s dynamic repertoire |
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| start_date | 2008/05/30 |
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| schedule | 10h30 |
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| online | no |
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| summary | Traditionally brain function is studied through measuring physiological responses in controlled sensory, motor and cognitive paradigms. However, even at rest, in absence of overt goal-directed behaviour, collections of cortical regions consistently show temporally coherent activity (Greicius MD, Krasnow B, Reiss AL, Menon V (2003) Functional connectivity in the resting brain: a network analysis of the default mode hypothesis. Proc Natl Acad Sci USA 100:253-258 ; Damoiseaux JS, Rombouts SARB, Barkhof F, Scheltens P, Stam CJ, Smith SM, Beckmann CF (2006) Consistent resting-state networks across healthy subjects. Proc Natl Acad Sci USA 103:13848-13853). In humans, these resting state networks have been shown to greatly overlap with functional architectures present during consciously directed activity, which motivates the interpretation of rest activity as day dreaming, free association, stream of consciousness and inner rehearsal. In monkeys, it has been shown though those similar coherent fluctuations are present during deep anaesthesia when there is no consciousness (Vincent JL, Patel GH, Fox MD, Snyder AZ, Baker JT, Van Essen DC, Zempel JM, Snyder LH, Corbetta M, Raichle ME (2007) Intrinsic functional architecture in the anaesthetized monkey brain. Nature 447:83-86.). Here, we show that comparable resting state networks emerge from a stability analysis of the network dynamics using biologically realistic primate brain connectivity, although anatomical information alone does not identify the network. We specifically demonstrate that noise and time delays via propagation along connecting fibres are essential for the emergence of the coherent fluctuations of the default network. This combination of anatomical structure, local dynamics and neural noise enables the brain to explore various functional configurations, which represents its dynamic repertoire. |
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| oncancel | Rectification de date |
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| responsibles | Burle, Blanc, Roll |
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