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New Perspectives on Spontaneous Brain Activity: Dynamic Networks and Energy Matter
Spontaneous brain activity has received increasing attention as demonstrated by the exponential rise in the number of published article on this topic over the last 30 years. Such “intrinsic” brain activity, generated in the absence of an explicit task, is frequently associated with resting-state or...
Autores principales: | , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
Frontiers Media S.A.
2016
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Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4880557/ https://www.ncbi.nlm.nih.gov/pubmed/27303283 http://dx.doi.org/10.3389/fnhum.2016.00247 |
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author | Tozzi, Arturo Zare, Marzieh Benasich, April A. |
author_facet | Tozzi, Arturo Zare, Marzieh Benasich, April A. |
author_sort | Tozzi, Arturo |
collection | PubMed |
description | Spontaneous brain activity has received increasing attention as demonstrated by the exponential rise in the number of published article on this topic over the last 30 years. Such “intrinsic” brain activity, generated in the absence of an explicit task, is frequently associated with resting-state or default-mode networks (DMN)s. The focus on characterizing spontaneous brain activity promises to shed new light on questions concerning the structural and functional architecture of the brain and how they are related to “mind”. However, many critical questions have yet to be addressed. In this review, we focus on a scarcely explored area, specifically the energetic requirements and constraints of spontaneous activity, taking into account both thermodynamical and informational perspectives. We argue that the “classical” definitions of spontaneous activity do not take into account an important feature, that is, the critical thermodynamic energetic differences between spontaneous and evoked brain activity. Spontaneous brain activity is associated with slower oscillations compared with evoked, task-related activity, hence it exhibits lower levels of enthalpy and “free-energy” (i.e., the energy that can be converted to do work), thus supporting noteworthy thermodynamic energetic differences between spontaneous and evoked brain activity. Increased spike frequency during evoked activity has a significant metabolic cost, consequently, brain functions traditionally associated with spontaneous activity, such as mind wandering, require less energy that other nervous activities. We also review recent empirical observations in neuroscience, in order to capture how spontaneous brain dynamics and mental function can be embedded in a non-linear dynamical framework, which considers nervous activity in terms of phase spaces, particle trajectories, random walks, attractors and/or paths at the edge of the chaos. This takes us from the thermodynamic free-energy, to the realm of “variational free-energy”, a theoretical construct pertaining to probability and information theory which allows explanation of unexplored features of spontaneous brain activity. |
format | Online Article Text |
id | pubmed-4880557 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2016 |
publisher | Frontiers Media S.A. |
record_format | MEDLINE/PubMed |
spelling | pubmed-48805572016-06-14 New Perspectives on Spontaneous Brain Activity: Dynamic Networks and Energy Matter Tozzi, Arturo Zare, Marzieh Benasich, April A. Front Hum Neurosci Neuroscience Spontaneous brain activity has received increasing attention as demonstrated by the exponential rise in the number of published article on this topic over the last 30 years. Such “intrinsic” brain activity, generated in the absence of an explicit task, is frequently associated with resting-state or default-mode networks (DMN)s. The focus on characterizing spontaneous brain activity promises to shed new light on questions concerning the structural and functional architecture of the brain and how they are related to “mind”. However, many critical questions have yet to be addressed. In this review, we focus on a scarcely explored area, specifically the energetic requirements and constraints of spontaneous activity, taking into account both thermodynamical and informational perspectives. We argue that the “classical” definitions of spontaneous activity do not take into account an important feature, that is, the critical thermodynamic energetic differences between spontaneous and evoked brain activity. Spontaneous brain activity is associated with slower oscillations compared with evoked, task-related activity, hence it exhibits lower levels of enthalpy and “free-energy” (i.e., the energy that can be converted to do work), thus supporting noteworthy thermodynamic energetic differences between spontaneous and evoked brain activity. Increased spike frequency during evoked activity has a significant metabolic cost, consequently, brain functions traditionally associated with spontaneous activity, such as mind wandering, require less energy that other nervous activities. We also review recent empirical observations in neuroscience, in order to capture how spontaneous brain dynamics and mental function can be embedded in a non-linear dynamical framework, which considers nervous activity in terms of phase spaces, particle trajectories, random walks, attractors and/or paths at the edge of the chaos. This takes us from the thermodynamic free-energy, to the realm of “variational free-energy”, a theoretical construct pertaining to probability and information theory which allows explanation of unexplored features of spontaneous brain activity. Frontiers Media S.A. 2016-05-26 /pmc/articles/PMC4880557/ /pubmed/27303283 http://dx.doi.org/10.3389/fnhum.2016.00247 Text en Copyright © 2016 Tozzi, Zare and Benasich. http://creativecommons.org/licenses/by/4.0/ This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution and reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms. |
spellingShingle | Neuroscience Tozzi, Arturo Zare, Marzieh Benasich, April A. New Perspectives on Spontaneous Brain Activity: Dynamic Networks and Energy Matter |
title | New Perspectives on Spontaneous Brain Activity: Dynamic Networks and Energy Matter |
title_full | New Perspectives on Spontaneous Brain Activity: Dynamic Networks and Energy Matter |
title_fullStr | New Perspectives on Spontaneous Brain Activity: Dynamic Networks and Energy Matter |
title_full_unstemmed | New Perspectives on Spontaneous Brain Activity: Dynamic Networks and Energy Matter |
title_short | New Perspectives on Spontaneous Brain Activity: Dynamic Networks and Energy Matter |
title_sort | new perspectives on spontaneous brain activity: dynamic networks and energy matter |
topic | Neuroscience |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4880557/ https://www.ncbi.nlm.nih.gov/pubmed/27303283 http://dx.doi.org/10.3389/fnhum.2016.00247 |
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