Skip to main content

Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

  • Review Article
  • Published:

Emerging concepts for the dynamical organization of resting-state activity in the brain

Key Points

  • Spontaneous ongoing global activity of the brain at rest is highly structured in spatiotemporal patterns called resting-state networks.

  • Resting-state networks are related to the underlying neuroanatomical structure, but they emerge as a result of the interplay between dynamics and structure.

  • Resting-state networks therefore reflect the intrinsic properties of the brain network. These include neuroanatomical structure, local neuronal dynamics, signal transmission delays and genuine noise.

  • The formation and dissolution of resting-state networks reflects the exploration of possible functional network configurations around a stable anatomical framework.

  • Brain networks generally possess a small-world construction, in which there are multiple ways for different network elements to interact. This anatomical architecture provides the landscape within which different possible network configurations occur. In the absence of external stimulation, noise drives the network dynamics such that the system will visit these network configurations spontaneously.

  • Resting-state networks were originally characterized by indirect and slow measures of neuronal activity (for example, by blood oxygen level-dependent (BOLD) functional MRI (fMRI)). However, it is now clear that large-scale resting-state networks correlate with neuronal rhythms at faster frequencies.

Abstract

A broad body of experimental work has demonstrated that apparently spontaneous brain activity is not random. At the level of large-scale neural systems, as measured with functional MRI (fMRI), this ongoing activity reflects the organization of a series of highly coherent functional networks. These so-called resting-state networks (RSNs) closely relate to the underlying anatomical connectivity but cannot be understood in those terms alone. Here we review three large-scale neural system models of primate neocortex that emphasize the key contributions of local dynamics, signal transmission delays and noise to the emerging RSNs. We propose that the formation and dissolution of resting-state patterns reflects the exploration of possible functional network configurations around a stable anatomical skeleton.

This is a preview of subscription content, access via your institution

Access options

Buy this article

Prices may be subject to local taxes which are calculated during checkout

Figure 1: The evolution of the default mode network in the neuroscience literature.
Figure 2: Resting-state dynamics reflect interactions of the local dynamics through anatomical connections.
Figure 3: Resting-state networks emerge from a dynamic framework of noise, anatomical connectivity and time delays.
Figure 4: Ultra slowly varying resting-state networks resulting from noise-driven transitions between multistable states.

Similar content being viewed by others

References

  1. Pinneo, L. R. On noise in the nervous system. Psychol. Rev. 73, 242–247 (1966). An important paper in the archives of science that provides a compelling rationale for considering intrinsic activity as a vital part of brain function.

    CAS  PubMed  Google Scholar 

  2. Andreasen, N. C. et al. Remembering the past: two facets of episodic memory explored with positron emission tomography. Am. J. Psychiatry 152, 1576–1585 (1995).

    CAS  PubMed  Google Scholar 

  3. Nyberg, L. et al. Network analysis of positron emission tomography regional cerebral blood flow data: ensemble inhibition during episodic memory retrieval. J. Neurosci. 16, 3753–3759 (1996).

    CAS  PubMed  PubMed Central  Google Scholar 

  4. Shulman, G. L. et al. Common blood flow changes across visual tasks: II. Decreases in cerebral cortex. J. Cogn. Neurosci. 9, 648–663 (1997).

    CAS  PubMed  Google Scholar 

  5. Raichle, M. E. et al. A default mode of brain function. Proc. Natl Acad. Sci. USA 98, 676–682 (2001). The first complete articulation of the idea of a default mode of brain function based on both positron emission tomography (PET) blood flow studies and fMRI. This paper provided the framework for the study of intrinsic activity in neuroimaging.

    CAS  PubMed  PubMed Central  Google Scholar 

  6. Fair, D. A. et al. The maturing architecture of the brain's default network. Proc. Natl Acad. Sci. USA 105, 4028–4032 (2008).

    CAS  PubMed  PubMed Central  Google Scholar 

  7. Fransson, P. Spontaneous low-frequency BOLD signal fluctuations: an fMRI investigation of the resting-state default mode of brain function hypothesis. Hum. Brain Mapp. 26, 15–29 (2005).

    PubMed  PubMed Central  Google Scholar 

  8. Christoff, K., Gordon, A. M., Smallwood, J., Smith, R. & Schooler, J. W. Experience sampling during fMRI reveals default network and executive system contributions to mind wandering. Proc. Natl Acad. Sci. USA 106, 8719–8724 (2009).

    CAS  PubMed  PubMed Central  Google Scholar 

  9. Christoff, K. et al. Rostrolateral prefrontal cortex involvement in relational integration during reasoning. Neuroimage 14, 1136–1149 (2001).

    CAS  PubMed  Google Scholar 

  10. Vincent, J. L. et al. Intrinsic functional architecture in the anaesthetized monkey brain. Nature 447, 83–86 (2007). This paper showed that resting-state networks correspond to functional networks that are activated under specific task or stimulation conditions, and suggested a strong relationship between the underlying neuroanatomical connectivity and the resting-state patterns.

    CAS  PubMed  Google Scholar 

  11. Fukunaga, M. et al. Large-amplitude, spatially correlated fluctuations in BOLD fMRI signals during extended rest and early sleep stages. Magn. Reson. Imaging 24, 979–992 (2006).

    PubMed  Google Scholar 

  12. Horovitz, S. G. et al. Low frequency BOLD fluctuations during resting wakefulness and light sleep: a simultaneous EEG–fMRI study. Hum. Brain Mapp. 29, 671–682 (2008).

    PubMed  Google Scholar 

  13. Picchioni, D. et al. fMRI differences between early and late stage-1 sleep. Neurosci. Lett. 441, 81–85 (2008).

    CAS  PubMed  PubMed Central  Google Scholar 

  14. D'Esposito, M., Ballard, D., Aguirre, G. K. & Zarahn, E. Human prefrontal cortex is not specific for working memory: a functional MRI study. Neuroimage 8, 274–282 (1998).

    CAS  PubMed  Google Scholar 

  15. Poldrack, R. A. Can. cognitive processes be inferred from neuroimaging data? Trends Cogn. Sci. 10, 59–63 (2006).

    PubMed  Google Scholar 

  16. McIntosh, A. R. Towards a network theory of cognition. Neural Netw. 13, 861–876 (2000).

    CAS  PubMed  Google Scholar 

  17. McIntosh, A. R. Contexts and catalysts: a resolution of the localization and integration of function in the brain. Neuroinformatics 2, 175–182 (2004).

    PubMed  Google Scholar 

  18. Biswal, B., Yetkin, F. Z., Haughton, V. M. & Hyde, J. S. Functional connectivity in the motor cortex of resting human brain using echo-planar MRI. Magn. Reson. Med. 34, 537–541 (1995). This paper demonstrated that brain regions that activate jointly seem to maintain a high correlation of BOLD signal fluctuations at rest, identifying a 'resting-state network' of 'functionally connected' regions. The paper's method of analysis is now known as functional connectivity-by-MRI (fcMRI) or resting-state fMRI.

    CAS  PubMed  Google Scholar 

  19. Greicius, M. D., Krasnow, B., Reiss, A. L. & Menon, V. Functional connectivity in the resting brain: a network analysis of the default mode hypothesis. Proc. Natl Acad. Sci. USA 100, 253–258 (2003). This paper studied for the first time the resting-state connectivity analysis of the default mode and provided clear evidence for the existence of a cohesive default mode network. It also investigated how the default mode network is modulated by task demands and what functions it might serve.

    CAS  PubMed  Google Scholar 

  20. Lowe, M. J., Mock, B. J. & Sorenson, J. A. Functional connectivity in single and multislice echoplanar imaging using resting-state fluctuations. Neuroimage 7, 119–132 (1998).

    CAS  PubMed  Google Scholar 

  21. Rogers, B. P., Morgan, V. L., Newton, A. T. & Gore, J. C. Assessing functional connectivity in the human brain by fMRI. Magn. Reson. Imaging 25, 1347–1357 (2007).

    PubMed  PubMed Central  Google Scholar 

  22. Damoiseaux, J. S. et al. Consistent resting-state networks across healthy subjects. Proc. Natl Acad. Sci. USA 103, 13848–13853 (2006).

    CAS  PubMed  PubMed Central  Google Scholar 

  23. Fox, M. D. et al. The human brain is intrinsically organized into dynamic, anticorrelated functional networks. Proc. Natl Acad. Sci. USA 102, 9673–9678 (2005). This work was a compelling demonstration of at least two intrinsically coherent networks that could be captured using resting-state fMRI. The work led to the characterization as a task-positive and task-negative network, the latter corresponding to the default mode network

    CAS  PubMed  PubMed Central  Google Scholar 

  24. Fox, M. D., Zhang, D., Snyder, A. Z. & Raichle, M. E. The global signal and observed anticorrelated resting state brain networks. J. Neurophysiol. 101, 3270–3283 (2009). This paper investigated the anticorrelation between different resting-state networks, showing how the level of anticorrelation is affected by global signal removal. However, the authors demonstrated that several characteristics of anticorrelated networks are not attributable to global signal removal, suggesting that they have a biological basis.

    PubMed  PubMed Central  Google Scholar 

  25. Murphy, K., Birn, R. M., Handwerker, D. A., Jones, T. B. & Bandettini, P. A. The impact of global signal regression on resting state correlations: are anti-correlated networks introduced? Neuroimage 44, 893–905 (2009).

    PubMed  Google Scholar 

  26. Damoiseaux, J. S. et al. Reduced resting-state brain activity in the “default network” in normal aging. Cereb. Cortex 18, 1856–1864 (2007).

    PubMed  Google Scholar 

  27. Garrity, A. G. et al. Aberrant 'default mode' functional connectivity in schizophrenia. Am. J. Psychiatry 164, 450–457 (2007).

    PubMed  Google Scholar 

  28. Greicius, M. Resting-state functional connectivity in neuropsychiatric disorders. Curr. Opin. Neurol. 21, 424–430 (2008). This paper discusses how resting-state networks are disrupted in disorders in which cognition is also affected.

    PubMed  Google Scholar 

  29. Rombouts, S. A. et al. Model-free group analysis shows altered BOLD FMRI networks in dementia. Hum. Brain Mapp. 30, 256–266 (2009).

    PubMed  Google Scholar 

  30. Hagmann, P. et al. Mapping the structural core of human cerebral cortex. PLoS Biol. 6, e159 (2008).

    PubMed  PubMed Central  Google Scholar 

  31. Bullmore, E. & Sporns, O. Complex brain networks: graph theoretical analysis of structural and functional systems. Nature Rev. Neurosci. 10, 186–198 (2009). This is a comprehensive review of the principles of graph theory as they relate to brain networks. The empirical demonstrations are helpful in translating the measures to concrete applications.

    CAS  Google Scholar 

  32. Sporns, O. & Zwi, J. D. The small world of the cerebral cortex. Neuroinformatics 2, 145–162 (2004).

    PubMed  Google Scholar 

  33. Greicius, M. D., Supekar, K., Menon, V. & Dougherty, R. F. Resting-state functional connectivity reflects structural connectivity in the default mode network. Cereb. Cortex 19, 72–78 (2009).

    PubMed  Google Scholar 

  34. Honey, C. J. et al. Predicting human resting-state functional connectivity from structural connectivity. Proc. Natl Acad. Sci. USA 106, 2035–2040 (2009). This paper used computational methods to compare anatomical and fMRI connectivity in humans. The authors concluded that the large-scale anatomical structure of the human cerebral cortex may constrain, but does not entirely account for, the observed global functional connectivity.

    CAS  PubMed  PubMed Central  Google Scholar 

  35. Koch, M. A., Norris, D. G. & Hund-Georgiadis, M. An investigation of functional and anatomical connectivity using magnetic resonance imaging. Neuroimage 16, 241–250 (2002).

    PubMed  Google Scholar 

  36. Honey, C. J., Kotter, R., Breakspear, M. & Sporns, O. Network structure of cerebral cortex shapes functional connectivity on multiple time scales. Proc. Natl Acad. Sci. USA 104, 10240–10245 (2007).

    CAS  PubMed  PubMed Central  Google Scholar 

  37. Ghosh, A., Rho, Y., McIntosh, A. R., Kotter, R. & Jirsa, V. K. Noise during rest enables the exploration of the brain's dynamic repertoire. PLoS Comput. Biol. 4, e1000196 (2008). This paper proposed that the space–time structure of coupling and time delays in the presence of noise define a dynamic framework for the emergence of activity fluctuations in the resting brain. It showed that fluctuations destabilize the ground state, producing excursion in the dynamical repertoire of the global brain network that results in oscillations structured in the experimentally observed resting-state subnetworks.

    PubMed  PubMed Central  Google Scholar 

  38. Deco, G., Jirsa, V., McIntosh, A. R., Sporns, O. & Kotter, R. Key role of coupling, delay, and noise in resting brain fluctuations. Proc. Natl Acad. Sci. USA 106, 10302–10307 (2009). This paper considered that resting-state ultraslow oscillations, and in particular the emergence of anticorrelated subnetworks, result from fluctuation-driven transitions between multistable states. Here, multistable cluster synchronization states appear in coupled oscillator systems owing to the delay of transmission times, highlighting the importance of the space–time structure of couplings in networks.

    CAS  PubMed  PubMed Central  Google Scholar 

  39. Valdes-Sosa, P. A. et al. Model driven EEG/fMRI fusion of brain oscillations. Hum. Brain Mapp. 30, 2701–2721 (2009).

    PubMed  Google Scholar 

  40. Bojak, I., Oostendorp, T. F., Reid, A. T. & Kotter, R. Connecting mean field models of neural activity to EEG and fMRI data. Brain Topogr. 23, 139–149 (2010).

    PubMed  Google Scholar 

  41. Izhikevich, E. M. & Edelman, G. M. Large-scale model of mammalian thalamocortical systems. Proc. Natl Acad. Sci. USA 105, 3593–3598 (2008).

    CAS  PubMed  PubMed Central  Google Scholar 

  42. Hlinka, J. & Coombes, S. Depolarization induced suppression of excitation and the emergence of ultraslow rhythms in neural networks. Phys. Rev. Lett. 104, 068101 (2010).

    CAS  PubMed  Google Scholar 

  43. Steyn-Ross, D. A. & Steyn-Ross, M. (eds) Modeling Phase Transitions in the Brain (Springer, 2010).

    Google Scholar 

  44. Kotter, R. Online retrieval, processing, and visualization of primate connectivity data from the CoCoMac database. Neuroinformatics 2, 127–144 (2004).

    PubMed  Google Scholar 

  45. Stephan, K. E. et al. Advanced database methodology for the Collation of Connectivity data on the Macaque brain (CoCoMac). Phil. Trans. R. Soc. Lond. B 356, 1159–1186 (2001).

    CAS  Google Scholar 

  46. Kotter, R. & Wanke, E. Mapping brains without coordinates. Phil. Trans. R. Soc. Lond. B 360, 751–766 (2005).

    Google Scholar 

  47. Friston, K. J., Mechelli, A., Turner, R. & Price, C. J. Nonlinear responses in fMRI: the Balloon model, Volterra kernels, and other hemodynamics. Neuroimage 12, 466–477 (2000).

    CAS  PubMed  Google Scholar 

  48. Tzourio-Mazoyer, N. et al. Automated anatomical labeling of activations in SPM using a macroscopic anatomical parcellation of the MNI MRI single-subject brain. Neuroimage 15, 273–289 (2002).

    CAS  PubMed  Google Scholar 

  49. Monto, S., Palva, S., Voipio, J. & Palva, J. M. Very slow EEG fluctuations predict the dynamics of stimulus detection and oscillation amplitudes in humans. J. Neurosci. 28, 8268–8272 (2008).

    CAS  PubMed  PubMed Central  Google Scholar 

  50. Nir, Y. et al. Interhemispheric correlations of slow spontaneous neuronal fluctuations revealed in human sensory cortex. Nature Neurosci. 11, 1100–1108 (2008).

    CAS  PubMed  Google Scholar 

  51. McNamara, B. & Wiesenfeld, K. Theory of stochastic resonance. Phys. Rev. A 39, 4854–4869 (1989).

    CAS  Google Scholar 

  52. Chawla, D., Lumer, E. D. & Friston, K. J. Relating macroscopic measures of brain activity to fast, dynamic neuronal interactions. Neural Comput. 12, 2805–2821 (2000).

    CAS  PubMed  Google Scholar 

  53. Chawla, D., Lumer, E. D. & Friston, K. J. The relationship between synchronization among neuronal populations and their mean activity levels. Neural Comput. 11, 1389–1411 (1999).

    CAS  PubMed  Google Scholar 

  54. Zemanová, L., Zhou, C. & Kurths, J. Structural and functional clusters of complex brain networks. Physica D 224, 202–212 (2006).

    Google Scholar 

  55. Zhou, C., Zemanova, L., Zamora, G., Hilgetag, C. C. & Kurths, J. Hierarchical organization unveiled by functional connectivity in complex brain networks. Phys. Rev. Lett. 97, 238103 (2006).

    PubMed  Google Scholar 

  56. Zhou, Y. et al. Functional dysconnectivity of the dorsolateral prefrontal cortex in first-episode schizophrenia using resting-state fMRI. Neurosci. Lett. 417, 297–302 (2007).

    CAS  PubMed  Google Scholar 

  57. Acebron, J. A., Bonilla, L. L., Perez Vicente, C. J., Ritort, F. & Spigler, R. The Kuramoto model: a simple paradigm for synchronization phenomena. Rev. Mod. Phys. 77, 137–185 (2005).

    Google Scholar 

  58. Kuramoto, Y. in Lecture Notes in Physics (ed. Araki, H.) 420 (Springer, New York, 1975).

    Google Scholar 

  59. Kenet, T., Bibitchkov, D., Tsodyks, M., Grinvald, A. & Arieli, A. Spontaneously emerging cortical representations of visual attributes. Nature 425, 954–956 (2003).

    CAS  PubMed  Google Scholar 

  60. Arieli, A., Sterkin, A., Grinvald, A. & Aertsen, A. Dynamics of ongoing activity: explanation of the large variability in evoked cortical responses. Science 273, 1868–1871 (1996). This study used optical imaging in the cat visual cortex to characterize the dynamics of spontaneous activity at rest. It showed that the variability of stimulus-evoked activity is largely accounted for by variation in spontaneous activity.

    CAS  PubMed  Google Scholar 

  61. Blumenfeld, B., Bibitchkov, D. & Tsodyks, M. Neural network model of the primary visual cortex: from functional architecture to lateral connectivity and back. J. Comput. Neurosci. 20, 219–241 (2006).

    PubMed  PubMed Central  Google Scholar 

  62. Muller-Linow, M., Hilgetag, C. C. & Hutt, M. T. Organization of excitable dynamics in hierarchical biological networks. PLoS Comput. Biol. 4, e1000190 (2008).

    PubMed  PubMed Central  Google Scholar 

  63. Lippe, S., Kovacevic, N. & McIntosh, A. R. Differential maturation of brain signal complexity in the human auditory and visual system. Front. Hum. Neurosci. 3, 48 (2009).

    PubMed  PubMed Central  Google Scholar 

  64. McIntosh, A. R., Kovacevic, N. & Itier, R. J. Increased brain signal variability accompanies lower behavioral variability in development. PLoS Comput. Biol. 4, e1000106 (2008).

    PubMed  PubMed Central  Google Scholar 

  65. Garrett, D. D., Kovacevic, N., McIntosh, A. R. & Grady, C. L. Blood oxygen level-dependent signal variability is more than just noise. J. Neurosci. 30, 4914–4921 (2010).

    CAS  PubMed  PubMed Central  Google Scholar 

  66. Fox, M. D., Snyder, A. Z., Zacks, J. M. & Raichle, M. E. Coherent spontaneous activity accounts for trial-to-trial variability in human evoked brain responses. Nature Neurosci. 9, 23–25 (2006). This paper demonstrated that coherent spontaneous fluctuations in human brain activity account for a substantial fraction of the variability in measured event-related BOLD responses, and that spontaneous and task-related activity are linearly superimposed in the human brain.

    CAS  PubMed  Google Scholar 

  67. Vincent, J. L. et al. Coherent spontaneous activity identifies a hippocampal-parietal memory network. J. Neurophysiol. 96, 3517–3531 (2006).

    PubMed  Google Scholar 

  68. Faisal, A. A., Selen, L. P. & Wolpert, D. M. Noise in the nervous system. Nature Rev. Neurosci. 9, 292–303 (2008).

    CAS  Google Scholar 

  69. Knill, D. C. & Pouget, A. The Bayesian brain: the role of uncertainty in neural coding and computation. Trends Neurosci. 27, 712–719 (2004).

    CAS  PubMed  Google Scholar 

  70. Pouget, A., Dayan, P. & Zemel, R. S. Inference and computation with population codes. Annu. Rev. Neurosci. 26, 381–410 (2003).

    CAS  PubMed  Google Scholar 

  71. Mantini, D., Perrucci, M. G., Del Gratta, C., Romani, G. L. & Corbetta, M. Electrophysiological signatures of resting state networks in the human brain. Proc. Natl Acad. Sci. USA 104, 13170–13175 (2007).

    CAS  PubMed  PubMed Central  Google Scholar 

  72. Gao, W. et al. Evidence on the emergence of the brain's default network from 2-week-old to 2-year-old healthy pediatric subjects. Proc. Natl Acad. Sci. USA 106, 6790–6795 (2009).

    CAS  PubMed  PubMed Central  Google Scholar 

  73. Grady, C. L. et al. A multivariate analysis of age-related differences in default mode and task-positive networks across multiple cognitive domains. Cereb. Cortex 20, 1432–1447 (2009).

    PubMed  Google Scholar 

  74. Jirsa, V. K. & Haken, H. Field theory of electromagnetic brain activity. Phys. Rev. Lett. 77, 960–963 (1996).

    CAS  PubMed  Google Scholar 

  75. Jirsa, V. K. & Haken, H. A derivation of a macroscopic field theory of the brain from the quasi-microscopic neural dynamics. Physica D 99, 503–526 (1997).

    Google Scholar 

  76. Robinson, P. A., Rennie, C. J. & Wright, J. J. Propagation and stability of waves of electrical activity in the cerebral cortex. Phys. Rev. E 56, 826–840 (1997).

    CAS  Google Scholar 

  77. Breakspear, M. et al. A unifying explanation of primary generalized seizures through nonlinear brain modeling and bifurcation analysis. Cereb. Cortex 16, 1296–1313 (2006).

    CAS  PubMed  Google Scholar 

  78. Nunez, P. L. The brain wave equation: a model for the EEG. Math. Biosci. 21, 279–297 (1974).

    Google Scholar 

  79. Rodriguesz, S., Terry, J. R. & Breakspear, M. On the genesis of spike–wave oscillations in a mean-field model of human corticothalamic dynamics. Phys. Lett. A 355, 352–357 (2006).

    Google Scholar 

  80. Horwitz, B. & Husain, F. T. in Handbook on Brain Connectivity (eds Jirsa, V. K. & McIntosh, A. R.) 275–302 (Springer, New York, 2007).

    Google Scholar 

  81. Tuckwell, H. C. Introduction to Theoretical Neurobiology (Cambridge Univ. Press, 1988).

    Google Scholar 

  82. Knight, B. W., Omurtag, A. & Sirovich, L. The approach of a neuron population firing rate to a new equilibrium: an exact theoretical result. Neural Comput. 12, 1045–1055 (2000).

    CAS  PubMed  Google Scholar 

  83. Wilson, H. R. & Cowan, J. D. Excitatory and inhibitory interactions in localized populations of model neurons. Biophys. J. 12, 1–24 (1972).

    CAS  PubMed  PubMed Central  Google Scholar 

  84. Assisi, C. G., Jirsa, V. K. & Kelso, J. A. Synchrony and clustering in heterogeneous networks with global coupling and parameter dispersion. Phys. Rev. Lett. 94, 018106 (2005).

    PubMed  Google Scholar 

  85. Stefanescu, R. A. & Jirsa, V. K. A low dimensional description of globally coupled heterogeneous neural networks of excitatory and inhibitory neurons. PLoS Comput. Biol. 4, e1000219 (2008).

    PubMed  PubMed Central  Google Scholar 

Download references

Acknowledgements

We are grateful for funding received from the James S. McDonnell Foundation (grant Brain NRG [JSMF22002082]).

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to Gustavo Deco.

Ethics declarations

Competing interests

The authors declare no competing financial interests.

Related links

Related links

FURTHER INFORMATION

Gustavo Deco's homepage

Viktor K. Jirsa's homepage

Anthony R. McIntosh's homepage

Glossary

Oxygen extraction

A quantitative medical imaging method to determine the regional consumption of oxygen in brain tissue.

BOLD fMRI

Blood oxygen level-dependent (BOLD) functional MRI (fMRI) is a relatively new neuroimaging tool to map activity in the brain in vivo. Signal changes are dependent on the relative changes in blood oxygen levels in the brain capillary beds.

Functional connectivity

The relationship between activity in two or more neural sources. This usually refers to the temporal correlation between sources but has been extended to include correlations across trials or different experimental subjects. Functional connectivity methods include estimation of correlation coefficients and coherence. The estimation cannot be used to infer the direction of the relation between sources.

Diffusion spectrum imaging

An MRI technique that is similar to DTI, but with the added capability of resolving multiple directions of diffusion in each voxel of white matter. This allows multiple groups of fibres at each location, including intersecting fibre pathways, to be mapped.

Graph theory

A branch of mathematics that deals with the formal description and analysis of graphs. A graph is defined as a set of nodes (vertices) linked by connections (edges). The connections may be directed or undirected. A graph provides an abstract representation of the system's elements and their interaction.

Small-world architecture

A term derived from graph theory estimation referring to a network that combines high levels of local clustering among nodes (to form families or cliques) and short paths that globally link all nodes of the network.

Diffusion tensor imaging

(Often abbreviated to DTI.) An MRI technique that takes advantage of the restricted diffusion of water through myelinated nerve fibres in the brain to infer the anatomical connectivity between brain areas.

Neural field

Values of neural activity that are defined over a continuous physical space, typically the two- or three-dimensional cortical sheet.

Transient

In dynamical systems this refers to time-dependent states evolving towards an attractor.

Balloon–Windkessel haemodynamic model

A dynamical model in which neural activity (the BOLD signal) is transduced into brain perfusion changes. In this model, the BOLD signal is taken to be a static nonlinear function of normalized total deoxyhaemoglobin voxel content, normalized venous volume, resting net oxygen extraction fraction by the capillary bed and resting blood volume fraction.

Stability

In dynamical systems refers to a state that, if it is perturbed, will return after a time to the same configuration.

Instability

In dynamical systems refers to a state that, if it is perturbed, will escape away from the original configuration.

Carrier wave

A wave of a higher frequency that is modulated with another signal of a lower frequency, typically for the purpose of conveying information.

Hopf bifurcation

In nonlinear dynamics, a local bifurcation in which an initially stable fixed point of a dynamical system loses its stability in an oscillatory fashion.

Attractor

In dynamical systems refers to a set towards which a system evolves. Geometrically, this set may be a point, a curve or a manifold.

Metastability

In dynamical systems refers to a state that falls outside the natural equilibrium state of the system, but that persists for an extended period of time.

Rights and permissions

Reprints and permissions

About this article

Cite this article

Deco, G., Jirsa, V. & McIntosh, A. Emerging concepts for the dynamical organization of resting-state activity in the brain. Nat Rev Neurosci 12, 43–56 (2011). https://doi.org/10.1038/nrn2961

Download citation

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1038/nrn2961

This article is cited by

Search

Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing