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.

  • Opinion
  • Published:

Rethinking segregation and integration: contributions of whole-brain modelling

Abstract

The brain regulates information flow by balancing the segregation and integration of incoming stimuli to facilitate flexible cognition and behaviour. The topological features of brain networks — in particular, network communities and hubs — support this segregation and integration but do not provide information about how external inputs are processed dynamically (that is, over time). Experiments in which the consequences of selective inputs on brain activity are controlled and traced with great precision could provide such information. However, such strategies have thus far had limited success. By contrast, recent whole-brain computational modelling approaches have enabled us to start assessing the effect of input perturbations on brain dynamics in silico.

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: Segregation and integration measures can be improved using whole-brain modelling.
Figure 2: Using whole-brain computational modelling.
Figure 3: Using the binding to extend our understanding of integration in the human brain.
Figure 4: Using perturbational segregation and integration measures to characterize health and disease.

Similar content being viewed by others

References

  1. Balduzzi, D. & Tononi, G. Integrated information in discrete dynamical systems: motivation and theoretical framework. PLoS Comput. Biol. 4, e1000091 (2008).

    Article  PubMed  PubMed Central  CAS  Google Scholar 

  2. Griffith, V. & Koch, C. Quantifying synergistic mutual information. arXiv [online], (2012).

    Google Scholar 

  3. Mudrik, L., Faivre, N. & Koch, C. Information integration without awareness. Trends Cogn. Sci. 18, 488–496 (2014).

    Article  PubMed  Google Scholar 

  4. Smith, S. M. et al. Correspondence of the brain's functional architecture during activation and rest. Proc. Natl Acad. Sci. USA 106, 13040–13045 (2009).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  5. Clausen, J. Ethical brain stimulation — neuroethics of deep brain stimulation in research and clinical practice. Eur. J. Neurosci. 32, 1152–1162 (2010).

    Article  PubMed  Google Scholar 

  6. Kringelbach, M. L. & Aziz, T. Z. Neuroethical principles of deep brain stimulation. World Neurosurg. 76, 518–519 (2011).

    Article  PubMed  Google Scholar 

  7. Sporns, O., Tononi, G. & Kotter, R. The human connectome: a structural description of the human brain. PLoS Comput. Biol. 1, e42 (2005).

    Article  PubMed  PubMed Central  CAS  Google Scholar 

  8. Deco, G. & Kringelbach, M. L. Great expectations: using whole-brain computational connectomics for understanding neuropsychiatric disorders. Neuron 84, 892–905 (2014).

    Article  CAS  PubMed  Google Scholar 

  9. Basser, P. J. & Pierpaoli, C. Microstructural and physiological features of tissues elucidated by quantitative-diffusion-tensor MRI. J. Magn. Reson. B 111, 209–219 (1996).

    Article  CAS  PubMed  Google Scholar 

  10. Beaulieu, C. The basis of anisotropic water diffusion in the nervous system — a technical review. NMR Biomed. 15, 435–455 (2002).

    Article  PubMed  Google Scholar 

  11. Hagmann, P. et al. MR connectomics: principles and challenges. J. Neurosci. Methods 194, 34–45 (2010).

    Article  PubMed  Google Scholar 

  12. Johansen-Berg, H. & Rushworth, M. F. Using diffusion imaging to study human connectional anatomy. Annu. Rev. Neurosci. 32, 75–94 (2009).

    Article  CAS  PubMed  Google Scholar 

  13. Jones, D. K. & Cercignani, M. Twenty-five pitfalls in the analysis of diffusion MRI data. NMR Biomed. 23, 803–820 (2010).

    Article  PubMed  Google Scholar 

  14. Bassett, D. S. et al. Dynamic reconfiguration of human brain networks during learning. Proc. Natl Acad. Sci. USA 108, 7641–7646 (2011).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  15. Stam, C. J. et al. Graph theoretical analysis of magnetoencephalographic functional connectivity in Alzheimer's disease. Brain 132, 213–224 (2009).

    Article  CAS  PubMed  Google Scholar 

  16. Snyder, A. Z. & Raichle, M. E. A brief history of the resting state: the Washington University perspective. Neuroimage 62, 902–910 (2012).

    Article  PubMed  Google Scholar 

  17. 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).

    Article  CAS  PubMed  Google Scholar 

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

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  19. Fox, M. D. & Raichle, M. E. Spontaneous fluctuations in brain activity observed with functional magnetic resonance imaging. Nat. Rev. Neurosci. 8, 700–711 (2007).

    Article  CAS  PubMed  Google Scholar 

  20. Craddock, R. C. et al. Imaging human connectomes at the macroscale. Nat. Methods 10, 524–539 (2013).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  21. Milham, M. P. Open neuroscience solutions for the connectome-wide association era. Neuron 73, 214–218 (2012).

    Article  CAS  PubMed  Google Scholar 

  22. Sporns, O. Connectome. Scholarpedia 5, 5584 (2010).

    Article  Google Scholar 

  23. Fox, M. D. & Greicius, M. Clinical applications of resting state functional connectivity. Front. Syst. Neurosci. 4, 19 (2010).

    PubMed  PubMed Central  Google Scholar 

  24. Fornito, A., Harrison, B. J., Zalesky, A. & Simons, J. S. Competitive and cooperative dynamics of large-scale brain functional networks supporting recollection. Proc. Natl Acad. Sci. USA 109, 12788–12793 (2012).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  25. Tagliazucchi, E. & Laufs, H. Decoding wakefulness levels from typical fMRI resting-state data reveals reliable drifts between wakefulness and sleep. Neuron 82, 695–708 (2014).

    Article  CAS  PubMed  Google Scholar 

  26. Power, J. D., Barnes, K. A., Snyder, A. Z., Schlaggar, B. L. & Petersen, S. E. Spurious but systematic correlations in functional connectivity MRI networks arise from subject motion. Neuroimage 59, 2142–2154 (2012).

    Article  PubMed  Google Scholar 

  27. Tagliazucchi, E. et al. Automatic sleep staging using fMRI functional connectivity data. Neuroimage 63, 63–72 (2012).

    Article  PubMed  Google Scholar 

  28. Power, J. D. et al. Methods to detect, characterize, and remove motion artifact in resting state fMRI. Neuroimage 84, 320–341 (2014).

    Article  PubMed  Google Scholar 

  29. Patel, A. X. et al. A wavelet method for modeling and despiking motion artifacts from resting-state fMRI time series. Neuroimage 95, 287–304 (2014).

    Article  PubMed  Google Scholar 

  30. Bullmore, E. & Sporns, O. Complex brain networks: graph theoretical analysis of structural and functional systems. Nat. Rev. Neurosci. 10, 186–198 (2009).

    Article  CAS  PubMed  Google Scholar 

  31. van den Heuvel, M. P. & Sporns, O. Network hubs in the human brain. Trends Cogn. Sci. 17, 683–696 (2013).

    Article  PubMed  Google Scholar 

  32. Sporns, O. Network attributes for segregation and integration in the human brain. Curr. Opin. Neurobiol. 23, 162–171 (2013).

    Article  CAS  PubMed  Google Scholar 

  33. Fornito, A., Zalesky, A. & Breakspear, M. Graph analysis of the human connectome: promise, progress, and pitfalls. Neuroimage 80, 426–444 (2013).

    Article  PubMed  Google Scholar 

  34. Stephan, K. E. et al. Computational analysis of functional connectivity between areas of primate cerebral cortex. Phil. Trans. R. Soc. Lond. B 355, 111–126 (2000).

    Article  CAS  Google Scholar 

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

    Article  PubMed  Google Scholar 

  36. Power, J. D. et al. Functional network organization of the human brain. Neuron 72, 665–678 (2011).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  37. Markov, N. T. et al. Cortical high-density counterstream architectures. Science 342, 1238406 (2013).

    Article  PubMed  PubMed Central  CAS  Google Scholar 

  38. Zamora-Lopez, G., Zhou, C. & Kurths, J. Cortical hubs form a module for multisensory integration on top of the hierarchy of cortical networks. Front. Neuroinform. 4, 1 (2010).

    PubMed  PubMed Central  Google Scholar 

  39. Tononi, G., Edelman, G. M. & Sporns, O. Complexity and coherency: integrating information in the brain. Trends Cogn. Sci. 2, 474–484 (1998).

    Article  CAS  PubMed  Google Scholar 

  40. Tononi, G., Sporns, O. & Edelman, G. M. A measure for brain complexity: relating functional segregation and integration in the nervous system. Proc. Natl Acad. Sci. USA 91, 5033–5037 (1994).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  41. Tononi, G. & Sporns, O. Measuring information integration. BMC Neurosci. 4, 31 (2003).

    Article  PubMed  PubMed Central  Google Scholar 

  42. Barrett, A. B. & Seth, A. K. Practical measures of integrated information for time-series data. PLoS Comput. Biol. 7, e1001052 (2011).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  43. Oizumi, M., Albantakis, L. & Tononi, G. From the phenomenology to the mechanisms of consciousness: Integrated Information Theory 3.0. PLoS Comput. Biol. 10, e1003588 (2014).

    Article  PubMed  PubMed Central  CAS  Google Scholar 

  44. Casali, A. G. et al. A theoretically based index of consciousness independent of sensory processing and behavior. Sci. Transl Med. 5, 198ra105 (2013).

    Article  PubMed  Google Scholar 

  45. Haken, H. Cooperative phenomena in systems far from thermal equilibrium and in nonphysical systems. Rev. Modern Phys. 47, 67–121 (1975).

    Article  Google Scholar 

  46. Breakspear, M. & Jirsa, V. K. in Handbook of Brain Connectivity (eds Jirsa, V. K. & McIntosh, A. R.) 3–64 (Springer, 2007).

    Book  Google Scholar 

  47. Cabral, J., Kringelbach, M. L. & Deco, G. Exploring the network dynamics underlying brain activity during rest. Prog. Neurobiol. 114, 102–131 (2014).

    Article  PubMed  Google Scholar 

  48. Brunel, N. & Wang, X. J. What determines the frequency of fast network oscillations with irregular neural discharges? I. Synaptic dynamics and excitation–inhibition balance. J. Neurophysiol. 90, 415–430 (2003).

    Article  PubMed  Google Scholar 

  49. Deco, G. et al. Resting-state functional connectivity emerges from structurally and dynamically shaped slow linear fluctuations. J. Neurosci. 33, 11239–11252 (2013).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  50. Zilles, K. & Amunts, K. Centenary of Brodmann's map — conception and fate. Nat. Rev. Neurosci. 11, 139–145 (2010).

    Article  CAS  PubMed  Google Scholar 

  51. Modha, D. S. & Singh, R. Network architecture of the long-distance pathways in the macaque brain. Proc. Natl Acad. Sci. USA 107, 13485–13490 (2010).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  52. Desikan, R. S. et al. An automated labeling system for subdividing the human cerebral cortex on MRI scans into gyral based regions of interest. Neuroimage 31, 968–980 (2006).

    Article  PubMed  Google Scholar 

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

    Article  PubMed  PubMed Central  CAS  Google Scholar 

  54. 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).

    Article  CAS  PubMed  Google Scholar 

  55. Honey, C. J. et al. Predicting human resting-state functional connectivity from structural connectivity. Proc. Natl Acad. Sci. USA 106, 2035–2040 (2009).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  56. 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).

    Article  PubMed  PubMed Central  CAS  Google Scholar 

  57. Deco, G. et al. Identification of optimal structural connectivity using functional connectivity and neural modeling. J. Neurosci. 34, 7910–7916 (2014).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  58. Deco, G. et al. How local excitation–inhibition ratio impacts the whole brain dynamics. J. Neurosci. 34, 7886–7898 (2014).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  59. Deco, G., Jirsa, V. K. & McIntosh, A. R. Resting brains never rest: computational insights into potential cognitive architectures. Trends Neurosci. 36, 268–274 (2013).

    Article  CAS  PubMed  Google Scholar 

  60. Deco, G., Jirsa, V. K. & McIntosh, A. R. Emerging concepts for the dynamical organization of resting-state activity in the brain. Nat. Rev. Neurosci. 12, 43–56 (2011).

    Article  CAS  PubMed  Google Scholar 

  61. Deco, G. & Jirsa, V. K. Ongoing cortical activity at rest: criticality, multistability, and ghost attractors. J. Neurosci. 32, 3366–3375 (2012).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  62. 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).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  63. Cabral, J. et al. Exploring mechanisms of spontaneous functional connectivity in MEG: how delayed network interactions lead to structured amplitude envelopes of band-pass filtered oscillations. Neuroimage 90, 423–435 (2014).

    Article  PubMed  Google Scholar 

  64. Freyer, F. et al. Biophysical mechanisms of multistability in resting-state cortical rhythms. J. Neurosci. 31, 6353–6361 (2011).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  65. Cover, T. M. & Thomas, J. A. Elements of Information Theory 2nd edn (Wiley, 2006).

    Google Scholar 

  66. Norwich, K. H. Information, Sensation and Perception (Academic, 2003).

    Google Scholar 

  67. Allen, E. A. et al. Tracking whole-brain connectivity dynamics in the resting state. Cereb. Cortex 24, 663–676 (2014).

    Article  PubMed  Google Scholar 

  68. Leonardi, N. & Van De Ville, D. On spurious and real fluctuations of dynamic functional connectivity during rest. Neuroimage 104, 430–436 (2015).

    Article  PubMed  Google Scholar 

  69. Engel, A. K. & Singer, W. Temporal binding and the neural correlates of sensory awareness. Trends Cogn. Sci. 5, 16–25 (2001).

    Article  PubMed  Google Scholar 

  70. Crick, F. & Koch, C. Towards a neurobiological theory of consciousness. Semin. Neurosci. 2, 263–275 (1990).

    Google Scholar 

  71. Boly, M. et al. Hierarchical clustering of brain activity during human nonrapid eye movement sleep. Proc. Natl Acad. Sci. USA 109, 5856–5861 (2012).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  72. Deco, G., Hagmann, P., Hudetz, A. G. & Tononi, G. Modeling resting-state functional networks when the cortex falls asleep: local and global changes. Cereb. Cortex 24, 3180–3194 (2014).

    Article  PubMed  Google Scholar 

  73. Kringelbach, M. L., Jenkinson, N., Owen, S. L. & Aziz, T. Z. Translational principles of deep brain stimulation. Nat. Rev. Neurosci. 8, 623–635 (2007).

    Article  CAS  PubMed  Google Scholar 

  74. Van Hartevelt, T. J. et al. Neural plasticity in human brain connectivity: the effects of long term deep brain stimulation of the subthalamic nucleus in Parkinson's disease. PLoS ONE 9, e86496 (2014).

    Article  PubMed  PubMed Central  CAS  Google Scholar 

  75. Kringelbach, M. L., Green, A. L. & Aziz, T. Z. Balancing the brain: resting state networks and deep brain stimulation. Front. Integrat. Neurosci. 5, 8 (2011).

    Google Scholar 

  76. Tognoli, E. & Kelso, J. A. The metastable brain. Neuron 81, 35–48 (2014).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  77. Fornito, A., Zalesky, A. & Breakspear, M. The connectomics of brain disorders. Nat. Rev. Neurosci. 16, 159–172 (2015).

    Article  CAS  PubMed  Google Scholar 

  78. Cuthbert, B. N. & Insel, T. R. Toward the future of psychiatric diagnosis: the seven pillars of RDoC. BMC Med. 11, 126 (2013).

    Article  PubMed  PubMed Central  Google Scholar 

  79. Trusheim, M. R., Berndt, E. R. & Douglas, F. L. Stratified medicine: strategic and economic implications of combining drugs and clinical biomarkers. Nat. Rev. Drug Discov. 6, 287–293 (2007).

    Article  CAS  PubMed  Google Scholar 

  80. Hagmann, P. et al. Mapping human whole-brain structural networks with diffusion MRI. PLoS ONE 2, e597 (2007).

    Article  PubMed  PubMed Central  Google Scholar 

  81. 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).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  82. Cabral, J., Hugues, E., Sporns, O. & Deco, G. Role of local network oscillations in resting-state functional connectivity. Neuroimage 57, 130–139 (2011).

    Article  PubMed  Google Scholar 

  83. Ritter, P., Schirner, M., McIntosh, A. R. & Jirsa, V. K. The virtual brain integrates computational modeling and multimodal neuroimaging. Brain Connect. 3, 121–145 (2013).

    Article  PubMed  PubMed Central  Google Scholar 

  84. Watts, D. & Strogatz, S. Collective dynamics of 'small-world' networks. Nature 393, 440–442 (1998).

    Article  CAS  PubMed  Google Scholar 

  85. Dang-Vu, T. T. et al. Spontaneous neural activity during human slow wave sleep. Proc. Natl Acad. Sci. USA 105, 15160–15165 (2008).

    Article  PubMed  PubMed Central  Google Scholar 

  86. Schabus, M. et al. Hemodynamic cerebral correlates of sleep spindles during human non-rapid eye movement sleep. Proc. Natl Acad. Sci. USA 104, 13164–13169 (2007).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

Download references

Acknowledgements

G.D. is supported by the European Research Council (ERC) Advanced grant: DYSTRUCTURE (no. 295129), by the Spanish Research Project SAF2010-16085, by the FP7-ICT BrainScales and by the Brain Network Recovery Group through the James S. McDonnell Foundation. G.T. is supported by the Paul Allen Family Foundation and by the James S. McDonnell Foundation. M.B. is supported by the Mind Science Foundation. M.L.K. is supported by the ERC Consolidator grant: CAREGIVING (no. 615539) and by the TrygFonden Charitable Foundation. The authors thank P. Maquet for agreeing to share the previously published sleep and wakefulness functional MRI data for the purposes of this article.

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

FURTHER INFORMATION

The Virtual Brain

PowerPoint slides

Glossary

Bifurcation

One of the basic tools to analyse dynamic systems. It is defined by qualitative changes in the asymptotic behaviour of the system ('attractors') under parameter variation.

Diffusion tensor imaging

(DTI). An MRI technique that takes advantage of the restricted diffusion of water through myelinated nerve fibres in the brain to enable inference of the anatomical connectivity between regions of the brain.

Edges

In a brain graph, edges denote anatomical or functional connections between nodes, which may indicate brain regions or neurons.

Graph theory

A branch of mathematics that deals with the formal description and analysis of graphs. A graph is simply defined as a set of nodes (vertices) that are linked by connections (edges) and can be directed or undirected.

Magnetoencephalography

(MEG). A method of measuring brain activity that involves the detection of minute perturbations in the extracranial magnetic field that are generated by the electrical activity of neuronal populations.

Mean-field models

Mean-field approximations consist of replacing the temporally averaged discharge rate of a cell with an equivalent momentary activity of a neural population (the ensemble average) that corresponds to the assumption of ergodicity. According to these approximations, each cell assembly is characterized by its activity population rate.

Metastability

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

Small-world architecture

This term is used to describe complex networks that have a combination of random and regular topological properties.

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Deco, G., Tononi, G., Boly, M. et al. Rethinking segregation and integration: contributions of whole-brain modelling. Nat Rev Neurosci 16, 430–439 (2015). https://doi.org/10.1038/nrn3963

Download citation

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1038/nrn3963

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