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.

  • Research Briefing
  • Published:

Multimodal evidence suggests the linearity of brain dynamics at the macroscale

We compared a range of linear and nonlinear models based on how accurately they could describe resting-state functional magnetic resonance imaging and intracranial electroencephalography dynamics in humans. Linear autoregressive models were the most accurate in all cases. Using numerical simulations, we demonstrated that spatiotemporal averaging has a critical and robust role in this linearity.

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

Fig. 1: Spatiotemporal averaging has a strong linearizing effect on nonlinear dynamics.

References

  1. Breakspear, M. Dynamic models of large-scale brain activity. Nat. Neurosci. 20, 340–352 (2017). A review article that presents an overview of different classes of linear and nonlinear models most commonly used for modelling large-scale brain dynamics, as well as the theory and assumptions underlying them.

    Article  CAS  PubMed  Google Scholar 

  2. Stam, C. J. Nonlinear dynamical analysis of EEG and MEG: review of an emerging field. Clin. Neurophysiol. 116, 2266–2301 (2005). A review article on various methods for analysis and estimation of nonlinearity in brain signals using indirect measures from nonlinear dynamical systems theory (also known as chaos theory).

    Article  CAS  PubMed  Google Scholar 

  3. Ahmed, S. & Nozari, E. On the linearizing effect of spatial averaging in large-scale populations of homogeneous nonlinear systems. In Proc. 2023 IEEE CDC 641–648 (IEEE, 2023). Follow-up study mathematically proving macroscopic linearity under spatial averaging.

  4. Ahmed, S. & Nozari, E. On the linearizing effect of temporal averaging in nonlinear dynamical systems. In Proc. 2023 ACC 4185–4190 (IEEE, 2023). Follow-up study mathematically proving macroscopic linearity under temporal averaging.

  5. Acharya, G., Davis, K. A. & Nozari, E. Predictive modeling of evoked intracranial EEG response to medial temporal lobe stimulation in patients with epilepsy. Preprint at bioRxiv https://doi.org/10.1101/2023.08.07.552297 (2023). Follow-up study showing that iEEG dynamics become switched-linear under electrical stimulation.

Download references

Additional information

Publisher’s note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

This is a summary of: Nozari, E. et al. Macroscopic resting-state brain dynamics are best described by linear models. Nat. Biomed. Eng. https://doi.org/10.1038/s41551-023-01117-y (2023).

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Multimodal evidence suggests the linearity of brain dynamics at the macroscale. Nat. Biomed. Eng 8, 7–8 (2024). https://doi.org/10.1038/s41551-023-01127-w

Download citation

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1038/s41551-023-01127-w

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