A key principle of brain organization is the functional integration of brain regions into interconnected networks. Functional MRI scans acquired at rest offer insights into functional integration via patterns of coherent fluctuations in spontaneous activity, known as functional connectivity. These patterns have been studied intensively and have been linked to cognition and disease. However, the field is fractionated. Diverging analysis approaches have segregated the community into research silos, limiting the replication and clinical translation of findings. A primary source of this fractionation is the diversity of approaches used to reduce complex brain data into a lower-dimensional set of features for analysis and interpretation, which we refer to as brain representations. In this Primer, we provide an overview of different brain representations, lay out the challenges that have led to the fractionation of the field and that continue to form obstacles for convergence, and propose concrete guidelines to unite the field.
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E.P.D. was supported by the SSNAP “Support for Sick and Newborn Infants and their Parents” Medical Research Fund (University of Oxford Excellence Fellowship). S.J.H. was supported by grant #2017-403 of the Strategic Focal Area “Personalized Health and Related Technologies (PHRT)” of the ETH Domain. S.S. is supported by a Wellcome Trust Strategic Award 098369/Z/12/Z and a Wellcome Trust Collaborative Award 215573/Z/19/Z. M.W. is supported by the NIHR Oxford Health Biomedical Research Centre and by the Wellcome Trust (106183/Z/14/Z and 215573/Z/19/Z). We thank M. Glasser for his helpful comments and discussions in relation to this article.
The authors declare that they have no conflicts of interest.
Peer review information Nature Neuroscience thanks Finnegan Calabro, Thomas Yeo and the other, anonymous, reviewer for their contribution to the peer review of this work.
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Bijsterbosch, J., Harrison, S.J., Jbabdi, S. et al. Challenges and future directions for representations of functional brain organization. Nat Neurosci 23, 1484–1495 (2020). https://doi.org/10.1038/s41593-020-00726-z