SCIENCE@home

High-amplitude cofluctuations in cortical activity drive functional connectivity

Farnaz Zamani Esfahlani,Youngheun Jo,Joshua Faskowitz,Lisa Byrge,Daniel P. Kennedy,O. Sporns,Richard F. Betzel

Published 2020 in Proceedings of the National Academy of Sciences of the United States of America

ABSTRACT

Significance Despite widespread applications, the origins of functional connectivity remain elusive. Here we analyze human functional neuroimaging data. We decompose resting-state functional connectivity across time to assess the contributions of moment-to-moment activity cofluctuations to the overall connectivity pattern. We show that functional connectivity is driven by a small number of high-amplitude frames. We show that these frames are underpinned by a specific mode of brain activity; that the topography of this mode gets modulated during in-scanner tasks; and that high-amplitude frames encode personalized, subject-specific information. In summary, our parameter-free method provides an exact mathematical link between functional connectivity and frame-wise cofluctuations, creating opportunities for studying both static and time-varying functional brain networks. Resting-state functional connectivity is used throughout neuroscience to study brain organization and to generate biomarkers of development, disease, and cognition. The processes that give rise to correlated activity are, however, poorly understood. Here we decompose resting-state functional connectivity using a temporal unwrapping procedure to assess the contributions of moment-to-moment activity cofluctuations to the overall connectivity pattern. This approach temporally resolves functional connectivity at a timescale of single frames, which enables us to make direct comparisons of cofluctuations of network organization with fluctuations in the blood oxygen level-dependent (BOLD) time series. We show that surprisingly, only a small fraction of frames exhibiting the strongest cofluctuation amplitude are required to explain a significant fraction of variance in the overall pattern of connection weights as well as the network’s modular structure. These frames coincide with frames of high BOLD activity amplitude, corresponding to activity patterns that are remarkably consistent across individuals and identify fluctuations in default mode and control network activity as the primary driver of resting-state functional connectivity. Finally, we demonstrate that cofluctuation amplitude synchronizes across subjects during movie watching and that high-amplitude frames carry detailed information about individual subjects (whereas low-amplitude frames carry little). Our approach reveals fine-scale temporal structure of resting-state functional connectivity and discloses that frame-wise contributions vary across time. These observations illuminate the relation of brain activity to functional connectivity and open a number of directions for future research.

PUBLICATION RECORD

CITATION MAP

EXTRACTION MAP

CLAIMS

  • No claims are published for this paper.

CONCEPTS

  • No concepts are published for this paper.

REFERENCES

Showing 1-88 of 88 references · Page 1 of 1

CITED BY

Showing 1-100 of 218 citing papers · Page 1 of 3

123
Next