The human brain is organized into large-scale networks that can be noninvasively identified using functional connectivity (FC) functional magnetic resonance imaging. FC varies across individuals, and there is significant interest in associating individual variation in FC with external behavioral measures. However, only recently has FC variation been characterized by studying brain networks within individual humans. We review these recent efforts, and we argue that individual variation in FC networks comes in three distinct forms: 1) variability in connectional strength, in which brain regions in the same location have variable FC strength across subjects; 2) variability in spatial localization, in which regions exhibit the same connections across subjects, but are expanded/contracted or spatially displaced in specific subjects; and 3) topological variability, in which networks have variable sets of constituent nodes. Unfortunately, each of these three types of variation confounds attempts to measure the others, which significantly impacts research studying brain networks.
|Original language||English (US)|
|Number of pages||8|
|Journal||Current Opinion in Behavioral Sciences|
|State||Published - Aug 1 2021|
Bibliographical noteFunding Information:
This work was supported in part by the U.S. Department of Veterans Affairs Clinical Sciences Research and Development Service grant 1IK2CX001680 (E.M.G.). The views expressed in this article are those of the authors and do not necessarily reflect the position or policy of the Department of Veterans Affairs or the U.S. government.
© 2021 Elsevier Ltd