title: Can brain state be manipulated to emphasize individual differences in functional connectivity?
abstract: While neuroimaging studies typically collapse data from many subjects, brain functional organization varies between individuals, and characterizing this variability is crucial for relating brain activity to behavioral phenotypes. Rest has become the default state for probing individual differences, chiefly because it is easy to acquire and a supposed neutral backdrop. However, the assumption that rest is the optimal condition for individual differences research is largely untested. In fact, other brain states may afford a better ratio of within- to between-subject variability, facilitating biomarker discovery. Depending on the trait or behavior under study, certain tasks may bring out meaningful idiosyncrasies across subjects, essentially enhancing the individual signal in networks of interest beyond what can be measured at rest. Here, we review theoretical considerations and existing work on how brain state influences individual differences in functional connectivity, present some preliminary analyses of within- and between-subject variability across conditions using data from the Human Connectome Project, and outline questions for future study.
authors.affiliation: Interdepartmental Neuroscience Program, Yale University, New Haven, CT, USA. Electronic address: emily.finn@yale.edu.
authors.forename: Emily S
authors.initials: ES
authors.lastname: Finn
authors.affiliation: Department of Radiology and Biomedical Imaging, Yale School of Medicine, New Haven, CT, USA.
authors.forename: Dustin
authors.initials: D
authors.lastname: Scheinost
authors.affiliation: Department of Radiology and Biomedical Imaging, Yale School of Medicine, New Haven, CT, USA.
authors.forename: Daniel M
authors.initials: DM
authors.lastname: Finn
authors.affiliation: Department of Radiology and Biomedical Imaging, Yale School of Medicine, New Haven, CT, USA.
authors.forename: Xilin
authors.initials: X
authors.lastname: Shen
authors.affiliation: Department of Radiology and Biomedical Imaging, Yale School of Medicine, New Haven, CT, USA; Department of Biomedical Engineering, Yale University, New Haven, CT, USA.
authors.forename: Xenophon
authors.initials: X
authors.lastname: Papademetris
authors.affiliation: Interdepartmental Neuroscience Program, Yale University, New Haven, CT, USA; Department of Radiology and Biomedical Imaging, Yale School of Medicine, New Haven, CT, USA; Department of Neurosurgery, Yale School of Medicine, New Haven, CT, USA.
authors.forename: R Todd
authors.initials: RT
authors.lastname: Constable
mesh_terms: D001921:Brain / Q000502:physiology*; D001931:Brain Mapping; D063132:Connectome / Q000379:methods; D006801:Humans; D007206:Individuality; D009415:Nerve Net / Q000502:physiology*; D009434:Neural Pathways / Q000502:physiology*; D012146:Rest / Q000502:physiology
keywords: Brain state; Functional connectivity; Human Connectome Project; Individual differences; Resting state; Scan condition; Task; fMRI