title: Lag structure in resting-state fMRI.
abstract: The discovery that spontaneous fluctuations in blood oxygen level-dependent (BOLD) signals contain information about the functional organization of the brain has caused a paradigm shift in neuroimaging. It is now well established that intrinsic brain activity is organized into spatially segregated resting-state networks (RSNs). Less is known regarding how spatially segregated networks are integrated by the propagation of intrinsic activity over time. To explore this question, we examined the latency structure of spontaneous fluctuations in the fMRI BOLD signal. Our data reveal that intrinsic activity propagates through and across networks on a timescale of ∼1 s. Variations in the latency structure of this activity resulting from sensory state manipulation (eyes open vs. closed), antecedent motor task (button press) performance, and time of day (morning vs. evening) suggest that BOLD signal lags reflect neuronal processes rather than hemodynamic delay. Our results emphasize the importance of the temporal structure of the brain's spontaneous activity.
authors.affiliation: Department of Radiology, Washington University, St. Louis, Missouri; anishmitra@wustl.edu.
authors.forename: A
authors.initials: A
authors.lastname: Mitra
authors.affiliation: Department of Radiology, Washington University, St. Louis, Missouri; Department of Neurology, Washington University, St. Louis, Missouri.
authors.forename: A Z
authors.initials: AZ
authors.lastname: Snyder
authors.affiliation: Department of Biomedical Engineering, Washington University, St. Louis, Missouri; and.
authors.forename: C D
authors.initials: CD
authors.lastname: Hacker
authors.affiliation: Department of Radiology, Washington University, St. Louis, Missouri; Department of Neurology, Washington University, St. Louis, Missouri.
authors.forename: M E
authors.initials: ME
authors.lastname: Raichle
mesh_terms: D000465:Algorithms; D001921:Brain / Q000502:physiology*; D001931:Brain Mapping / Q000379:methods*; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D009415:Nerve Net / Q000502:physiology*; D010101:Oxygen Consumption / Q000502:physiology; D011930:Reaction Time / Q000502:physiology; D015203:Reproducibility of Results; D012146:Rest / Q000502:physiology*; D012680:Sensitivity and Specificity; D055815:Young Adult
keywords: dynamics; fMRI; functional connectivity; resting state