title: An introduction to normalization and calibration methods in functional MRI.
abstract: In functional magnetic resonance imaging (fMRI), the blood oxygenation level dependent (BOLD) signal is often interpreted as a measure of neural activity. However, because the BOLD signal reflects the complex interplay of neural, vascular, and metabolic processes, such an interpretation is not always valid. There is growing evidence that changes in the baseline neurovascular state can result in significant modulations of the BOLD signal that are independent of changes in neural activity. This paper introduces some of the normalization and calibration methods that have been proposed for making the BOLD signal a more accurate reflection of underlying brain activity for human fMRI studies.
authors.affiliation: Center for Functional MRI, University of California San Diego, 9500 Gilman Drive, MC 0677, La Jolla, CA, 92093, USA, ttliu@ucsd.edu.
authors.forename: Thomas T
authors.initials: TT
authors.lastname: Liu
authors.forename: Gary H
authors.initials: GH
authors.lastname: Glover
authors.forename: Bryon A
authors.initials: BA
authors.lastname: Mueller
authors.forename: Douglas N
authors.initials: DN
authors.lastname: Greve
authors.forename: Gregory G
authors.initials: GG
authors.lastname: Brown
mesh_terms: D002138:Calibration; D059907:Functional Neuroimaging / Q000379:methods* / Q000592:standards; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods* / Q000592:standards; D008962:Models, Theoretical
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