title: Isolating the effects of surface vasculature in infant neuroimaging using short-distance optical channels: a combination of local and global effects.
abstract: Functional near-infrared spectroscopy (fNIRS) records hemodynamic changes in the cortex arising from neurovascular coupling. However, (noninvasive) fNIRS recordings also record surface vascular signals arising from noncortical sources (e.g., in the skull, skin, dura, and other tissues located between the sensors and the brain). A current and important focus in the fNIRS community is determining how to remove these noncortical vascular signals to reduce noise and to prevent researchers from erroneously attributing responses to cortical sources. The current study is the first to test a popular method for removing signals from the surface vasculature (removing short, 1 cm, channel recordings from long, 3 cm, channel recordings) in human infants, a population frequently studied using fNIRS. We find evidence that this method does remove surface vasculature signals and indicates the presence of both local and global surface vasculature signals. However, we do not find that the removal of this information changes the statistical inferences drawn from the data. This latter result not only questions the importance of removing surface vasculature responses for empiricists employing this method, but also calls for future research using other tasks (e.g., ones with a weaker initial result) with this population and possibly additional methods for removing signals arising from the surface vasculature in infants.
authors.affiliation: University of Rochester, Brain and Cognitive Sciences, Meliora Hall, Box 270268, Rochester, New York 14627, United States; University of Rochester, Rochester Center for Brain Imaging, 430 Elmwood Avenue, Box 278917, Rochester, New York 14627, United States; Princeton University, Peretsman-Scully Hall, Psychology Department, Princeton, New Jersey 08544, United States.
authors.forename: Lauren L
authors.initials: LL
authors.lastname: Emberson
authors.affiliation: University of Rochester , Brain and Cognitive Sciences, Meliora Hall, Box 270268, Rochester, New York 14627, United States.
authors.forename: Stephen L
authors.initials: SL
authors.lastname: Crosswhite
authors.affiliation: University of Rochester , The Institute of Optics, Wilmot Building, 275 Hutchinson Road, Rochester, New York 14627, United States.
authors.forename: James R
authors.initials: JR
authors.lastname: Goodwin
authors.affiliation: University of Rochester , The Institute of Optics, Wilmot Building, 275 Hutchinson Road, Rochester, New York 14627, United States.
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Berger
authors.affiliation: University of Rochester, Brain and Cognitive Sciences, Meliora Hall, Box 270268, Rochester, New York 14627, United States; University of Rochester, Rochester Center for Brain Imaging, 430 Elmwood Avenue, Box 278917, Rochester, New York 14627, United States.
authors.forename: Richard N
authors.initials: RN
authors.lastname: Aslin
keywords: functional near-infrared spectroscopy; infant; neurovascular; short channel; surface vasculature