title: Transient increase in systemic interferences in the superficial layer and its influence on event-related motor tasks: a functional near-infrared spectroscopy study.
abstract: Functional near-infrared spectroscopy (fNIRS) is a widely utilized neuroimaging tool in fundamental neuroscience research and clinical investigation. Previous research has revealed that task-evoked systemic artifacts mainly originating from the superficial-tissue may preclude the identification of cerebral activation during a given task. We examined the influence of such artifacts on event-related brain activity during a brisk squeezing movement. We estimated task-evoked superficial-tissue hemodynamics from short source–detector distance channels (15 mm) by applying principal component analysis. The estimated superficial-tissue hemodynamics exhibited temporal profiles similar to the canonical cerebral hemodynamic model. Importantly, this task-evoked profile was also observed in data from a block design motor experiment, suggesting a transient increase in superficial-tissue hemodynamics occurs following motor behavior, irrespective of task design. We also confirmed that estimation of event-related cerebral hemodynamics was improved by a simple superficial-tissue hemodynamic artifact removal process using 15-mm short distance channels, compared to the results when no artifact removal was applied. Thus, our results elucidate task design-independent characteristics of superficial-tissue hemodynamics and highlight the need for the application of superficial-tissue hemodynamic artifact removal methods when analyzing fNIRS data obtained during event-related motor tasks.
authors.affiliation: Nagaoka University of Technology, Graduate School of Engineering, Nagaoka, Japan.
authors.forename: Isao
authors.initials: I
authors.lastname: Nambu
authors.affiliation: Nagaoka University of Technology, Graduate School of Engineering, Nagaoka, JapanbATR Brain Information Communication Research Lab Group, Keihanna-Science City, Kyoto, Japan.
authors.forename: Takuya
authors.initials: T
authors.lastname: Ozawa
authors.affiliation: Nagaoka University of Technology, Graduate School of Engineering, Nagaoka, Japan.
authors.forename: Takanori
authors.initials: T
authors.lastname: Sato
authors.affiliation: ATR Brain Information Communication Research Lab Group, Keihanna-Science City, Kyoto, Japan.
authors.forename: Takatsugu
authors.initials: T
authors.lastname: Aihara
authors.affiliation: ATR Brain Information Communication Research Lab Group, Keihanna-Science City, Kyoto, Japan.
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Fujiwara
authors.affiliation: ATR Brain Information Communication Research Lab Group, Keihanna-Science City, Kyoto, JapancTokyo Bay Rehabilitation Hospital, Narashino, Chiba, JapandKeio University School of Medicine, Department of Rehabilitation Medicine, Shinjuku-ku, Tokyo, Japan.
authors.forename: Yohei
authors.initials: Y
authors.lastname: Otaka
authors.affiliation: ATR Brain Information Communication Research Lab Group, Keihanna-Science City, Kyoto, Japan.
authors.forename: Rieko
authors.initials: R
authors.lastname: Osu
authors.affiliation: ATR Brain Information Communication Research Lab Group, Keihanna-Science City, Kyoto, JapaneUniversity of Tsukuba, Faculty of Engineering, Information and System, Tsukuba, Ibaraki, Japan.
authors.forename: Jun
authors.initials: J
authors.lastname: Izawa
authors.affiliation: Nagaoka University of Technology, Graduate School of Engineering, Nagaoka, Japan.
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Wada
mesh_terms: D016477:Artifacts; D006439:Hemodynamics; D059906:Neuroimaging / Q000379:methods*; D019265:Spectroscopy, Near-Infrared