title: Multichannel fNIRS assessment of overt and covert confrontation naming.
abstract: Confrontation naming tasks assess cognitive processes involved in the main stage of word production. However, in fMRI, the occurrence of movement artifacts necessitates the use of covert paradigms, which has limited clinical applications. Thus, we explored the feasibility of adopting multichannel functional near-infrared spectroscopy (fNIRS) to assess language function during covert and overt naming tasks. Thirty right-handed, healthy adult volunteers underwent both naming tasks and cortical hemodynamics measurement using fNIRS. The overt naming task recruited the classical left-hemisphere language areas (left inferior frontal, superior and middle temporal, precentral, and postcentral gyri) exemplified by an increase in the oxy-Hb signal. Activations were bilateral in the middle and superior temporal gyri. However, the covert naming task recruited activation only in the left-middle temporal gyrus. The activation patterns reflected a major part of the functional network for overt word production, suggesting the clinical importance of fNIRS in the diagnosis of aphasic patients.
authors.affiliation: Functional Brain Science Laboratory, Center for Development of Advanced Medical Technology, Jichi Medical University, Shimotsuke, Tochigi, Japan.
authors.forename: Ayano
authors.initials: A
authors.lastname: Moriai-Izawa
authors.forename: Haruka
authors.initials: H
authors.lastname: Dan
authors.forename: Ippeita
authors.initials: I
authors.lastname: Dan
authors.forename: Toshifumi
authors.initials: T
authors.lastname: Sano
authors.forename: Keiji
authors.initials: K
authors.lastname: Oguro
authors.forename: Hidenori
authors.initials: H
authors.lastname: Yokota
authors.forename: Daisuke
authors.initials: D
authors.lastname: Tsuzuki
authors.forename: Eiju
authors.initials: E
authors.lastname: Watanabe
mesh_terms: D000328:Adult; D001931:Brain Mapping / Q000379:methods*; D002540:Cerebral Cortex / Q000098:blood supply / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012815:Signal Processing, Computer-Assisted; D019265:Spectroscopy, Near-Infrared; D013060:Speech / Q000502:physiology*; D055815:Young Adult