title: Denoising the speaking brain: toward a robust technique for correcting artifact-contaminated fMRI data under severe motion.
abstract: A comprehensive set of methods based on spatial independent component analysis (sICA) is presented as a robust technique for artifact removal, applicable to a broad range of functional magnetic resonance imaging (fMRI) experiments that have been plagued by motion-related artifacts. Although the applications of sICA for fMRI denoising have been studied previously, three fundamental elements of this approach have not been established as follows: 1) a mechanistically-based ground truth for component classification; 2) a general framework for evaluating the performance and generalizability of automated classifiers; and 3) a reliable method for validating the effectiveness of denoising. Here we perform a thorough investigation of these issues and demonstrate the power of our technique by resolving the problem of severe imaging artifacts associated with continuous overt speech production. As a key methodological feature, a dual-mask sICA method is proposed to isolate a variety of imaging artifacts by directly revealing their extracerebral spatial origins. It also plays an important role for understanding the mechanistic properties of noise components in conjunction with temporal measures of physical or physiological motion. The potentials of a spatially-based machine learning classifier and the general criteria for feature selection have both been examined, in order to maximize the performance and generalizability of automated component classification. The effectiveness of denoising is quantitatively validated by comparing the activation maps of fMRI with those of positron emission tomography acquired under the same task conditions. The general applicability of this technique is further demonstrated by the successful reduction of distance-dependent effect of head motion on resting-state functional connectivity.
authors.affiliation: Language Section, Voice, Speech, and Language Branch, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, MD 20892, USA. Electronic address: xuyi@nidcd.nih.gov.
authors.forename: Yisheng
authors.initials: Y
authors.lastname: Xu
authors.affiliation: Clinical Brain Disorders Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, MD 20892, USA.
authors.forename: Yunxia
authors.initials: Y
authors.lastname: Tong
authors.affiliation: Language Section, Voice, Speech, and Language Branch, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, MD 20892, USA.
authors.forename: Siyuan
authors.initials: S
authors.lastname: Liu
authors.affiliation: Language Section, Voice, Speech, and Language Branch, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, MD 20892, USA.
authors.forename: Ho Ming
authors.initials: HM
authors.lastname: Chow
authors.affiliation: Language Section, Voice, Speech, and Language Branch, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, MD 20892, USA; Department of Linguistics, University of Maryland, College Park, MD 20742, USA.
authors.forename: Nuria Y
authors.initials: NY
authors.lastname: AbdulSabur
authors.affiliation: Department of Bioengineering, University of Pennsylvania, Philadelphia, PA 19104, USA.
authors.forename: Govind S
authors.initials: GS
authors.lastname: Mattay
authors.affiliation: Language Section, Voice, Speech, and Language Branch, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, MD 20892, USA.
authors.forename: Allen R
authors.initials: AR
authors.lastname: Braun
mesh_terms: D000328:Adult; D000465:Algorithms; D016477:Artifacts; D001921:Brain / Q000502:physiology*; D001931:Brain Mapping / Q000379:methods*; D005260:Female; D019416:Head Movements; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D009038:Motion; D055815:Young Adult
keywords: Independent component analysis; Motion artifacts; Resting-state functional connectivity; Speech production; fMRI