title: Effect of fMRI acoustic noise on sensorimotor activation examined using optical topography.
abstract: Functional magnetic resonance imaging (fMRI) is an important tool for noninvasively imaging the hemodynamic responses accompanying brain activity, but fMRI measurements are accompanied by loud acoustic noises resulting from Lorentz forces that cannot be completely excluded when the present technology is used. We used recorded fMRI acoustic noise and examined its effect on sensorimotor activation in optical topography measurement when subjects were instructed to tap the fingers of the right hand under a 23-dB non-noise condition and 46-, 56-, and 65-dB noise conditions. The results showed that the amplitude of the activation signal (relative change in concentration) for oxygenated hemoglobin in the sensorimotor cortex decreased with increasing noise. The activation signal for deoxygenated hemoglobin did not depend significantly on the noise level but did tend to decrease with increasing noise. These results suggest that fMRI acoustic noise affects the hemodynamics of cortical areas associated with the processing of information other than auditory information.
authors.affiliation: Department of Medical Philosophy, Graduate School of Medical Science, Kitasato University, 1-15-1 Kitasato, Sagamihara, Kanagawa 228-8555, Japan. dm04039k@st.kitasato-u.ac.jp
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Fuchino
authors.forename: Hiroki
authors.initials: H
authors.lastname: Sato
authors.forename: Atsushi
authors.initials: A
authors.lastname: Maki
authors.forename: Yukari
authors.initials: Y
authors.lastname: Yamamoto
authors.forename: Takusige
authors.initials: T
authors.lastname: Katura
authors.forename: Akiko
authors.initials: A
authors.lastname: Obata
authors.forename: Hideaki
authors.initials: H
authors.lastname: Koizumi
authors.forename: Takeshi
authors.initials: T
authors.lastname: Yoro
mesh_terms: D000328:Adult; D001143:Arousal / Q000502:physiology*; D001307:Auditory Perception / Q000502:physiology*; D001931:Brain Mapping; D004292:Dominance, Cerebral / Q000502:physiology; D005260:Female; D005385:Fingers / Q000294:innervation; D006454:Hemoglobins / Q000378:metabolism; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D009043:Motor Activity / Q000502:physiology; D009044:Motor Cortex / Q000502:physiology*; D009622:Noise; D010108:Oxyhemoglobins / Q000378:metabolism; D011930:Reaction Time / Q000502:physiology; D013003:Somatosensory Cortex / Q000502:physiology*; D013018:Sound Spectrography; D041623:Tomography, Optical Coherence
chemical_list: D006454:Hemoglobins; D010108:Oxyhemoglobins; C100003:deoxyhemoglobin