title: A Near-Infrared Spectroscopy Study on Cortical Hemodynamic Responses to Normal and Whispered Speech in 3- to 7-Year-Old Children.
abstract: The purpose of this study was to assess cortical hemodynamic response patterns in 3- to 7-year-old children listening to two speech modes: normally vocalized and whispered speech. Understanding whispered speech requires processing of the relatively weak, noisy signal, as well as the cognitive ability to understand the speaker's reason for whispering.
  
  
  
  Near-infrared spectroscopy (NIRS) was used to assess changes in cortical oxygenated hemoglobin from 16 typically developing children.
  
  
  
  A profound difference in oxygenated hemoglobin levels between the speech modes was found over left ventral sensorimotor cortex. In particular, over areas that represent speech articulatory body parts and motion, such as the larynx, lips, and jaw, oxygenated hemoglobin was higher for whisper than for normal speech. The weaker stimulus, in terms of sound energy, thus induced the more profound hemodynamic response. This, moreover, occurred over areas involved in speech articulation, even though the children did not overtly articulate speech during measurements.
  
  
  
  Because whisper is a special form of communication not often used in daily life, we suggest that the hemodynamic response difference over left ventral sensorimotor cortex resulted from inner (covert) practice or imagination of the different articulatory actions necessary to produce whisper as opposed to normal speech.
authors.affiliation: Human Science Department, Kyushu University, Fukuoka, Japan.
authors.forename: Gerard B
authors.initials: GB
authors.lastname: Remijn
authors.affiliation: Research Center for Child Mental Development, Kanazawa University, Kanazawa, Japan.
authors.forename: Mitsuru
authors.initials: M
authors.lastname: Kikuchi
authors.affiliation: Research Center for Child Mental Development, Kanazawa University, Kanazawa, Japan.
authors.forename: Yuko
authors.initials: Y
authors.lastname: Yoshimura
authors.affiliation: Department of Psychiatry and Neurobiology, Graduate School of Medical Science, Kanazawa University, Kanazawa, Japan.
authors.forename: Kiyomi
authors.initials: K
authors.lastname: Shitamichi
authors.affiliation: Department of Psychiatry and Neurobiology, Graduate School of Medical Science, Kanazawa University, Kanazawa, Japan.
authors.forename: Sanae
authors.initials: S
authors.lastname: Ueno
authors.affiliation: Department of Anesthesiology, Graduate School of Medical Science, Kanazawa University, Kanazawa, Japan.
authors.forename: Tsunehisa
authors.initials: T
authors.lastname: Tsubokawa
authors.affiliation: Department of Psychology, Kanazawa University, Kanazawa, Japan.
authors.forename: Haruyuki
authors.initials: H
authors.lastname: Kojima
authors.affiliation: Research Center for Child Mental Development, Kanazawa University, Kanazawa, Japan.
authors.forename: Haruhiro
authors.initials: H
authors.lastname: Higashida
authors.affiliation: Department of Psychiatry and Neurobiology, Graduate School of Medical Science, Kanazawa University, Kanazawa, Japan.
authors.forename: Yoshio
authors.initials: Y
authors.lastname: Minabe
mesh_terms: D002540:Cerebral Cortex / Q000502:physiology*; D002560:Cerebrovascular Circulation / Q000502:physiology*; D002648:Child; D002675:Child, Preschool; D005260:Female; D006454:Hemoglobins / Q000378:metabolism; D006801:Humans; D008297:Male; D010100:Oxygen / Q000097:blood; D013018:Sound Spectrography; D019265:Spectroscopy, Near-Infrared; D013061:Speech Acoustics; D013067:Speech Perception / Q000502:physiology*
chemical_list: D006454:Hemoglobins; D010100:Oxygen