title: Modulation of radial blood flow during Braille character discrimination task.
abstract: OBJECTIVE
  Human hands are excellent in performing sensory and motor function. We have hypothesized that blood flow of the hand is dynamically regulated by sympathetic outflow during concentrated finger perception. To identify this hypothesis, we measured radial blood flow (RBF), radial vascular conductance (RVC), heart rate (HR), and arterial blood pressure (AP) during Braille reading performed under the blind condition in nine healthy subjects. The subjects were instructed to read a flat plate with raised letters (Braille reading) for 30 s by the forefinger, and to touch a blank plate as control for the Braille discrimination procedure.
  
  
  RESULTS
  HR and AP slightly increased during Braille reading but remained unchanged during the touching of the blank plate. RBF and RVC were reduced during the Braille character discrimination task (decreased by -46% and -49%, respectively). Furthermore, the changes in RBF and RVC were much greater during the Braille character discrimination task than during the touching of the blank plate (decreased by -20% and -20%, respectively).
  
  
  CONCLUSIONS
  These results have suggested that the distribution of blood flow to the hand is modulated via sympathetic nerve activity during concentrated finger perception.
authors.affiliation: Nagasaki University Department of Physical and Occupational Therapy, Graduate School of Biomedical Sciences 1-7-1 Sakamoto Nagasaki 852-8520 Japan. jmura@nagaski-u.ac.jp
authors.forename: Jun
authors.initials: J
authors.lastname: Murata
authors.forename: K
authors.initials: K
authors.lastname: Matsukawa
authors.forename: H
authors.initials: H
authors.lastname: Komine
authors.forename: H
authors.initials: H
authors.lastname: Tsuchimochi
mesh_terms: D001766:Blindness; D001794:Blood Pressure / Q000502:physiology; D004192:Discrimination, Psychological / Q000502:physiology; D005385:Fingers / Q000098:blood supply* / Q000294:innervation; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D008297:Male; D012039:Regional Blood Flow / Q000502:physiology*; D012682:Sensory Aids; D013564:Sympathetic Nervous System / Q000502:physiology; D014110:Touch / Q000502:physiology*; D055698:Touch Perception / Q000502:physiology*; D055815:Young Adult