title: Temporal integration of auditory and vestibular stimuli.
abstract: OBJECTIVE
  Integration of balance-related cues from the vestibular and other sensory systems requires that they be perceived simultaneously despite arriving asynchronously at the central nervous system. Failure to perform temporal integration of multiple sensory signals represents a novel mechanism to explain symptoms in patients with imbalance. This study tested the ability of normal observers to compensate for sensory asynchronies between vestibular and auditory inputs.
  
  
  METHODS
  Double-blinded experimental design.
  
  
  METHODS
  We performed whole-body rotations about the earth-vertical axis following a raised-cosine trajectory at 0.5 and 1.0 Hz to several peak velocities up to a maximum of 180°/s in five normal subjects. Headphones were used to present a diotic auditory stimulus at various times relative to the onset of the rotation. Subjects were required to indicate which cue occurred first.
  
  
  RESULTS
  The vestibular stimulus needed to be presented 61 milliseconds (at a stimulus frequency of 0.5 Hz) and 19 milliseconds (at 1.0 Hz) before the auditory stimulus. Stimuli presented within a window of 300 milliseconds (at 0.5 Hz) to 200 milliseconds (at 1.0 Hz) were judged to be simultaneous.
  
  
  CONCLUSIONS
  The central nervous system must accommodate for delays in perception of vestibular and other sensory cues. Inaccurate temporal integration of these inputs represents a novel explanation for symptoms of imbalance.
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, Washington University School of Medicine, St Louis, Missouri 63110, USA.
authors.forename: Nai-Yuan N
authors.initials: NY
authors.lastname: Chang
authors.forename: Rosalie M
authors.initials: RM
authors.lastname: Uchanski
authors.forename: Timothy E
authors.initials: TE
authors.lastname: Hullar
mesh_terms: D000161:Acoustic Stimulation / Q000379:methods*; D001844:Bone Conduction / Q000502:physiology*; D003463:Cues; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D008297:Male; D009039:Motion Perception / Q000502:physiology; D011434:Proprioception / Q000502:physiology*; D011930:Reaction Time; D012016:Reference Values; D012399:Rotation; D012684:Sensory Thresholds / Q000502:physiology*; D013701:Temporal Bone / Q000502:physiology; D014722:Vestibule, Labyrinth / Q000502:physiology*; D055815:Young Adult