title: Voice and fluency changes as a function of speech task and deep brain stimulation.
abstract: OBJECTIVE
  Speaking, which naturally occurs in different modes or "tasks" such as conversation and repetition, relies on intact basal ganglia nuclei. Recent studies suggest that voice and fluency parameters are differentially affected by speech task. In this study, the authors examine the effects of subcortical functionality on voice and fluency, comparing measures obtained from spontaneous and matched repeated speech samples.
  
  
  METHODS
  Subjects with Parkinson's disease who were being treated with bilateral deep brain stimulation (DBS) of the subthalamic nuclei were tested with stimulators ON and OFF.
  
  
  RESULTS
  The study found that a voice measure, harmonic to noise ratio, is improved in repetition and in the DBS-ON condition and that dysfluencies are more plentiful in conversation with little or variable influence of DBS condition.
  
  
  CONCLUSIONS
  These findings suggest that voice and fluency are differentially affected by DBS treatment and that task conditions, interacting with subcortical functionality, influence motor speech performance.
authors.affiliation: The Nathan Kline Institute for Psychiatric Research, Orangeburg, NY, USA. diana.sidtis@nyu.edu
authors.forename: Diana
authors.initials: D
authors.lastname: Van Lancker Sidtis
authors.forename: Tiffany
authors.initials: T
authors.lastname: Rogers
authors.forename: Violette
authors.initials: V
authors.lastname: Godier
authors.forename: Michele
authors.initials: M
authors.lastname: Tagliati
authors.forename: John J
authors.initials: JJ
authors.lastname: Sidtis
mesh_terms: D000704:Analysis of Variance; D001479:Basal Ganglia / Q000502:physiology / Q000503:physiopathology; D046690:Deep Brain Stimulation; D006801:Humans; D008297:Male; D008875:Middle Aged; D010300:Parkinson Disease / Q000503:physiopathology / Q000628:therapy*; D013060:Speech / Q000502:physiology*; D013068:Speech Production Measurement; D014705:Verbal Behavior / Q000502:physiology*; D014833:Voice Quality / Q000502:physiology*