title: Speech motor planning and execution deficits in early childhood stuttering.
abstract: BACKGROUND
  Five to eight percent of preschool children develop stuttering, a speech disorder with clearly observable, hallmark symptoms: sound repetitions, prolongations, and blocks. While the speech motor processes underlying stuttering have been widely documented in adults, few studies to date have assessed the speech motor dynamics of stuttering near its onset. We assessed fundamental characteristics of speech movements in preschool children who stutter and their fluent peers to determine if atypical speech motor characteristics described for adults are early features of the disorder or arise later in the development of chronic stuttering.
  
  
  METHODS
  Orofacial movement data were recorded from 58 children who stutter and 43 children who do not stutter aged 4;0 to 5;11 (years; months) in a sentence production task. For single speech movements and multiple speech movement sequences, we computed displacement amplitude, velocity, and duration. For the phrase level movement sequence, we computed an index of articulation coordination consistency for repeated productions of the sentence.
  
  
  RESULTS
  Boys who stutter, but not girls, produced speech with reduced amplitudes and velocities of articulatory movement. All children produced speech with similar durations. Boys, particularly the boys who stuttered, had more variable patterns of articulatory coordination compared to girls.
  
  
  CONCLUSIONS
  This study is the first to demonstrate sex-specific differences in speech motor control processes between preschool boys and girls who are stuttering. The sex-specific lag in speech motor development in many boys who stutter likely has significant implications for the dramatically different recovery rates between male and female preschoolers who stutter. Further, our findings document that atypical speech motor development is an early feature of stuttering.
authors: Department of Speech, Language, and Hearing Sciences, Purdue University, Lyles Porter Hall, 715 Clinic Dr., West Lafayette, 47907-2122 IN USA.
authors: Bridget
authors: B
authors: Walsh
authors: University of Colorado Hospital, 12605 East 16th Ave., Aurora, CO USA.
authors: Kathleen Marie
authors: KM
authors: Mettel
authors: Department of Speech, Language, and Hearing Sciences, Purdue University, Lyles Porter Hall, 715 Clinic Dr., West Lafayette, 47907-2122 IN USA.
authors: Anne
authors: A
authors: Smith
keywords: Preschool children; Sex differences; Speech kinematics; Speech motor control; Speech production; Stuttering