Basic kinematic parameters in the speech movements of children who stutter.

摘要

The goal of the current study was to assess whether the basic kinematic parameters of speech movements differ between children who stutter and their typically developing peers. Basic kinematic parameters of speech movements, such as their duration, displacement, and velocity, have been found to be an indicator of speech motor development (Riely & Smith, 2003). We hypothesized that children who stutter lag their normally developing peers as indicated by producing movements of lower velocity, larger displacement, and longer durations reflecting greater reliance on feedback mechanisms in speech motor control. We further investigated whether and how these parameters change when subjects repeat sentences with increased length and linguistic complexity. Fifty-six children who stutter and 42 typically developing peers repeated the phrase "buy Bobby a puppy" 8 times, and a subgroup of these children repeated two longer, more linguistically complex sentences with this phrase embedded. Movements of the lower lip + jaw were recorded and their duration, displacement, and velocity were computed. The children who stutter had significantly longer durations of "buy Bobby a puppy" than the controls, but no differences were found in the displacement and velocity measurements. Furthermore, no group differences were observed in how the basic kinematic parameters changed across the three different linguistic contexts. Both groups decreased duration, decreased displacement, and decreased velocity of movements when the length and linguistic demands of the sentence increased. We concluded that the basic kinematic parameters underlying speech motor control for children who stutter do not differ from their typically developing peers.