A motor differentiation model for liquid substitutions : English /r/ variants in normal and disordered acquisition

Research output: Conference Papers (RGC: 31A, 31B, 32, 33)32_Refereed conference paper (without host publication)peer-review

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Author(s)

  • Bryan Gick
  • Barbara Bernhardt
  • Penelope Bacsfalvi
  • Ian Wilson
  • Sun Young OH

Detail(s)

Original languageEnglish
Publication statusPublished - 28 Sept 2007

Conference

TitleUltrafest IV
PlaceUnited States
CityNew York
Period28 - 29 September 2007

Abstract

Infants simplify arm reaching tasks by locking joints (Berthier & Keen 2006), therebyreducing kinematic degrees of freedom. Similar simplification has been observed in lipjawcoordination in children’s speech (Green & al. 2000). A model is described in whichboth normal and disordered learners contending with developing motor systems generallystrive to reduce the degrees of freedom of complex anatomical structures (e.g., thetongue). The specific claim is pursued that segmental substitutions (e.g., /w/ replacing /r/or /l/) are the result of compensation strategies which aim to simplify the complexity ofthe articulatory task. The proposal that gestural simplification may dictate substitutionstrategies for liquid consonants has been suggested previously (Studdert-Kennedy &Goldstein 2003). The present paper uses ultrasound imaging to evaluate /r/ productions ofnormal and disordered language learners in the contex of a motor differentiation model.Data are presented from ultrasound studies of: successful postvocalic /r/ production of an11-month-old female English speaker, /r/ production of 3-5-year-old English speakers,and /r/ production in the speech of adolescent English speakers with speech and hearingdisorders. Results indicate that successful /r/ production consistently corresponds withdifferentiated tongue shapes, even for extremely young speakers, while unsuccessful /r/production corresponds with undifferentiated tongue shapes.References:Berthier, N. E. & R. Keen. 2006. Development of reaching in infancy. ExperimentalBrain Research 169, 4: 507-518.Green, J. R., C. A. Moore, M. Higashikawa, R. W. Steeve. 2000. The physiologicdevelopment of speech motor control: Lip and jaw coordination. JSLHR 43: 239-255.Studdert-Kennedy, M. & L. M. Goldstein. 2003. Launching language: The gestural originof dicrete infinity. In Morten Christiansen and Simon Kirby (eds.) LanguageEvolution. Oxford U. Press. 235-254.

Citation Format(s)

A motor differentiation model for liquid substitutions: English /r/ variants in normal and disordered acquisition. / Gick, Bryan; Bernhardt, Barbara; Bacsfalvi, Penelope et al.
2007. Paper presented at Ultrafest IV, New York, United States.

Research output: Conference Papers (RGC: 31A, 31B, 32, 33)32_Refereed conference paper (without host publication)peer-review