title: The speech focus position effect on jaw-finger coordination in a pointing task.
abstract: OBJECTIVE
  This article investigates jaw-finger coordination in a task involving pointing to a target while naming it with a CVCV (e.g., /papa/) versus CVCV (e.g., /papa/) word. According to the authors' working hypothesis, the pointing apex (gesture extremum) would be synchronized with the apex of the jaw-opening gesture corresponding to the stressed syllable.
  
  
  METHODS
  Jaw and finger motions were recorded using Optotrak (Northern Digital, Waterloo, Ontario, Canada). The effects of stress position on jaw-finger coordination were tested across different target positions (near vs. far) and different consonants in the target word (/t/ vs. /p/). Twenty native Portuguese Brazilian speakers participated in the experiment (all conditions).
  
  
  RESULTS
  Jaw response starts earlier, and finger-target alignment period is longer for CVCV words than for CVCV ones. The apex of the jaw-opening gesture for the stressed syllable appears synchronized with the onset of the finger-target alignment period (corresponding to the pointing apex) for CVCV words and with the offset of that period for CVCV words.
  
  
  CONCLUSIONS
  For both stress conditions, the stressed syllable occurs within the finger-target alignment period because of tight finger-jaw coordination. This result is interpreted as evidence for an anchoring of the speech deictic site (part of speech that shows) in the pointing gesture.
authors.affiliation: GIPSA Laboratory, Department of Speech and Cognition, Grenoble, France. amelie@motion.psych.mcgill.ca
authors.forename: Amélie
authors.initials: A
authors.lastname: Rochet-Capellan
authors.forename: Rafael
authors.initials: R
authors.lastname: Laboissière
authors.forename: Arturo
authors.initials: A
authors.lastname: Galván
authors.forename: Jean-Luc
authors.initials: JL
authors.lastname: Schwartz
mesh_terms: D000293:Adolescent; D000328:Adult; D005260:Female; D005385:Fingers / Q000502:physiology*; D006801:Humans; D007568:Jaw / Q000502:physiology*; D008297:Male; D009068:Movement / Q000502:physiology*; D010700:Phonetics; D011597:Psychomotor Performance / Q000502:physiology*; D013060:Speech / Q000502:physiology*; D013997:Time Factors