28 juin 2011
Catherine Best présentera "Infant detection of articulator congruency between audio and video presentations of native and nonnative consonant contrasts"
- Intervenant : Catherine Best
- Laboratoire : MARCS Auditory Laboratories, University of Western Sydney
- Date prévue : 28 juin 2011 à 13h00
- Lieu : salle D28, 1er étage, bâtiment BSHM
- Titre : Infant detection of articulator congruency between audio and video presentations of native and nonnative consonant contrasts
- Abstract :
Infants are sensitive to audio-visual relations in speech, and this changes as a result of language experience. Three theoretical accounts have been posited. Learned-association accounts hold that the visual patterns of talking faces become linked to fundamentally auditory representations of speech via experience with co-occurring audio and visual patterns (e.g., Kuhl & Meltzoff, 1982; Massaro, 1998). By the perceptual narrowing account, young infants show universal sensitivity to intersensory relations in multimodal stimuli, but this narrows down to just the audiovisual correspondences in native speech (Pons et al., 2009). Our amodal articulatory account posits infants detect information about actions of the speech articulators irrespective of modality (Best, 1994), and can easily distinguish among actions of different articulators (between-organ) but actions by a single articulator (within-organ) become difficult unless supported by language-specific experience (Best & McRoberts, 2003; Goldstein & Fowler, 2003; Tyler et al., 2008). These accounts can be compared by examining infants' perception of cross-modal congruency in native versus nonnative between-organ contrasts. If audio-visual associations are learned, older infants should perceive congruency better than younger infants for native but neither age should detect congruency for nonnative contrasts. If perceptual narrowing occurs, congruency should be detected by younger infants for both contrasts, but by older infants only for the native contrast. The amodal articulatory account predicts sensitivity to articulator congruency in both native and nonnative between-organ contrasts at both ages, but older infants should display effects of increased familiarity with the native contrast.
Three studies examined 4- versus 11-month-olds' sensitivity to articulatory organ congruency between audio-only habituation and subsequent silent-video presentations of between-organ contrasts (lips vs. tongue tip closure) from: 1. the native language (English /pa/-/ta/) and two nonnative language contrasts (2. Tigrinya ejective /p'a/-/t'a/; 3. !Xoo bilabial-dental click syllables) using a conditioned-fixation procedure with audio habituation followed by silent-video faces. The 4-month-olds showed a visual preference for articulator-congruency for both the native and nonnative Tigrinya consonants, but it was reliable only when the first video test trial was congruent with the habituated audio syllable (Figure 1). For the the native contrast, 11-month-olds showed a strong congruency preference across test trials if the first trial was congruent, but a fleeting incongruity preference for the first test trial alone if it was incongruent. However, for the Tigrinya contrast they showed just a strong incongruency preference (Figure 2). For the nonnative !Xoo clicks, however, both ages' preferences were the reverse of their performance on Tigrinya. Consisttent with the amodal articulatory account, performance differed strikingly between 4- and 11- month-olds, indicating that language experience has a significant impact on perception of articulatory relations between heard and seen consonants in both native and nonnative speech.