title: Atypical audiovisual speech integration in infants at risk for autism.
abstract: The language difficulties often seen in individuals with autism might stem from an inability to integrate audiovisual information, a skill important for language development. We investigated whether 9-month-old siblings of older children with autism, who are at an increased risk of developing autism, are able to integrate audiovisual speech cues. We used an eye-tracker to record where infants looked when shown a screen displaying two faces of the same model, where one face is articulating/ba/and the other/ga/, with one face congruent with the syllable sound being presented simultaneously, the other face incongruent. This method was successful in showing that infants at low risk can integrate audiovisual speech: they looked for the same amount of time at the mouths in both the fusible visual/ga/- audio/ba/and the congruent visual/ba/- audio/ba/displays, indicating that the auditory and visual streams fuse into a McGurk-type of syllabic percept in the incongruent condition. It also showed that low-risk infants could perceive a mismatch between auditory and visual cues: they looked longer at the mouth in the mismatched, non-fusible visual/ba/- audio/ga/display compared with the congruent visual/ga/- audio/ga/display, demonstrating that they perceive an uncommon, and therefore interesting, speech-like percept when looking at the incongruent mouth (repeated ANOVA: displays x fusion/mismatch conditions interaction: F(1,16) = 17.153, p = 0.001). The looking behaviour of high-risk infants did not differ according to the type of display, suggesting difficulties in matching auditory and visual information (repeated ANOVA, displays x conditions interaction: F(1,25) = 0.09, p = 0.767), in contrast to low-risk infants (repeated ANOVA: displays x conditions x low/high-risk groups interaction: F(1,41) = 4.466, p = 0.041). In some cases this reduced ability might lead to the poor communication skills characteristic of autism.
authors.affiliation: Centre for Brain and Cognitive Development, Department of Psychological Science, Birkbeck, University of London, London, United Kingdom. jeanne_guiraud@hotmail.com
authors.forename: Jeanne A
authors.initials: JA
authors.lastname: Guiraud
authors.forename: Przemyslaw
authors.initials: P
authors.lastname: Tomalski
authors.forename: Elena
authors.initials: E
authors.lastname: Kushnerenko
authors.forename: Helena
authors.initials: H
authors.lastname: Ribeiro
authors.forename: Kim
authors.initials: K
authors.lastname: Davies
authors.forename: Tony
authors.initials: T
authors.lastname: Charman
authors.forename: Mayada
authors.initials: M
authors.lastname: Elsabbagh
authors.forename: Mark H
authors.initials: MH
authors.lastname: Johnson
mesh_terms: D001321:Autistic Disorder / Q000453:epidemiology* / Q000503:physiopathology; D006801:Humans; D007223:Infant; D012307:Risk Factors; D013060:Speech; D014785:Vision, Ocular