Dynamique temporelle du liage dans la fusion de la parole audiovisuelle (Temporal dynamics of binding in audiovisual speech fusion) [in French]

________________________________________________________________________________________________________ Temporal dynamics of binding in audiovisual speech fusion The McGurk effect demonstrates the phenomenon of audiovisual fusion: a sound "ba" mounted on a video "ga" is often perceived as "da". In a previous work we showed that audiovisual fusion might be modulated by a precedent binding process (Nahorna et al., 2011, 2012). In these experiments a McGurk stimulus was preceded by an audiovisual coherent or incoherent context (sound corresponding or not to the video) and we observed a decrease of the McGurk effect in the incoherent context case. This effect occurs for contexts varying from 3 to 10 seconds, with no significant effect of the context duration in this range. In the present work we study shorter context durations. The results show that one syllable is sufficient to unbind the auditory and visual streams and to produce a strong decrease in the McGurk effect. MOTS-CLES : Effet McGurk, liage, fusion multisensorielle, perception de la parole audiovisuelle, analyse de scène audiovisuelle.