Modulations of 'late' event-related brain potentials in humans by dynamic audiovisual speech stimuli.
Lipreading reliably improve speech perception during face-to-face conversation. Within the range of good dubbing, however, adults tolerate some audiovisual (AV) discrepancies and lipreading, then, can give rise to confusion. We used event-related brain potentials (ERPs) to study the perceptual strategies governing the intermodal processing of dynamic and bimodal speech stimuli, either congruently dubbed or not. Electrophysiological analyses revealed that non-coherent audiovisual dubbings modulated in amplitude an endogenous ERP component, the N300, we compared to a 'N400-like effect' reflecting the difficulty to integrate these conflicting pieces of information. This result adds further support for the existence of a cerebral system underlying 'integrative processes' lato sensu. Further studies should take advantage of this 'N400-like effect' with AV speech stimuli to open new perspectives in the domain of psycholinguistics.
Lebib
Riadh
R
Neuroscience Cognitive et Imagerie Cérébrale, LENA-CNRS UPR 640, Groupe Hospitalier Pitié-Salpêtrière, 47, bd de l'Hôpital, 75651 Paris, Cedex 13, France. rlebib@ull.es
Papo
David
D
Douiri
Abdel
A
de Bode
Stella
S
Gillon Dowens
Margaret
M
Baudonnière
Pierre-Marie
PM
D000161:Acoustic Stimulation / Q000379:methods*; D000328:Adult; D000704:Analysis of Variance; D005071:Evoked Potentials / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D010775:Photic Stimulation / Q000379:methods*; D013060:Speech / Q000502:physiology*; D013067:Speech Perception / Q000502:physiology*