Modulations of `late' event-related brain potentials in humans by dynamic audiovisual speech stimuli

authors

  • Lebib R
  • Papo D
  • Douiri A
  • Bode S
  • Dowens Mg
  • Baudonniere Pm

document type

ART

abstract

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. (C) 2004 Elsevier Ireland Ltd. All rights reserved.

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