COGNITIVE NEUROSCIENCE: The time-course of intermodal binding between seeing and hearing affective information

Intermodal binding between affective information that is seen as well as heard triggers a mandatory process of audiovisual integration. In order to track the time course of this audiovisual binding, event related brain potentials were recorded while subjects saw facial expression and concurrently heard auditory fragment. The results suggest that the combination of the two inputs is early in time (110 ms post-stimulus) and translates as a speci®c enhancement in amplitude of the auditory N1 component. These ®ndings are compatible with previous functional neuroimaging results of audiovisual speech showing strong audiovisual interactions in auditory cortex in the form of magnetic response ampli®cations, as well as with electrophysiological studies demonstrating early audiovisual interactions (before 200 ms post-stimulus). Moreover, our results show that the informational content present in the two modalities plays a crucial role in triggering the intermodal binding process. NeuroReport 11:1329±1333 & 2000 Lippincott Williams & Wilkins.