title: Is audiovisual integration subserved by the superior colliculus in humans?
abstract: The brain effectively integrates multisensory information to enhance perception. For example, audiovisual stimuli typically yield faster responses than isolated unimodal ones (redundant signal effect, RSE). Here, we show that the audiovisual RSE is likely subserved by a neural site of integration (neural coactivation), rather than by an independent-channels mechanism such as race models. This neural site is probably the superior colliculus (SC), because an RSE explainable by neural coactivation does not occur with purple or blue stimuli, which are invisible to the SC; such an RSE only occurs for spatially and temporally coincident audiovisual stimuli, in strict adherence with the multisensory responses in the SC of the cat. These data suggest that audiovisual integration in humans occurs very early during sensory processing, in the SC.
authors.affiliation: Psychology Department, University of Milano-Bicocca, Milano, Italy. angelo.maravita@unimib.it
authors.forename: Angelo
authors.initials: A
authors.lastname: Maravita
authors.forename: Nadia
authors.initials: N
authors.lastname: Bolognini
authors.forename: Emanuela
authors.initials: E
authors.lastname: Bricolo
authors.forename: Carlo A
authors.initials: CA
authors.lastname: Marzi
authors.forename: Silvia
authors.initials: S
authors.lastname: Savazzi
mesh_terms: D000161:Acoustic Stimulation; D000328:Adult; D001307:Auditory Perception / Q000502:physiology*; D003116:Color; D006801:Humans; D010775:Photic Stimulation; D011930:Reaction Time / Q000502:physiology; D013477:Superior Colliculi / Q000473:pathology*; D014796:Visual Perception / Q000502:physiology*