Utilizing the ventriloquism-effect to investigate audio-visual binding.
Bischoff, M. a,*; Walter, B. a; Blecker, C. R. a; Morgen, K. b; Vaitl, D. a; Sammer, G. a
[Article]
Neuropsychologia.
45(3):578-586, 2007.
(Format: HTML, PDF)
Audio-visual binding - as subset of crossmodal integration - describes the combination of information across both these senses to the subjective unified perception of a bound object.
We investigated audio-visual binding by using the ventriloquism-effect (localization of a sound is biased towards and by a simultaneous visual stimulus) to act as an indicator for perceived binding. Simple visual and auditory stimuli were presented synchronously or asynchronously. fMRI was recorded during task performance (n = 19 subjects) in order to reveal activation in areas discussed to be involved in multisensory processing in the literature.
Contrasting trials with reported ventriloquism-effect versus the no-binding condition revealed activation in the insula, superior temporal sulcus and parieto-occipital sulcus. Implementing the ventriloquism-effect allows us to relate these activations to consciousness-related processes, which probably are different from stimulus-driven multisensory integration in subcortical areas.
(C) 2007Elsevier, Inc.