Utilizing the ventriloquism-effect to investigate audio-visual binding.
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.
Bischoff
M
M
Bender Institute of Neuroimaging and Department of Clinical and Physiological Psychology, Justus-Liebig-University, Giessen, Germany. matthias.bischoff@psychol.uni-giessen.de
Walter
B
B
Blecker
C R
CR
Morgen
K
K
Vaitl
D
D
Sammer
G
G
D000161:Acoustic Stimulation / Q000379:methods; D000328:Adult; D000704:Analysis of Variance; D001307:Auditory Perception / Q000502:physiology*; D015982:Bias; D001931:Brain Mapping; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D010100:Oxygen / Q000097:blood; D010775:Photic Stimulation / Q000379:methods; D011930:Reaction Time / Q000502:physiology; D013997:Time Factors; D014796:Visual Perception / Q000502:physiology*
D010100:Oxygen