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Multisensory Perception and Biological Motion. Ayse Pinar Saygin, Margarita Sarri, Jon Driver Institute of Cognitive Neuroscience BUCNI Project Presentation Nov 29 2007. Background.
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Multisensory Perception and Biological Motion Ayse Pinar Saygin, Margarita Sarri, Jon Driver Institute of Cognitive Neuroscience BUCNI Project Presentation Nov 29 2007
Background Recent interest in audio-visual multisensory interplay (e.g. Noesselt/Driver, 2007, J Neurosci; STS for matching temporal patterns with flashes and beeps) Little known about multisensory processing for more complex or ecological stimuli (other than speech)
Background Recent interest in audio-visual multisensory interplay (e.g. Noesselt/Driver, 2007, J Neurosci; STS for matching temporal patterns with flashes and beeps) Little known about multisensory processing for more complex or ecological stimuli (other than speech) Biological motion - activates STS Seen movements often accompanied by sounds We recently showed behavioural effects of heard ‘footsteps’ during dot-walker perception (Saygin, Driver & de Sa, Psychological Science, in press) Single cells in the STS that are responsive to biological motion show increased activity when corresponding sounds are present
Design fMRI of audio-visual interplay in biological motion Visual Stimuli: dot-jogger or same dots scrambled Auditory Stimuli: “footstep” sounds in or out of synch with ‘foot’ dots Visual noise: Principle of inverse effectiveness Demo.
Proposal N=16 subjects, 6 runs of ~ 8 minutes • Event related, whole brain coverage, TR=2200 ms. • To be analyzed with SPM Conditions Biological/Scrambled (plus noise dots) Matching/Mismatching sound Task: Decide whether jogger is present Unisensory (Biological, Scrambled, Just Sound, Fixation) • Predictions: Expected in the STS, possibly IFG, unisensory areas • AV_Congruent > AV_Incongruent • AV > A, V with Congruent sound • Possibly AV < A, V with Incongruent sound • Interaction with Visual Stimulus type: Multisensory effect greater for Biological compared with Scrambled