Audio-visual integration effect in lateral occipital cortex during an object recognition task: An interference pilot study

Recent neuroimaging data support the hypothesis of a multisensory interplay at low-level sensory-specific cortex. We used an on-line interference approach by rTMS to investigate the role of the left lateral occipital cortex (LOC) in audio-visual (AV) object recognition process. Fifteen healthy volunteers performed a visual identification task of degraded pictures presented alone or simultaneously to coherent or non-coherent sounds. Focal 10-Hz rTMS at an intensity of 100% resting motor threshold was delivered simultaneously to the picture. Two blocks of 60 pictures were randomly displayed in two different experimental conditions: rTMS of the left LOC and over Cz. rTMS of the left LOC produced a worsening of the accuracy compared to rTMS over Cz specifically in the coherent AV condition. These data support the view that audio-visual interaction effect may occur at early stage of recognition processing.