Recent technological developments have made popular home-based systems to present visual stimuli in 3D and sounds from multiple sources. These systems generate a rich and multisensory percept of external space, with an augmented sense of scene-structure and enhanced sound-localization. We investigated the neural correlates of 3D-surround cinematography using stereoscopy and a multi-speakers system during fMRI. Subjects watched a commercial 3D movie presented in four, factorially-organized conditions: 3D-surround, 3D-mono, 2D-surround or 2D-mono (blocks of 26−57 s). They were then asked to evaluate the “sense of presence” of short clips extracted from the movie, again presented in the 4 conditions. The imaging results showed a main effect of 3D viewing in LOC, V3A and SPL. The main effect of surround sound activated the auditory cortex, while an interaction between vision and audition was observed in the MTG, inferior-anterior to the auditory cortex. In MTG maximal activation was found in the 2D-surrond condition. This region may perform the analysis of complex auditory scenes, and more so in the absence of redundant visuo-spatial depth information. The appraisal results revealed that 3D-vision was the main factor triggering an enhanced sense of presence. Consistent with this, the presence scores were associated with activity in lateral and dorsal occipital areas, but also with visual scene-related areas in the ventral occipito-temporal cortex. These data show that the perception of 3D-surround stimuli relies on an extensive set of visual and auditory areas, implicating these regions in the processing of the complex multisensory signals that characterize our everyday-life experience.

fMRI; cinematography; stereoscopic depth; surround sound; sense of presence