There are many situations in which what we see (hear) is strongly affected by what we hear (see). For instance, in the classic ventriloquism effect, the perceived location of a sound (ventriloquist's speech) is displaced towards the location of a concomitant visual event (puppet). In spite of the implausibility of the situation, our perception is resilient to our conscious knowledge that the puppet cannot speak. Conversely in noisy environments, seeing the interlocutor's face enhances the intelligibility of what is said. Thus, multisensory integration can improve, impair or create perception. How does the brain integrate information from different senses? Under which circumstances does multisensory integration benefit / impair /create perception? This project aims to clarify the brain mechanisms underlying the automatic integration of multisensory information. The major steps in this project are: (i) Psychophysical paradigms will be designed to specifically address automaticity and predictability in multisensory perception. (ii) Healthy population will be tested with combined magneto- and electro-encephalography (MEG-EEG) in order to functionally determine the neural dynamics of multisensory integration. (iii) Healthy population will be tested with functional magnetic resonance imaging (fMRI) in order to determine the precise anatomical structures underlying automatic multisensory integration. (iv) Patient populations (neglect and schizophrenic populations, in particular) will be tested using the paradigms developed in (i). An emphasis on the benefit of multisensory perception for neuro- and cognitive-rehabilitation will be made in adapting those paradigms. (v) Children will be tested using paradigms developed in (i) in order to comprehend how early in life multisensory interactions take effect and how learning skills such as reading could benefit from multisensory integration.