Multistability in perception: Binding sensory modalities, an overview

International audience; This paper introduces the basic phenomenon of multistability, which occurs when a single physical stimulus produces alternations between different subjective percepts. The phenomenon was first discovered when different images were presented to the two eyes; the perceived image was dominated at any one time by the image presented to one eye, but the percept "flipped" unpredictably, an effect called binocular rivalry. Multistability was later discovered to occur for a wide range of visual stimuli, including those involving apparent motion, and to occur for auditory, tactile and olfactory stimuli. The key features of stimuli leading to multistability are: (i) they have more than one plausible perceptual organisation; (ii) these organisations are not compatible with each other. Most cases of multistability are based on competition in selecting and binding stimulus information. Hence, multistability can be used as a method for studying the binding process in various perceptual modalities. The binding issue is considered here in three different directions: binding sensory information into perceptual scenes for defining perceptual objects in each modality; binding sensory inputs across modalities for addressing questions about multisensory perceptual organisation in the brain; and binding our knowledge of neural processing in various sensory modalities to let emerge new questions, new methods and new models. The paper concludes with an outline of the papers in this issue and with some thoughts about open directions and avenues for further research.