Sensory Fusion

Multisensory integration is known to occur in many regions of the brain, and involves several aspects of our daily life; however, the underlying neural mechanisms are still insufficiently understood. This chapter presents two mathematical models of multisensory integration, inspired by real neurophysiological systems. The first considers the integration of visual and auditory stimuli, as it occurs in the Superior Colliculus (a subcortical region involved in orienting eyes and head toward external events). The second model considers the integration of tactile stimuli and visual stimuli close to the body to form the perception of the peripersonal space (the space immediately around our body, within which we can interact with the external world). Although devoted to two specific problems, the mechanisms delineated in the models (lateral inhibition and excitation, non-linear neuron characteristics, recurrent connections, competition) may govern more generally the fusion of senses in the brain. The models, besides improving our comprehension of brain function, may drive future neurophysiological experiments and provide valuable ideas to build artificial systems devoted to sensory fusion.