Multisensory integration in superior colliculus (SC) neurons: a computational study.

Neurons in the cat superior colliculus (SC) can integrate information from different sensory modalities and enhance their responses to cross-modal stimuli in spatiotemporal coincidence. These SC neurons receive unisensory inputs from many subcortical and cortical areas, but inputs from association cortex are critical. They are essential for the development of multisensory integration and for its expression during adulthood. The mechanisms underlying multisensory integration can be clarified with the use of mathematical models and computer simulations, and in recent years, we proposed a neural network model of the SC that can reproduce the different experimental results such as multisensory enhancement, and cross-modal and within-modal suppression. However, the model was unable to account for the maturation of multisensory integration or for its loss in adulthood during cortical deactivation. The objective of this work is to present an improved model which is able to explain these physiological features of multisensory integration and which incorporates recent neurological observations concerning the convergence patterns from cortical and subcortical sources and the impact of specific receptors.