The multisensory integration capabilities of superior colliculus (SC) neurons are normally acquired during early postnatal life and adapted to the environment in which they will be used. Recent evidence shows that they can even be acquired in adulthood, and require neither consciousness nor any of the reinforcement contingencies generally associated with learning. This process is believed to be based on Hebbian mechanisms, whereby the temporal coupling of multiple sensory inputs initiates development of a means of integrating their information. This predicts that co-activation of those input channels is sufficient to induce multisensory integration capabilities regardless of the specific spatiotemporal properties of the initiating stimuli. However, one might expect that the stimuli to be integrated should be consonant with the functional role of the neurons involved. For the SC, this would involve stimuli that can be localized. Experience with a non-localizable cue in one modality (e.g., ambient sound) and a discrete stimulus in another (e.g., a light flash) should not be sufficient for this purpose. Indeed, experiments with cats reared in omnidirectional sound (effectively masking discrete auditory events) reveal that the simple co-activation of two sensory input channels is not sufficient for this purpose. The data suggest that experience with the kinds of cross-modal events that facilitate the role of the SC in detecting, locating, and orienting to localized external events is a guiding factor in this maturational process. Supported by NIH grants NS 036916 and EY016716