Sensory organization of the superior colliculus in cat and monkey.

The sensory representations and response properties of neurons in the multisensory layers of the superior colliculus (SC) of the cat and monkey are strikingly similar. In both species, significant numbers of unimodal visual, auditory, and somatosensory neurons are intermixed, and share modality-specific stimulus selectivities. In addition, these neurons have receptive fields that are organized in similar map-like representations, with the different maps sharing the same axes and, thus, exhibiting a characteristic cross-modality correspondence. Both species also have a large contingent of multisensory neurons that synthesize information from different sensory modalities using a common set of spatial, temporal, and physical principles. These findings suggest that, despite differences in the ontogeny and behavioral repertoires of cat and monkey, there is a substantial conservation in the organization and functional properties of SC neurons. Apparently, these functional features of the SC are adaptive in a wide variety of ecological situations.