Functional grouping of the cortico-pretectal projection.

The ascendency of the cerebral cortex in mammals naturally raises questions about the role of the archetypal subcortical centers we share in common with other phyla. Here we report a situation in which an ancient oculomotor control center, the nucleus of the optic tract, is not so much dominated by the cerebral cortex as served by it. We suggest that the organization of cortical output to subcortical centers may be helpful in understanding the function of the cerebral cortex.