Topographic organization in the brain: searching for general principles.

The neurons comprising many cortical areas have long been known to be arranged topographically such that nearby neurons have receptive fields at nearby locations in the world. Although this type of organization may be universal in primary sensory and motor cortex, in this review we demonstrate that associative cortical areas may not represent the external world in a complete and continuous fashion. After reviewing evidence for novel principles of topographic organization in macaque lateral intraparietal area (LIP) - one of the most-studied associative areas in the parietal cortex - we explore the implications of these new principles for brain function.