Parallel processing of multisensory information concerning self-motion.

Cats trained to stand on a platform exhibit postural responses to dynamic tilting that appear to be based on an internal reference model of body geometry and the environment rather than directly on sensory inputs, as in a classical reflex chain. The data presented show an independent control of global variables of limb geometry, the length and the orientation, resulting from a parallel processing of multisensory inputs into separate central representations of body tilt. Limb length and orientation changes have completely different response dynamics and can be decoupled by appropriate manipulation of sensory information about self-motion.