Navigation in space--the role of the macaque ventral intraparietal area.

Goal-directed self-motion through space is anything but a trivial task. What we take for granted in everyday life requires the complex interplay of different sensory and motor systems. On the sensory side most importantly a target of interest has to be localized relative to one's own position in space. On the motor side the most critical step in neural processing is to define and perform a movement towards the target as well as the avoidance of obstacles. Furthermore, the multisensory (visual, tactile and auditory) motion signals as induced by one's own movement have to be identified and differentiated from the real motion of visual, tactile or auditory objects in the outside world. In a number of experimental studies performed in recent years we and others have functionally characterized a subregion within monkey posterior parietal cortex (PPC) that appears to be well suited to contribute to such multisensory encoding of spatial and motion information. In this review I will summarize the most important experimental findings on the functional properties of this very region in monkey PPC, i.e. the ventral intraparietal area.