Modeling parietal-premotor interactions in primate control of grasping.

Visual information is processed in the posterior parietal cortex for the hypothesized purpose of extracting a variety of affordances for the generation of motor behavior. The term affordance is used to mean that visual cues are mapped directly to parameters that are relevant for motor interaction. In this paper, we present the FARS model of the cortical involvement in grasping, a model which focuses on the interaction between anterior intra-parietal area (AIP) and premotor area F5. The model represents the role of other intra-parietal areas, working in concert with inferotemporal cortex and F5, to provide AIP with a full range of information from which affordances may be derived. The model also suggests how task information and other constraints may resolve the action opportunities provided by multiple affordances. Our model demonstrates not only that posterior parietal cortex is a network of interacting subsystems, but also that it functions through a pattern of "cooperative computation" with a multiplicity of other brain regions. Finally, through the use of several novel tasks, the model allows us to make specific predictions regarding neural firing patterns at both the single unit and population levels, which aids in our further understanding of information encoding in these brain regions.