Prey-catching and predator avoidance 1: maps and schemas

We model the construction of motor actions through the interaction of different motor schemas via a process of competition and cooperation wherein there is no need for a unique schema to win the competition (although that might well be the result) since two or more schemas may simultaneously be active and cooperate to yield a more complicated motor pattern. Based on lesion data, our model is structured on the principles of segregation of coordinate systems and participation of maps intermediate between sensory and motor schemas. The motor schemas are driven by specific internal maps which between them constitute a distributed internal representation of the world. These maps collectively provide the transition from topographically-coded sensory information to frequency-coded inputs to the diverse motor schemas that drive muscle activity. As a challenge to further comparative analysis of the prey-catching and predator-avoidance systems, we argue that the Positional Heading Map hypothesis, (that the heading map codes the position of the object) should be rejected in favor of the Motor Heading Map hypothesis. This holds that each system has a separate projection pathway that converges in a different way onto the heading map, coding the required motor response, which has a single connection pattern to those motor schemas common to both systems.