1. A brain-based device comprising: a) a mechanism enabling movement of the brain-based device in a real-world environment; b) a simulated nervous system, being interactive with the real-world environment, for controlling said mechanism to cause the brain-based device to move in the real-world environment; and c) said simulated nervous system including a model of the cerebellum having synapses which are eligible for plasticity only after a given time interval to enable the model to predict motor control of said mechanism.