The arbitrary linkage of sensory cues to actions and goals represents one of the most-flexible capabilities in the behavioral repertoire of mammals. This ability has been termed 'conditional motor learning', 'conditional discrimination' or, more recently, 'arbitrary visuomotor mapping'. Unlike other forms of visuomotor guidance, in arbitrary mapping the location of the sensory cue lacks any systematic spatial relationship with the action or its goal. Recent work has identified much of the neural network that underlies this behavior. It consists of parts of the frontal cortex, hippocampal system and basal ganglia, each of which has neurons whose activity undergoes systematic evolution during learning.