An embodied model of action selection mechanisms in the vertebrate brain

In previous research we have demonstrated a computational model of the intrinsic circuitry of the vertebrate basal ganglia based on the proposal that these central brain structures play an important role in action selection. The current work embeds this model within the control architecture of a Khepera mobile robot allowing action selection between multiple behaviors styled on some of the home cage activities of a laboratory rat. Our results demonstrate appropriate and clean switching by the embodied basal ganglia model between wall-following, search, 'food'-pickup, corner-finding, and ‘food’-deposit behaviors. The robot can be seen to select appropriate actions for different circumstances and to generate integrated sequences of behavior. The normal function of the basal ganglia is sensitive to fluctuations in the level of the neurotransmitter dopamine. The effects on the robot model of varying the simulated dopamine level show interesting similarities to those observed in animals. This research demonstrates that the proposed functional model of the basal ganglia is sufficient for effective action selection within a fully specified behavioral control architecture.