Framsticks

The involvement of the mirror neuron system (MNS) in both imitation and action understanding has been firmly established. Various authors have claimed that the MNS's function in facilitating imitation builds upon its role in action understanding and is a phylogenetically later development. We argue that this hypothesis lacks sufficient evidence and present support for the reverse: the phylogenetically primary function of the MNS is imitation and the MNS could have evolved in response to a selective pressure for imitative behavior. This hypothesis was tested using evolutionary robotics simulation techniques. The simulation was conducted with embodied and embedded agents with a lifetime-adapting neural network for which the learning parameters were evolutionarily optimized. The agents had to perform an imitation task. Analysis of the resulting controller revealed artificial neurons showing clear mirror characteristics, suggesting that, indeed, mirror neurons evolve due to a selective pressure for imitative behavior.