Centre for Computational Neuroscience and Robotics, University of Sussex, Falmer, Brighton, United Kingdom. d.bush@sussex.ac.uk|Centre for Computational Neuroscience and Robotics, University of Sussex, Falmer, Brighton, United Kingdom. d.bush@sussex.ac.uk|Centre for Computational Neuroscience and Robotics, University of Sussex, Falmer, Brighton, United Kingdom. d.bush@sussex.ac.uk|Centre for Computational Neuroscience and Robotics, University of Sussex, Falmer, Brighton, United Kingdom. d.bush@sussex.ac.uk