1. Department of Artificial Intelligence, Donders Institute for Brain, Cognition, and Behaviour, Radboud University, Nijmegen, The Netherlands
2. Perceptual Robotics Laboratory at the IIM Institute, Department of Excellence in Robotics and A.I., Scuola Superiore Sant'Anna, Pisa, Italy
3. Department of Bioengineering, Department of Electrical and Systems Engineering, Department of Physics and Astronomy, the Department of Psychiatry, and Department of Neurology, University of Pennsylvania, Philadelphia, PA, USA
4. Department of Mechanical Engineering, University of California, Riverside, CA, USA