1. School of Mechanical and Aerospace Engineering, Nanyang Technological University, Singapore
2. EVENT Lab, Facultat de Psicologia, Universitat de Barcelona, Spain
3. EVENT Lab, Facultat de Psicologia, Universitat de Barcelona, Spain and Institució Catalana de Recerca, i Estudis Avançats (ICREA) and Department of Computer Science, University College London
4. Institute of Automatic Control Engineering, Technische Universität München, D-80290 Munich, Germany