1. Centre for Innovative Applications of Internet and Multimedia Technologies, City University of Hong Kong, Hong Kong, People’s Republic of China
2. Department of Language and Cognition, University College London, London, UK
3. Department of Paediatrics, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong, People’s Republic of China
4. Department of Computing, The Hong Kong Polytechnic University, Hong Kong, People’s Republic of China