He examines cognitive processes using cross-linguistic, neuropsychological and brain imaging methods. His research can be applied to understanding problems in clinical neuropsychology including bilingual aphasia, dementia and reading difficulties. He is Chair in Communication Science at the University of Hong Kong and Director of the Communication Science Laboratory at HKU, where he has been since 2010. Prior 2010, he was a Reader in Experimental Psychology at the University of Sussex for ten years.