1ASTAR-NUS Clinical Imaging Research Centre, Department of Electrical and Computer Engineering, Singapore Institute for Neurotechnology and Memory Networks Program, National University of Singapore, Singapore, Singapore, 2Department of Neurology, Massachusetts General Hospital/Harvard Medical School, Charlestown, MA, United States, 3Martinos Center for Biomedical Imaging, Massachusetts General Hospital/Harvard Medical School, Charlestown, MA, United States, 4Computer Science and Artificial Intelligence Laboratory, Massachusetts Institute of Technology, Cambridge, MA, United States, 5Centre for Cognitive Neuroscience, Duke-NUS Graduate Medical School, Singapore, Singapore