Department of Mechanical & Aerospace Engineering, Princeton University, Princeton, New Jersey, United States of America, Department of Physics, University of California, Santa Barbara, Santa Barbara, California, United States of America.|Department of Physics, University of California, Santa Barbara, Santa Barbara, California, United States of America.|Department of Bioengineering, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America, Department of Electrical and Systems Engineering, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America.|University of Oxford Medical Sciences Division, John Radcliffe Hospital, Headington, Oxford, United Kingdom, Behavioural and Clinical Neuroscience Institute and Department of Psychiatry, University of Cambridge, Cambridge, United Kingdom.|Department of Psychological and Brain Sciences, University of California, Santa Barbara, Santa Barbara, California, United States of America.|Department of Psychological and Brain Sciences, University of California, Santa Barbara, Santa Barbara, California, United States of America.|Department of Physics, University of California, Santa Barbara, Santa Barbara, California, United States of America.