Graduate Program for Neuroscience, Boston University, Boston, Massachusetts, United States of America.|Department of Mathematics & Statistics, Boston University, Boston, Massachusetts, United States of America.|Department of Psychological and Brain Sciences, Boston University, Boston, Massachusetts, United States of America.|Department of Neuroscience, Brown University, Providence, Rhode Island, United States of America.|Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, United States of America.|Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, United States of America.|Department of Mathematics & Statistics, Boston University, Boston, Massachusetts, United States of America.