1 Department of Electrical and Computer Engineering, Duke University, Durham, NC, USA. Electronic address: jinshui.zhang@duke.edu.
2 Department of Psychiatry and Behavioral Sciences, Duke University, Durham, NC, USA; Department of Electrical and Computer Engineering, Duke University, Durham, NC, USA; Department of Biomedical Engineering, Duke University, Durham, NC, USA; Department of Neurosurgery, Duke University, Durham, NC, USA; Duke Institute for Brain Sciences, Duke University, Durham, NC, USA.
3 Department of Electrical and Computer Engineering, Duke University, Durham, NC, USA; Department of Psychiatry and Behavioral Sciences, Duke University, Durham, NC, USA; Department of Neurosurgery, Duke University, Durham, NC, USA; Duke Institute for Brain Sciences, Duke University, Durham, NC, USA; Department of Engineering, University of Cambridge, Cambridgeshire, UK. Electronic address: smg84@cam.ac.uk.