1. Department of Bioengineering, Stanford University, Stanford, CA 94305, USA.
2. Neuroscience Program, Stanford University, Stanford, CA 94305, USA.
3. Department of Electrical Engineering, Stanford University, Stanford, CA 94305, USA.
4. Department of Statistics, Stanford University, Stanford, CA 94305, USA.
5. Department of Psychiatry and Behavioral Sciences, Stanford University, Stanford, CA 94305, USA.