1. Department of Neurosurgery and Hansen Experimental Physics Laboratory, Stanford University, Stanford, California;
2. Departments of Electrical Engineering and Computer Science, Stanford University, Stanford, California;
3. Systems Neurobiology Laboratories, Salk Institute for Biological Studies, La Jolla, California;
4. Faculty of Physics and Applied Computer Science, AGH University of Science and Technology, Krakow, Poland; and
5. Santa Cruz Institute for Particle Physics, University of California, Santa Cruz, Santa Cruz, California