1. Bioelectromagnetics Research Laboratory, Department of Rehabilitation Medicine, University of Washington School of Medicine, Seattle 98195
2. Department of Bioengineering, Moore School of Engineering, University of Pennsylvania, Philadelphia 19104
3. Department of Neurological Sciences, University of California, La Jolla 92093
4. Neuropsychology and Behavioral Radiology Laboratories, USVA Medical Center, Kansas City, Missouri 64128