Timothy J. Gawne has a B.S. in electrical engineering from M.I.T., and a PhD in physiology from U.S.U.H.S. He worked as an engineer at the Digital Equipment Corporation, and then moved into biomedical research. Currently he as an associate professor in the department of Vision Sciences in the University of Alabama at Birmingham (UAB). His primary interests are in how information is processed in the visual parts of the brain. This book arose out of a course "Electronics for Biologists" that he has taught, and is an effort to concisely present the fundamental concepts of electronics needed for a biologist, without requiring an engineering background.