The past decade has seen great progress in the measurement of evoked potentials in man; a steady increase in our understanding of their charac­ teristics, their origins and their usefulness; and a growing application in the field of clinical diagnosis. The topic is a truly multidisciplinary one. Important research contributions have been made by workers of many different backgrounds and clinical applications span the specialities. This book represents a revised and updated version of the work originally presented at the international evoked potential symposium held in Nottingham 4-6 1978. The Nottingham Symposium provided a forum for a state-of-the-art discussion amongst workers from many different disciplines and from many different countries. For each major topic in the field an expert review set the scene for discussion of current research presentations. This format is retained in the book: the chapters in Part A provide the context in which the research presented in Part B is set. The task of selecting material for this book, from the wealth of interesting work presented at the Symposium, was undertaken by a selection committee of distinguished authors who were the chairmen for the specialized sessions. To Dr F. W. Campbell, Professor S. J. Crews, Mr W. P. R. Gibson, Professor G. F. A. Harding, Dr D. A. Jeffreys, Dr D. G. Small, Professor H. Spekreijse, Dr A. Starr, Dr A. R. D. Thornton and Professor L. H. van der Tweel, I record my thanks.