Researchers in recent decades have elucidated signal transduction in the retina and the function of the visual cortex. The highly flexible nature of neural circuits in the visual cortex especially during the critical period has been an interesting subject for studying neural plasticity and development. Recent advances in the visual neurosciences of the vertebrate retina and the visual cortex were discussed during the 12th Keio International Symposium for Life Science and Medicine, meeting jointly with Vision Forum 2002. Contributions to the symposium collected in this volume reflect the...