Laurence Harris is professor of psychology at York University, Ontario, Canada. An expert in the brain's processing of information from multiple senses, especially regarding self-motion and orientation in normal and unusual environments, particularly space; his research involves work on the International Space Station and in environments simulated using virtual reality. Michael Jenkin is professor of computer science and engineering at York University, Ontario, Canada. His research interests include perception and guidance for autonomous robotic systems, and the development and analysis of virtual reality systems. In 2005 he was the recipient of the CIPPRS/ACTIRF award for research excellence and service to the Canadian Computer and Robot Vision research community.