Abstract: Visual attention has long been an important topic in psychology and cognitive science. Recently, results from visual attention research (Haber et al. 2001; Myszkowski et al. 2001) are being adopted by computer graphics research. Due to speed limitations, there has been a movement to use a perception-based rendering approach where the rendering process itself takes into account where the user is most likely looking (Haber et al. 2001). Examples include trying to achieve real-time global illumination by concentrating the global illumination calculation only in parts of the scene that are salient (Myszkowski 2002). Video games have achieved a high degree of popularity because of such advances in computer graphics. These techniques are also important because they have enabled game environments to be used in applications such as health therapy and training.