A Psychophysical Examination of Swinging Rooms, Cylindrical Virtual Reality Setups, and Characteristic Trajectories Douglas W. Cunningham * Hans-G¨ unther Nusseck † Harald Teufel ‡ Christian Wallraven § Heinrich H. B¨ ulthoff ¶ Max Planck Institute for Biological Cybernetics T¨ ubingen, Germany Figure 1: A 3D depiction of the Virtual Reality setup used in the experiments. ABSTRACT Virtual Reality (VR) is increasingly being used in industry, medicine, entertainment, education, and research. It is generally critical that the VR setups produce behavior that closely resembles real world behavior. One part of any task is the ability to con- trol our posture. Since postural control is well studied in the real world and is known to be strongly influenced by visual informa- tion, it is an ideal metric for examining the behavioral fidelity of VR setups. Moreover, VR-based experiments on postural control can provide fundamental new insights into human perception and cognition. Here, we employ the “swinging room paradigm” to vali- date a specific VR setup. Furthermore, we systematically examined a larger range of room oscillations than previously studied in any single setup. We also introduce several new methods and analyses that were specifically designed to optimize the detection of syn- chronous swinging between the observer and the virtual room. The results show that the VR setup has a very high behavioral fidelity and that increases in swinging room amplitude continue to produce increases in body sway even at very large room displacements (+/- 80 cm). Finally, the combination of new methods proved to be a very robust, reliable, and sensitive way of measuring body sway. * e-mail:douglas.cunningham@tuebingen.mpg.de † e-mail:hg.nusseck@tuebingen.mpg.de ‡ e-mail:harald.teufel@tuebingen.mpg.de § e-mail:christian.wallraven@tuebingen.mpg.de ¶ e-mail:heinrich.buelthoff@tuebingen.mpg.de CR Categories: I.3.7 [Computer Graphics]: Three-Dimensional Graphics and Realism—Virtual Reality; J.4 [Social and Behavioral Sciences]: Psychology—; Keywords: applied perception, postural stability, swinging room, human-computer interface, computer graphics, 1 I NTRODUCTION Virtual Reality is increasingly being used to train individuals for real world tasks, to rehabilitate patients, and to learn more about human perception and performance [7, 13, 19]. For these applica- tions, it is critical that the fidelity of the Virtual Reality (VR) setup, including the Virtual Environment (VE), be high enough to pro- duce behavior similar to that found in the real world. A number of researchers have recently shown that traditional psychophysical methodology can be successfully used to measure the behavioral and perceptual fidelity of computer graphics algorithms (see, e.g., [1, 13, 14, 17]). These experiments not only provide information about the strengths and weaknesses of the computer graphics al- gorithms, they also provide fundamental new insights into human perception and cognition. An important, and often overlooked, prerequisite for any task, especially in an interactive application in VR, is that we must first be able to attain and then maintain the particular pose required by the task. If a VR setup does not support or elicit normal postural control, it is very doubtful that it can support higher-order phenom- ena such as immersion or proper spatial orientation. Although at first glance postural control seems to be an easy task, it is in fact a very complex process. The complexity of postural control can easily be seen, for example, by observing a child who is just learning to stand upright[19]. More concretely, postural con- 111 IEEE Virtual Reality 2006 March 25 - 29, Alexandria, Virginia, USA 1-4244-0224-7/06/$20.00 ©2006 IEEE Proceedings of the IEEE Virtual Reality Conference (VR’06) 1087-8270/06 $20.00 © 2006 IEEE Authorized licensed use limited to: IEEE Xplore. Downloaded on April 17, 2009 at 06:08 from IEEE Xplore. Restrictions apply.