Abstract
The research on vection during treadmill locomotion appears contradictory. For example, Onimaru (2010) reported that walking forwards on a treadmill impaired the vection induced by expanding flow, whereas Seno et al (2011) appeared to find a vection enhancement in these conditions. These previous studies both examined smooth self-motion displays, despite the fact that jittering displays have consistently been shown to improve vection in seated observers. We simulated constant velocity expanding and contracting optic flow displays, in which subjects physical movements were either updated as additional display jitter (synchronised head-display motion) or not updated into the self-motion display. We also varied the display/treadmill forward speed – these could be simulated at either 4 km/hr or 5 km/hr. Subjects viewed displays in real-time while walking on a treadmill or on the spot and as passive playbacks while stationary. Subjects rated their perceived strength of vection in depth using a joystick (compared to a standard reference stimulus). We found vection impairments for both expanding and contracting optic flow displays and similar impairments when subjects actively walked on the spot. Despite finding a general vection impairment for active walking, faster display/treadmill forward speeds and synchronised head-display jitter improved vection. It was concluded that vection impairments while walking appear to be independent of the display’s simulated direction and the nature of one’s walking activity.
Meeting abstract presented at VSS 2012