Ataxia following exposure to a virtual environment

Background: Virtual environment (VE) technology has many promising applicat ions in a variety of areas that may likely lead to widespread use as techno logy progresses and cost decreases. Recent research has demonstrated that s imulator sickness, a well-established effect of simulator exposure, can occ ur with VE exposure as well. Because ataxia (postural unsteadiness) is know n to occur following simulator exposure, it might also occur following VE e xposure. Simulator sickness and after-effects, such as ataxia, pose severe safety risks and raise serious liability questions. Method: A PC-based VE s ystem was used to investigate the occurrence of ataxic decrements in postur al stability following a 20-min exposure to a commercially available game. There were 20 male and 20 female undergraduate students who served as parti cipants. Postural stability was assessed using a sensitive, reliable measur e of stance involving the velocity of head movement sway along the y-axis. Data on the occurrence of simulator sickness were also collected. Based on findings in other simulators, ataxia was hypothesized to occur. Results: At axic decrements in postural stability were not found although simulator sic kness did occur. Conclusions: Several possible factors possibly involved in the lack of ataxia were considered: statistical power; aspects of the post ural test; participants' VE-adaptation, exposure time, and immersion positi on; and the task performed. Ataxia may not be associated with short exposur es to VEs for asks which are not highly dynamic and individuals who are not experienced with the system.