Ataxia following exposure to a virtual environment

Virtual environment (VE) technology has many promising applications in a variety of areas that may likely lead to widespread use as technology progresses and cost decreases. Recent research has demonstrated that simulator sickness, a well-established effect of simulator exposure, can occur with VE exposure as well. Because ataxia (postural unsteadiness) is known to occur following simulator exposure, it might also occur following VE exposure. Simulator sickness and after-effects, such as ataxia, pose severe safety risks and raise serious liability questions.

A PC-based VE system was used to investigate the occurrence of ataxic decrements in postural stability following a 20-min exposure to a commercially available game. There were 20 male and 20 female undergraduate students who served as participants. Postural stability was assessed using a sensitive, reliable measure 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.

Ataxic decrements in postural stability were not found although simulator sickness did occur.

Several possible factors possibly involved in the lack of ataxia were considered: statistical power; aspects of the postural test; participants' VE adaptation, exposure time, and immersion position; and the task performed. Ataxia may not be associated with short exposures to VEs for tasks which are not highly dynamic and individuals who are not experienced with the system.