Effects of image scale and system time delay on simulator sickness within head-coupled virtual environments

Area of Science:

• Human-Computer Interaction
• Virtual Reality Safety
• Sensory Perception

Background:

• Virtual environments can induce simulator sickness due to conflicting visual-vestibular cues.
• Understanding these effects is crucial for virtual reality (VR) system safety and user experience.

Purpose of the Study:

• To investigate how varying virtual image scale factors and system time delays impact simulator sickness.
• To assess the relationship between visual-vestibular conflict and reported sickness symptoms.

Main Methods:

• Two experiments exposed participants to a 50-min virtual environment using a head-coupled interface.
• Experiment 1 manipulated image scale factors (0.5, 1.0, 2.0). Experiment 2 added time delays (125, 250 ms).
• Simulator sickness was measured via self-reports during exposure, questionnaires, and head movement data.

Main Results:

• Significantly higher simulator sickness reports occurred with minification (0.5) and magnification (2.0) image scale factors compared to the neutral (1.0) condition.
• Simulator sickness levels did not significantly vary with introduced system time delays.
• No substantial increase in sickness was observed with time delays above 48 ms.

Conclusions:

• Visual-vestibular mismatch, particularly altered image scale, is a primary driver of simulator sickness in VR.
• System time delay appears to be a less significant factor in simulator sickness compared to visual scaling.
• Findings inform the design of safer and more comfortable virtual environment systems for training, simulation, and entertainment.