Sensory Motor Responses in Virtual Environments: Studying the Effects of Image Latencies for Target-directed Hand Movement

Image latencies occur when a virtual environment (VE) responds to hand movements of its operator. A study has been conducted to investigate the effects of, and interactions among, hand movement related image latencies, target distance, and target width on discrete manual control tasks in a VE. In the presence of latencies, completion times of hand movement tasks have been found to obey Fitts' law. Significant interactions were found between the effect of latency and target width, but not between the effect of latency and target distance. Results suggest that, in the presence of hand movement-related image latencies, the effects of target width and target distance should not be analyzed as a combined single effect of `Index-of-Difficulty'.