Effects of low video latency between visual information and physical sensation in immersive environments

Abstract

This study aims to investigate the impact on the user's performance when there is latency between the user's physical input to the system and the visual feedback. We developed a video latency control system to film the user's hand movements and control the latency when displaying the video (The standard deviation is 0.38 ms). The minimum latency of the system is 4.3 ms, hence this enables us to investigate the performance for unknown low latency ranges. Using this system, we conducted experiments wherein 20 subjects performed a pointing task based on Fitts' law to clarify the effect of video latency, particularly for low latency. Experimental results showed that when the latency is over 24.3 ms, the user performance begins to decrease. This result will be applied to determine a standard limit for video latency in interactive video devices.