Effects of Reading Text on an Optical See-Through Head-Mounted Display During Treadmill Walking in a Virtual Environment

Abstract

This study evaluated the effects of reading text on an optical see-through head-mounted display during treadmill walking in a virtual environment. Thirty participants were recruited to perform Chinese reading tasks by reading six types of text layouts in two polarity settings. A virtual environment was displayed on a projection screen to simulate a walking situation in which obstacles were encountered. High- and low-density obstacles were applied. Objective measures included reading performance, gait variability, and the error count of obstacles. The subjective measures were the situational awareness rating technique (SART) and NASA-Task Load Index (NASA-TLX) scores. The results indicated that font size and polarity affected the gait variability, reading performance, situational awareness, and mental workload ratings. The obstacle density affects gait variability and situation awareness rating. The layout with 32-point text and positive polarity yielded faster reading speed, better subjective ratings, and less variability in minimum foot clearance.