Abstract
Past research demonstrated that distance perception is less accurate in virtual reality environments (Loomis & Knapp, 2003) than in the real world. In real life, actions improve accuracy in reaching judgements (Bootsma, 1989; Oudejans, Michaels, Bakker, & Dolné, 1996). Avatars aid in accuracy involving distance judgements in virtual reality (Mohler, Creem-Regehr, Thompson, & Bülthoff, 2010; Lin, Rieser, & Bodenheimer, 2015). The present study sought to test if action in conjunction with an avatar's presence will improve reachability judgement in VR. A virtual ball was placed at eye level at different egocentric distances. The task was to perceive whether the ball is within reach. Condition 1 was perception-only, where the participant was not allowed to move nor could see their arms. Condition 2 was perception with nonvisible action, where the participant could move their real arm to reach but could not see an avatar of the arm. Condition 3 was perception with visible action, where the participant could move and see a virtual hand that corresponded to the actual arm movement. By employing both perception and action Condition 3 was expected to have the highest accuracy and fastest response time due to its superior ecological validity, followed by Condition 2 and Condition 1. There were 25 participants ran per condition, for 75 participants total. Participants reported distances as reachable that were beyond their arm length by about 15% in the avatar condition and the proprioceptive condition, followed by the perception-only condition which was the most accurate (around 5% overestimation). Response times were comparable for distances within reach, but got longer in Conditions 2 and 3 when the ball was out of reach. Our results point to the lack of expected haptic feedback as a critical variable that may have caused distortion in the avatar action condition.