van der Veer Albert H, Longo Matthew R, Alsmith Adrian J T, Wong Hong Yu, Mohler Betty J
Max Planck Institute for Biological Cybernetics, Tübingen, Germany.
International Max Planck Research School for Cognitive and Systems Neuroscience, University of Tübingen, Tübingen, Germany.
Front Robot AI. 2019 May 8;6:33. doi: 10.3389/frobt.2019.00033. eCollection 2019.
It is currently not fully understood where people precisely locate themselves in their bodies, particularly in virtual reality. To investigate this, we asked participants to point directly at themselves and to several of their body parts with a virtual pointer, in two virtual reality (VR) setups, a VR headset and a large-screen immersive display (LSID). There was a difference in distance error in pointing to body parts depending on VR setup. Participants pointed relatively accurately to many of their body parts (i.e., eyes, nose, chin, shoulders, and waist). However, in both VR setups when pointing to the feet and the knees they pointed too low, and for the top of the head too high (to larger extents in the VR headset). Taking these distortions into account, the locations found for pointing to self were considered in terms of perceived bodies, based on where the participants had pointed to their body parts in the two VR setups. Pointing to self in terms of the perceived body was mostly to the face, the upper followed by the lower, as well as some to the torso regions. There was no significant overall effect of VR condition for pointing to self in terms of the perceived body (but there was a significant effect of VR if only the physical body (as measured) was considered). In a paper-and-pencil task outside of VR, performed by pointing on a picture of a simple body outline (body template task), participants pointed most to the upper torso. Possible explanations for the differences between pointing to self in the VR setups and the body template task are discussed. The main finding of this study is that the VR setup influences where people point to their body parts, but not to themselves, when perceived and not physical body parts are considered.
目前人们尚未完全清楚自己在身体中的精确位置，尤其是在虚拟现实环境中。为了对此进行研究，我们要求参与者在两种虚拟现实（VR）设置中，即VR头戴式设备和大屏幕沉浸式显示器（LSID）中，用虚拟指针直接指向自己以及自己的几个身体部位。根据VR设置的不同，指向身体部位时的距离误差存在差异。参与者能够相对准确地指向许多身体部位（如眼睛、鼻子、下巴、肩膀和腰部）。然而，在两种VR设置中，当指向脚和膝盖时，他们指得过低，而指向头顶时又指得过高（在VR头戴式设备中的偏差更大）。考虑到这些偏差，根据参与者在两种VR设置中指向身体部位的位置，从感知身体的角度来考虑指向自己的位置。从感知身体的角度指向自己时，大多指向脸部，其次是上半身，也有一些指向躯干区域。就感知身体而言，VR条件对指向自己并没有显著的总体影响（但如果仅考虑（测量得到的）物理身体，则VR有显著影响）。在VR之外的纸笔任务中，通过指向简单身体轮廓的图片（身体模板任务），参与者大多指向躯干上部。本文讨论了在VR设置中指向自己与身体模板任务之间差异的可能解释。本研究的主要发现是，当考虑的是感知身体部位而非物理身体部位时，VR设置会影响人们指向身体部位的位置，但不会影响指向自己的位置。
