Campos Jennifer L, El-Khechen Richandi Graziella, Coahran Marge, Fraser Lindsey E, Taati Babak, Keshavarz Behrang
Department of Psychology, University of Toronto, Toronto, ON, Canada.
KITE Research Institute - Toronto Rehabilitation Institute, University Health Network, Toronto, ON, Canada.
J Rehabil Assist Technol Eng. 2021 Dec 7;8:20556683211059389. doi: 10.1177/20556683211059389. eCollection 2021 Jan-Dec.
Embodiment involves experiencing ownership over our body and localizing it in space and is informed by multiple senses (visual, proprioceptive and tactile). Evidence suggests that embodiment and multisensory integration may change with older age. The Virtual Hand Illusion (VHI) has been used to investigate multisensory contributions to embodiment, but has never been evaluated in older adults. Spatio-temporal factors unique to virtual environments may differentially affect the embodied perceptions of older and younger adults.
Twenty-one younger (18-35 years) and 19 older (65+ years) adults completed the VHI paradigm. Body localization was measured at baseline and again, with subjective ownership ratings, following synchronous and asynchronous visual-tactile interactions.
Higher ownership ratings were observed in the synchronous relative to the asynchronous condition, but no effects on localization/drift were found. No age differences were observed. Localization accuracy was biased in both age groups when the virtual hand was aligned with the real hand, indicating a visual mislocalization of the virtual hand.
No age-related differences in the VHI were observed. Mislocalization of the hand in VR occurred for both groups, even when congruent and aligned; however, tactile feedback reduced localization biases. Our results expand the current understanding of age-related changes in multisensory embodiment within virtual environments.
具身认知涉及对自身身体的所有权体验以及在空间中对其进行定位，并且受到多种感官（视觉、本体感觉和触觉）的影响。有证据表明，具身认知和多感官整合可能会随着年龄增长而发生变化。虚拟手错觉（VHI）已被用于研究多感官对具身认知的贡献，但从未在老年人中进行过评估。虚拟环境特有的时空因素可能会对老年人和年轻人的具身认知产生不同的影响。
21名年轻人（18 - 35岁）和19名老年人（65岁及以上）完成了虚拟手错觉范式。在基线时以及在同步和异步视觉 - 触觉交互后，通过主观所有权评分再次测量身体定位。
与异步条件相比，同步条件下观察到更高的所有权评分，但未发现对定位/漂移有影响。未观察到年龄差异。当虚拟手与真实手对齐时，两个年龄组的定位准确性都存在偏差，表明虚拟手存在视觉定位错误。
未观察到虚拟手错觉中与年龄相关的差异。两组在虚拟现实中手部都出现了定位错误，即使在一致和对齐的情况下也是如此；然而，触觉反馈减少了定位偏差。我们的结果扩展了当前对虚拟环境中多感官具身认知与年龄相关变化的理解。
