Department of Psychology, Graduate School of Humanities and Social Sciences, Kumamoto University, 2-40-1 Kurokami, Kumamoto City, 860-8555, Japan.
Sci Rep. 2022 May 18;12(1):8330. doi: 10.1038/s41598-022-12022-w.
This study investigated age-related change in visuo-proprioceptive processing in the perceived body position using mirror hand/foot illusions, focusing on its temporal characteristics, its dependency on body parts, and its association with older adults' fall risk. Either immediately or 15 s after the exposure to the mirror-induced inconsistency of visuo-proprioceptive signals regarding the right hand or foot position, participants performed a reaching task using the unseen, illusion-affected hand or foot. Results showed clear age group differences. Specifically, older adults exhibited larger reaching errors than younger adults in the hand condition, and after the 15 s delay in the foot condition. Further, the reaching errors were constant across time for older adults but decreased after the delay in young adults, regardless of the tested body part. Particularly, older adults' risk of falling, which was assessed by the timed up-and-go test, was negatively correlated with the reduction of reaching error across time. This suggests that older adults, especially those with a high risk of falling, face difficulties in appropriately processing visual and proprioceptive information for body perception in accordance with their external environment.
本研究通过镜像手/脚错觉，考察了与年龄相关的视本体感觉加工在感知身体位置方面的变化，重点关注其时间特征、对身体部位的依赖性以及与老年人跌倒风险的关系。在接触到右手或脚位置的视本体感觉信号的镜像不一致后，参与者立即或 15 秒后，使用看不见的、受错觉影响的手或脚执行一个伸手任务。结果显示出明显的年龄组差异。具体来说，与年轻人相比，老年人在手的条件下，以及在脚的条件下延迟 15 秒后，表现出更大的伸手错误。此外，老年人的伸手错误在时间上是恒定的，而年轻人则在延迟后减少，无论测试的身体部位如何。特别是，老年人的跌倒风险（通过计时站起和行走测试评估）与伸手错误随时间的减少呈负相关。这表明，老年人，尤其是那些跌倒风险较高的老年人，在根据外部环境适当处理身体感知的视觉和本体感觉信息方面存在困难。
