School of Physical and Occupational Therapy, McGill University, Montreal, QC, Canada.
CRIR-Feil and Oberfeld Research Center, Jewish Rehabilitation Hospital, CISSS-Laval, 3205 Place Alton-Goldbloom, Laval, QC, H7V 1R2, Canada.
Exp Brain Res. 2022 Oct;240(10):2633-2645. doi: 10.1007/s00221-022-06427-2. Epub 2022 Aug 18.
We investigated gaze behaviour and collision avoidance strategies in 16 healthy young individuals walking towards a goal while exposed to virtual pedestrians (VRPs) approaching from different directions (left, middle, right). This locomotor task and an auditory-based cognitive task were performed under single and dual-task conditions. Longer gaze fixation durations were observed on the approaching vs. other VRPs, with longer fixations devoted to the upper trunk and head compared to other body segments. Compared to other pedestrian approaches, the middle pedestrian received longer fixations and elicited faster walking speeds, larger onset distances of trajectory devitation and smaller obstacle clearances. Gaze and locomotor behaviours were similar between single and dual-task conditions but dual-task costs were observed for the cognitive task. The longer gaze fixations on approaching vs. other pedestrians suggest that enhanced visual attention is devoted to pedestrians posing a greater risk of collision. Likewise, longer gaze fixations for the middle pedestrians may be due to the greater collision risk entailed by this condition, and/or to the fact that this pedestrian was positioned in front of the end goal. Longer fixations on approaching VRPs' trunk and head may serve the purpose of anticipating their walking trajectory. Finally, the dual-task effects that were limited to the cognitive task suggest that healthy young adults prioritize the locomotor task and associated acquisition of visual information. The healthy patterns of visuomotor behaviour characterized in this study will serve as a basis for comparison to further understand defective collision avoidance strategies in patient populations.
我们研究了 16 名健康的年轻人在走向目标的过程中的注视行为和避碰策略，同时他们还会遇到从不同方向（左、中、右）接近的虚拟行人（VRP）。这项运动任务和基于听觉的认知任务在单任务和双任务条件下进行。与其他 VRP 相比，参与者在接近的 VRP 上会有更长的注视持续时间，与其他身体部位相比，他们会将更多的注意力集中在上半身和头部。与其他行人接近的情况相比，中间的行人会获得更长的注视时间，并且行走速度更快，轨迹偏离的起始距离更大，障碍物清除距离更小。在单任务和双任务条件下，注视和运动行为相似，但认知任务存在双任务成本。与其他行人相比，参与者对接近的行人有更长的注视时间，这表明他们对更有可能发生碰撞的行人给予了更多的视觉关注。同样，对于中间的行人给予更长的注视时间可能是由于这种情况下存在更大的碰撞风险，或者是因为这个行人位于终点目标的前面。对接近的 VRP 躯干和头部的更长注视时间可能有助于预测他们的行走轨迹。最后，仅限于认知任务的双重任务效应表明，健康的年轻人会优先考虑运动任务和相关的视觉信息获取。本研究中描述的健康视动行为模式将作为进一步理解患者群体中缺陷避碰策略的基础。
