Sensorimotor control of complex locomotor tasks in ecological environments

社区步行需要避免与周围障碍物相撞的技能。众所周知，行人的避碰策略受人的感觉运动功能和干扰物的方向/速度等因素的影响。然而，(I)干扰者的性别和情感步态模式(社会认知因素)和(Ii)观察者的性别(生物因素)在多大程度上相互作用并对形成碰撞避免策略做出贡献仍是未知的。在这个项目中，将通过基于虚拟现实的运动(项目1和2)和神经成像项目(项目3和4)来研究这些因素如何影响碰撞避免。研究的目的是：(1)调查通过外表和步态动作感知的干扰者的性别对碰撞避免策略的影响，以及它可能与参与者的性别相互作用；(2)调查情绪步态对碰撞避免策略的影响，以及性别(参与者)和性别(干扰者)的调节作用；(3)揭示性别知觉的神经机制及其由于外表和生物运动信息而调节的作用；(4)确定情绪步态感知的神经机制，以及性别(参与者)和性别(干扰者)的调节效应。健康的年轻男性和女性将参与其中。在项目1中，他们将在配备了眼睛追踪器的头盔显示器上观看的虚拟环境(VE)中行走，同时暴露在虚拟行人(VRP)中，虚拟行人(VRP)根据他们的步态模式(女性、男性)和身体外观(女性、男性或中性)显示性别差异。在项目2中，参与者将接触到显示不同情感步态模式(高兴、愤怒、悲伤、速度匹配的中性条件)的男性和女性VRP。在这两个项目中，运动(清除障碍、开始偏离弹道等)研究人员将比较不同性别和/或情绪状况以及不同性别群体之间的凝视结果(例如，对VRP身体部分的注视百分比)。在项目3和4中，参与者坐着并暴露在屏幕上投射的VE时，将用脑磁图记录他们的大脑活动。在项目3中，参与者将在类似于项目1的条件下区分VRP的性别。在项目4中，他们将区分表现不同情感步态的男性和女性VRP的情绪。事件相关电位(峰值、潜伏期)和连贯性(连通性分析)在涉及形式、运动和情绪处理的关键大脑区域将在条件和组之间进行比较。研究结果将为视觉运动和大脑机制提供关于性别、性别和情绪在行人互动中的调节作用的视角。它们将进一步支持生态有效的虚拟现实场景的开发，同时为探索复杂行走任务在整个生命周期内的控制变化提供比较基础。

Community walking requires the skills to avoid collisions with surrounding obstacles. Collision avoidance strategies amongst pedestrians are known to be modulated by one's sensorimotor function and by factors such as the direction/speed of interferers. However, the extent to which (i) the gender and emotional gait pattern of an interferer (socio-cognitive factors) and (ii) the sex of the observer (biological factor) interact and contribute in shaping collision avoidance strategies remains unknown. In this program, how these factors impact on collision avoidance will be investigated through virtual reality-based locomotor (Project 1 & 2) and neuroimaging projects (Project 3 & 4). Objectives are to: (1) Investigate the influence of the interferer's gender, as perceived via physical appearance vs. gait movements, on collision avoidance strategies, and its possible interaction with the participants' sex; (2) Investigate the impact of emotional gait on collision avoidance strategies, and the modulatory effects of sex (participants) and gender (interferers); (3) Uncover the neural mechanisms involved in gender perception and their modulation due to appearance and biological motion information; (4) Determine the neural mechanisms underpinning the perception of emotional gait, and the modulatory effect of sex (participants) and gender (interferers). Healthy young males and females will participate. In Project 1, they will walk in a virtual environment (VE) viewed in a head mounted display equipped with an eye tracker, while exposed to virtual pedestrians (VRPs) displaying variations in gender as per their gait pattern (female, male) and physical appearance (female, male or neutral). In Project 2, participants will be exposed to male and female VRPs displaying different emotional gait patterns (happy, angry, sad, speed-matched neutral conditions). In both projects, locomotor (obstacle clearance, onset of trajectory deviation, etc.) and gaze outcomes (e.g., % fixation on body segments of VRP) will be compared across gender and/or emotion conditions and between sex groups. In Projects 3 & 4, participants' brain activity will be recorded with magnetoencephalography while seated and exposed to a VE projected on a screen. In Project 3, participants will discriminate the gender of VRPs in conditions similar to Project 1. In Project 4, they will discriminate the emotion of male and female VRPs displaying different emotional gaits. Event-related potentials (peak, latency) and coherence (connectivity analysis) in key brain areas involved in form, motion and emotion processing will be compared between conditions and groups. Results will provide visuomotor and brain mechanism perspectives on the modulatory role of sex, gender and emotions in pedestrian interactions. They will further support the development of ecologically-valid VR scenarios while providing a comparison basis for exploring changes in the control of complex walking tasks across the lifespan.