Interaction between the oculomotor and postural systems during a dual-task: compensatory reductions in head sway following visually-induced postural perturbations promote the production of accurate double-step saccades in standing human adults

Humans routinely scan their environment for useful information using saccadic eye movements and/or coordinated movements of the eyes and other body segments such the head and the torso. Most previous eye movement studies were conducted with seated subject and showed that single saccades and sequences of saccades (e.g. double-step saccades) made to briefly flashed stimuli were equally accurate and precise. As one can easily appreciate, most gaze shifts performed daily by a given person are not produced from a seated position, but rather from a standing position either as subject perform an action from an upright stance or as they walk from one place to another. In the experiments presented here, we developed a new dual-task paradigm in order to study the interaction between the gaze control system and the postural system. Healthy adults (n = 12) were required to both maintain balance and produce accurate single-step and double-step eye saccades from a standing position. Visually-induced ...

人类日常会通过扫视眼动（saccadic eye movement）以及眼与头部、躯干等身体节段的协同运动，对周遭环境开展有效信息扫描。既往绝大多数眼动研究均以坐姿被试为实验对象，结果显示，针对短暂闪现刺激完成的单次扫视及扫视序列（如双步扫视（double-step saccades）），其准确性与精确性无显著差异。不难发现，个体日常完成的绝大多数视线转移并非源自坐姿，而是来自直立站姿：既可以是被试以直立姿态完成动作时，也可以是被试从一处步行至另一处时。在本文呈现的实验中，我们开发了一种全新的双任务范式（dual-task paradigm），用以探究视线控制系统（gaze control system）与姿势控制系统（postural system）之间的交互机制。本研究招募12名健康成年被试，要求其在直立站姿下同时维持身体平衡，并完成精准的单次眼扫视与双步眼扫视任务。视觉诱发的……