Barrow Neurological Institute, St Joseph's Hospital and Medical Center, Phoenix, AZ, USA.
Department of Electrical and Computer Engineering, Duke University, Durham, NC, USA.
J Physiol. 2019 Nov;597(21):5195-5229. doi: 10.1113/JP278108. Epub 2019 Oct 6.
Vision plays a crucial role in guiding locomotion in complex environments, but the coordination between gaze and stride is not well understood. The coordination of gaze shifts, fixations, constant gaze and slow gaze with strides in cats walking on different surfaces were examined. It was found that gaze behaviours are coordinated with strides even when walking on a flat surface in the complete darkness, occurring in a sequential order during different phases of the stride. During walking on complex surfaces, gaze behaviours are typically more tightly coordinated with strides, particularly at faster speeds, only slightly shifting in phase. These findings indicate that the coordination of gaze behaviours with strides is not vision-driven, but is a part of the whole body locomotion synergy; the visual environment and locomotor task modulate it. The results may be relevant to developing diagnostic tools and rehabilitation approaches for patients with locomotor deficits.
Vision plays a crucial role in guiding locomotion in complex environments. However, the coordination between the gaze and stride is not well understood. We investigated this coordination in cats walking on a flat surface in darkness or light, along a horizontal ladder and on a pathway with small stones. We recorded vertical and horizontal eye movements and 3-D head movement, and calculated where gaze intersected the walkway. The coordination of gaze shifts away from the animal, gaze shifts toward, fixations, constant gaze, and slow gaze with strides was investigated. We found that even during walking on the flat surface in the darkness, all gaze behaviours were coordinated with strides. Gaze shifts and slow gaze toward started in the beginning of each forelimb's swing and ended in its second half. Fixations peaked throughout the beginning and middle of swing. Gaze shifts away began throughout the second half of swing of each forelimb and ended when both forelimbs were in stance. Constant gaze and slow gaze away occurred in the beginning of stance. However, not every behaviour occurred during every stride. Light had a small effect. The ladder and stones typically increased the coordination and caused gaze behaviours to occur 3% earlier in the cycle. At faster speeds, the coordination was often tighter and some gaze behaviours occurred 2-16% later in the cycle. The findings indicate that the coordination of gaze with strides is not vision-driven, but is a part of the whole body locomotion synergy; the visual environment and locomotor task modulate it.
视觉在复杂环境中的导向运动中起着至关重要的作用，但眼球运动和步伐之间的协调关系还没有得到很好的理解。本研究旨在观察猫在不同表面上行走时眼球运动的扫视、注视、固视和慢扫视与步伐之间的协调关系。结果发现，即使在完全黑暗的平坦表面上行走，眼球运动行为也与步伐协调一致，在步伐的不同阶段按顺序发生。在复杂表面上行走时，眼球运动行为通常与步伐更加紧密地协调，尤其是在较快的速度下，相位仅略有变化。这些发现表明，眼球运动行为与步伐的协调不是由视觉驱动的，而是整个身体运动协同的一部分；视觉环境和运动任务对其进行调节。研究结果可能与为运动障碍患者开发诊断工具和康复方法有关。
视觉在复杂环境中的导向运动中起着至关重要的作用。然而，眼球运动和步伐之间的协调关系还没有得到很好的理解。我们研究了猫在黑暗或光照下的平坦表面、水平梯级和小石径上行走时的协调关系。我们记录了垂直和水平眼球运动以及 3-D 头部运动，并计算了注视点与步道的交点。我们研究了眼球向远处扫视、向目标扫视、注视、固视和慢扫视与步伐之间的协调关系。结果发现，即使在黑暗中行走在平坦表面上，所有的眼球运动行为也都与步伐协调一致。向远处扫视和慢扫视开始于每个前肢摆动的开始，并在其后半部分结束。注视在摆动的开始和中间达到峰值。向远处的扫视开始于每个前肢摆动的后半部分，并在两个前肢都处于支撑阶段时结束。固视和向远处的慢扫视发生在支撑阶段的开始。然而，并不是每个行为都在每个步伐中发生。光照只有很小的影响。梯级和石头通常会增加协调，使眼球运动行为在周期中提前 3%发生。在较快的速度下，协调通常更紧密，一些眼球运动行为在周期中晚 2-16%发生。研究结果表明，眼球运动与步伐的协调不是由视觉驱动的，而是整个身体运动协同的一部分；视觉环境和运动任务对其进行调节。
