Experiments in animal models have shown that running increases neuronal activity in early visual areas in light as well as in darkness. This suggests that visual processing is influenced by locomotion independent of visual input. Combining mobile electroencephalography, motion- and eye-tracking, we investigated the influence of overground free walking on cortical alpha activity (~10 Hz) and eye movements in healthy humans. Alpha activity has been considered a valuable marker of inhibition of sensory processing and shown to negatively correlate with neuronal firing rates. We found that walking led to a decrease in alpha activity over occipital cortex compared to standing. This decrease was present during walking in darkness as well as during light. Importantly, eye movements could not explain the change in alpha activity. Nevertheless, we found that walking and eye related movements were linked. While the blink rate increased with increasing walking speed independent of light or darkness, saccade rate was only significantly linked to walking speed in the light. Pupil size, on the other hand, was larger during darkness than during light, but only showed a modulation by walking in darkness. Analyzing the effect of walking with respect to the stride cycle, we further found that blinks and saccades preferentially occurred during the double support phase of walking. Alpha power, as shown previously, was lower during the swing phase than during the double support phase. We however could exclude the possibility that the alpha modulation was introduced by a walking movement induced change in electrode impedance. Overall, our work indicates that the human visual system is influenced by the current locomotion state of the body. This influence affects eye movement pattern as well as neuronal activity in sensory areas and might form part of an implicit strategy to optimally extract sensory information during locomotion.

中文翻译：

---

地上行走会降低人类的阿尔法活动并引起眼球运动

动物模型实验表明，跑步会增加早期视觉区域的神经元活动，无论是在光线还是在黑暗中。这表明视觉处理受独立于视觉输入的运动的影响。结合移动脑电图、运动和眼动追踪，我们研究了地上自由行走对健康人类皮质 α 活动（~10 Hz）和眼球运动的影响。Alpha 活动被认为是抑制感觉处理的重要标志，并显示出与神经元放电率呈负相关。我们发现，与站立相比，步行会导致枕叶皮层的 α 活动减少。这种减少在黑暗中行走以及在光明中都存在。重要的是，眼球运动无法解释 alpha 活动的变化。尽管如此，我们发现行走和眼睛相关的运动是相关联的。虽然眨眼率随着步行速度的增加而增加，而与光或暗无关，但跳视率仅与光中的步行速度显着相关。另一方面，在黑暗中瞳孔的大小比在光照时要大，但只有在黑暗中行走时才会显示出调制。分析步行对步幅周期的影响，我们进一步发现在步行的双支撑阶段优先发生眨眼和扫视。如前所述，阿尔法力量在摆动阶段低于双支持阶段。然而，我们可以排除 alpha 调制是由步行运动引起的电极阻抗变化引入的可能性。全面的，我们的工作表明，人类视觉系统受到身体当前运动状态的影响。这种影响影响眼球运动模式以及感觉区域的神经元活动，并可能构成在运动过程中最佳提取感觉信息的隐式策略的一部分。