Physical Therapy Department, Ben-Gurion University of the Negev, Be'er-Sheva, Israel.
Negev Lab, Translational Neurorehabilitation Laboratory, Adi-Negev, Nahalat Eran, Ofakim, Israel.
Sci Rep. 2022 Jan 11;12(1):513. doi: 10.1038/s41598-021-04540-w.
Downward gazing is often observed when walking requires guidance. This gaze behavior is thought to promote walking stability through anticipatory stepping control. This study is part of an ongoing effort to investigate whether downward gazing also serves to enhance postural control, which can promote walking stability through a feedback/reactive mechanism. Since gaze behavior alone gives no indication as to what information is gathered and the functions it serves, we aimed to investigate the cognitive demands associated with downward gazing, as they are likely to differ between anticipatory and feedback use of visual input. To do so, we used a novel methodology to compromise walking stability in a manner that could not be resolved through modulation of stepping. Then, using interference methodology and neuroimaging, we tested for (1) interference related to dual tasking, and (2) changes in prefrontal activity. The novel methodology resulted in an increase in the time spent looking at the walking surface. Further, while some dual-task interference was observed, indicating that this gaze behavior is cognitively demanding, several gaze parameters pertaining to downward gazing and prefrontal activity correlated. These correlations revealed that a greater tendency to gaze onto the walking surface was associated with lower PFC activity, as is expected when sensory information is used through highly automatic, and useful, neural circuitry. These results, while not conclusive, do suggest that gazing onto the walking surface can be used for purposes other than anticipatory stepping control, bearing important motor-control and clinical implications.
当行走需要引导时，人们常常会向下凝视。这种注视行为被认为通过预期的脚步控制来促进行走稳定性。本研究是正在进行的研究的一部分，旨在探究向下凝视是否也有助于增强姿势控制，通过反馈/反应机制来促进行走稳定性。由于仅仅通过注视行为无法确定收集了哪些信息以及其作用，因此我们旨在探究与向下凝视相关的认知需求，因为它在预期和反馈使用视觉输入之间可能存在差异。为此，我们使用了一种新的方法，以一种无法通过调节步伐来解决的方式来破坏行走稳定性。然后，我们使用干扰方法和神经影像学来测试（1）与双重任务相关的干扰，以及（2）前额叶活动的变化。新方法导致人们注视行走表面的时间增加。此外，尽管观察到一些双重任务干扰，表明这种注视行为具有认知需求，但与向下凝视和前额叶活动相关的几个注视参数存在相关性。这些相关性表明，注视行走表面的倾向越大，前额叶活动越低，这与当通过高度自动且有用的神经回路使用感觉信息时的预期情况相符。虽然这些结果尚不确定，但它们确实表明，注视行走表面可能不仅仅用于预期的脚步控制，这对运动控制和临床具有重要意义。
