Korivand Soroush, Jalili Nader, Gong Jiaqi
Department of Mechanical Engineering, The University of Alabama, Tuscaloosa, AL, United States.
Department of Computer Science, The University of Alabama, Tuscaloosa, AL, United States.
Front Neurosci. 2023 Mar 1;17:1051500. doi: 10.3389/fnins.2023.1051500. eCollection 2023.
Human locomotion is affected by several factors, such as growth and aging, health conditions, and physical activity levels for maintaining overall health and well-being. Notably, impaired locomotion is a prevalent cause of disability, significantly impacting the quality of life of individuals. The uniqueness and high prevalence of human locomotion have led to a surge of research to develop experimental protocols for studying the brain substrates, muscle responses, and motion signatures associated with locomotion. However, from a technical perspective, reproducing locomotion experiments has been challenging due to the lack of standardized protocols and benchmarking tools, which impairs the evaluation of research quality and the validation of previous findings.
This paper addresses the challenges by conducting a systematic review of existing neuroimaging studies on human locomotion, focusing on the settings of experimental protocols, such as locomotion intensity, duration, distance, adopted brain imaging technologies, and corresponding brain activation patterns. Also, this study provides practical recommendations for future experiment protocols.
The findings indicate that EEG is the preferred neuroimaging sensor for detecting brain activity patterns, compared to fMRI, fNIRS, and PET. Walking is the most studied human locomotion task, likely due to its fundamental nature and status as a reference task. In contrast, running has received little attention in research. Additionally, cycling on an ergometer at a speed of 60 rpm using fNIRS has provided some research basis. Dual-task walking tasks are typically used to observe changes in cognitive function. Moreover, research on locomotion has primarily focused on healthy individuals, as this is the scenario most closely resembling free-living activity in real-world environments.
Finally, the paper outlines the standards and recommendations for setting up future experiment protocols based on the review findings. It discusses the impact of neurological and musculoskeletal factors, as well as the cognitive and locomotive demands, on the experiment design. It also considers the limitations imposed by the sensing techniques used, including the acceptable level of motion artifacts in brain-body imaging experiments and the effects of spatial and temporal resolutions on brain sensor performance. Additionally, various experiment protocol constraints that need to be addressed and analyzed are explained.
人类的运动受多种因素影响，如生长发育与衰老、健康状况以及维持整体健康和幸福感的身体活动水平。值得注意的是，运动功能受损是导致残疾的常见原因，对个体的生活质量有重大影响。人类运动的独特性和高发性引发了大量研究，旨在开发用于研究与运动相关的脑基质、肌肉反应和运动特征的实验方案。然而，从技术角度来看，由于缺乏标准化方案和基准测试工具，重现运动实验一直具有挑战性，这影响了研究质量的评估和先前研究结果的验证。
本文通过对现有的关于人类运动的神经影像学研究进行系统综述来应对这些挑战，重点关注实验方案的设置，如运动强度、持续时间、距离、采用的脑成像技术以及相应的脑激活模式。此外，本研究还为未来的实验方案提供了实用建议。
研究结果表明，与功能磁共振成像（fMRI）、功能近红外光谱技术（fNIRS）和正电子发射断层扫描（PET）相比，脑电图（EEG）是检测脑活动模式的首选神经影像学传感器。行走是研究最多的人类运动任务，这可能是由于其基本性质以及作为参考任务的地位。相比之下，跑步在研究中受到的关注较少。此外，使用fNIRS以60转/分钟的速度在测力计上骑行提供了一些研究依据。双任务行走任务通常用于观察认知功能的变化。此外，运动研究主要集中在健康个体上，因为这是最接近现实世界自由生活活动的场景。
最后，本文根据综述结果概述了建立未来实验方案的标准和建议。它讨论了神经和肌肉骨骼因素以及认知和运动需求对实验设计的影响。它还考虑了所用传感技术带来的局限性，包括脑-体成像实验中可接受的运动伪影水平以及空间和时间分辨率对脑传感器性能的影响。此外，还解释了各种需要解决和分析的实验方案限制因素。
