Müller Carl, Kopiske Karl
Cognitive Systems Lab, Institute of Physics, Chemnitz University of Technology, Reichenhainer Str. 70, 09126, Chemnitz, Germany.
Sci Rep. 2025 Jan 8;15(1):1375. doi: 10.1038/s41598-024-85091-8.
Walking is one of the most common forms of self-motion in humans. Most humans can walk effortlessly over flat uniform terrain, but also a variety of more challenging surfaces, as they adjust their gait to the demands of the terrain. In this, they rely in part on the perception of their own gait and of when it needs to be adjusted. Here, we investigated how well N = 48 participants detected speed differences between two belts of a split-belt treadmill. As participants walked at a constant speed, we either accelerated or decelerated one of the belts at quasi-random intervals and asked participants to judge their relative speeds in a two-alternative forced-choice task. Using an adaptive psychophysical procedure, we obtained precise perception-threshold estimates for inter-leg speed differences after accelerating or decelerating one belt. We found that most participants could detect even very small speed differences, with mean threshold estimates of just over 7% for both perturbation types. These were relatively stable within, but highly variable across participants. Increased-speed and decreased-speed thresholds were highly correlated, indicating that despite different biomechanics, the detection mechanisms might be similar. This sheds light on how perceiving their own motion helps humans manage interlimb coordination in perturbed walking.
行走是人类最常见的自我移动形式之一。大多数人能够毫不费力地在平坦均匀的地形上行走，而且在调整步态以适应地形需求时，也能在各种更具挑战性的表面上行走。在这一过程中，他们部分依赖于对自身步态以及何时需要调整步态的感知。在此，我们研究了N = 48名参与者检测分体式跑步机两条跑带之间速度差异的能力。当参与者以恒定速度行走时，我们以准随机间隔对其中一条跑带进行加速或减速，并要求参与者在二选一的强制选择任务中判断两条跑带的相对速度。使用自适应心理物理学程序，我们在加速或减速一条跑带后获得了腿部间速度差异的精确感知阈值估计。我们发现，大多数参与者甚至能够检测到非常小的速度差异，两种扰动类型的平均阈值估计略高于7%。这些阈值在个体内部相对稳定，但在不同参与者之间差异很大。加速和减速阈值高度相关，这表明尽管生物力学不同，但检测机制可能相似。这揭示了对自身运动的感知如何帮助人类在受干扰的行走中管理肢体间的协调。
