Walking onto a stationary platform that had been previously experienced as moving generates a locomotor after-effect—the so-called ‘broken escalator’ phenomenon. The motor responses that occur during locomotor after-effects have been mapped theoretically using a hierarchal Bayesian model of brain function that takes into account current sensory information that is weighted according to prior contextually-relevant experiences; these in turn inform automatic motor responses. Here, we use the broken escalator phenomenon to explore motor learning in patients with functional gait disorders and probe whether abnormal postural mechanisms override ascending sensory information and conscious intention, leading to maladaptive and disabling gait abnormalities. Fourteen patients with functional gait disorders and 17 healthy control subjects walked onto a stationary sled (‘Before’ condition, five trials), then onto a moving sled (‘Moving’ condition, 10 trials) and then again onto the stationary sled (‘After’ condition, five trials). Subjects were warned of the change in conditions. Kinematic gait measures (trunk displacement, step timing, gait velocity), EMG responses, and subjective measures of state anxiety/instability were recorded per trial. Patients had slower gait velocities in the Before trials (P < 0.05) but were able to increase this to accommodate the moving sled, with similar learning curves to control subjects (P = 0.87). Although trunk and gait velocity locomotor after-effects were present in both groups, there was a persistence of the locomotor after-effect only in patients (P < 0.05). We observed an increase in gait velocity during After trials towards normal values in the patient group. Instability and state anxiety were greater in patients than controls (P < 0.05) only during explicit phases (Before/After) of the task. Mean ‘final’ gait termination EMG activity (right gastrocnemius) was greater in the patient group than controls. Despite a dysfunctional locomotor system, patients show normal adaptive learning. The process of de-adaptation, however, is prolonged in patients indicating a tendency to perpetuate learned motor programmes. The trend to normalization of gait velocity following a period of implicit motor learning has implications for gait rehabilitation potential in patients with functional gait disorders and related disorders (e.g. fear of falling).

中文翻译：

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功能性步态障碍患者的独立运动学习和适应障碍。

行走到以前在移动中经历过的固定平台上会产生运动后效应，即所谓的“自动扶梯损坏”现象。理论上已经使用大脑功能的分级贝叶斯模型对运动后效应期间发生的运动反应进行了映射，该模型考虑了根据先前上下文相关经验加权的当前感官信息。这些依次通知自动电动机响应。在这里，我们使用断裂的自动扶梯现象来探索功能性步态障碍患者的运动学习，并探究异常的姿势机制是否会覆盖提升的感觉信息和意识，从而导致适应不良和使步态异常。14名具有功能性步态障碍的患者和17名健康对照组受试者走到固定雪橇上（“之前”状态，进行了5次试验），然后走到移动雪橇上（“移动”状态，进行了10次试验），然后又走到了固定雪橇上（“之后”条件，五次审判）。受试者被警告病情变化。每个试验记录运动步态测量值（躯干位移，步速，步态速度），EMG反应和状态焦虑/不稳定性的主观测量值。在之前的试验中，患者的步态速度较慢（每个试验记录EMG反应和状态焦虑/不稳定性的主观测量。在之前的试验中，患者的步态速度较慢（每个试验记录EMG反应和状态焦虑/不稳定性的主观测量。在之前的试验中，患者的步态速度较慢（P  <  0.05），但能够增加该值以适应移动的雪橇，学习曲线与对照对象相似（P  =  0.87）。尽管两组均存在躯干和步态速度运动后遗症，但仅在患者中存在运动后遗症的持续存在（P  <  0.05）。我们观察到在After试验期间步态速度在患者组中朝着正常值增加。患者的不稳定性和状态焦虑大于对照组（P  < 0.05）仅在任务的明确阶段（之前/之后）。患者组的平均“最终”步态终止肌电活动（右腓肠肌）大于对照组。尽管运动系统功能异常，患者仍显示正常的适应性学习。然而，患者的反适应过程延长了，这表明有使学习的运动程序永久化的趋势。一段时间的内隐运动学习后步态速度正常化的趋势对功能性步态障碍和相关障碍（例如跌倒的恐惧）患者的步态康复潜力产生了影响。