Jackson Samuel R, Pohlig Ryan T, Morton Susanne M
Department of Physical Therapy, University of Delaware, Newark, Delaware, United States.
Interdisciplinary Graduate Program in Biomechanics & Movement Science, University of Delaware, Newark, Delaware, United States.
J Neurophysiol. 2025 Jun 1;133(6):1807-1814. doi: 10.1152/jn.00502.2024. Epub 2025 May 14.
Our group and others have shown that the presence of an acute painful stimulus may interfere with retention of motor learning. Conversely, other evidence suggests this effect may not be truly due to pain, but due to a change in context when testing retention, i.e., testing retention in a nonpainful context when learning occurred in a painful context. Yet to our knowledge, no study has directly compared the retention of learning acquired under painful conditions with versus without a context change. To answer this question, we tested 30 young, healthy adults on a locomotor learning and retention paradigm. All participants walked on a treadmill with a monitor displaying distorted real-time visual feedback of step lengths to induce learning of an asymmetric stepping pattern. Retention was assessed 24 h later. Participants were randomized into one of three groups: one received no intervention; one received a painful stimulus during learning on only; and one received the same painful stimulus during both learning on and retention testing on . Pain was induced by applying a combination of topical capsaicin cream and superficial heat to the skin of one leg. We found that while all groups successfully learned the asymmetric pattern, retention was reduced in both groups that experienced pain during learning, regardless of the pain context during retention testing. These findings indicate that pain experienced during the acquisition of a motor skill has a unique and deleterious effect on retention of that motor skill, which could negatively impact rehabilitation efforts. Here, we show that acute pain experienced during locomotor learning reduces its 24-h retention regardless of the context in which retention is tested. These findings indicate that pain has a deleterious effect on the retention of newly acquired motor skills, possibly impacting the efficacy of motor learning-based rehabilitation interventions for people with painful conditions.
我们团队以及其他一些团队已经表明，急性疼痛刺激的存在可能会干扰运动学习的记忆保持。相反，其他证据表明，这种效应可能并非真正由疼痛所致，而是由于在测试记忆保持时情境发生了变化，即在疼痛情境中进行学习，而在非疼痛情境中测试记忆保持。然而据我们所知，尚无研究直接比较在有或没有情境变化的情况下，在疼痛条件下获得的学习记忆保持情况。为了回答这个问题，我们在一个运动学习和记忆保持范式中对30名年轻健康的成年人进行了测试。所有参与者在跑步机上行走，跑步机上的监视器显示步长的扭曲实时视觉反馈，以诱导不对称步幅模式的学习。24小时后评估记忆保持情况。参与者被随机分为三组之一：一组不接受干预；一组仅在学习期间接受疼痛刺激；一组在学习和记忆保持测试期间均接受相同的疼痛刺激。通过将局部辣椒素乳膏和体表加热相结合应用于一条腿的皮肤来诱导疼痛。我们发现，虽然所有组都成功学会了不对称模式，但在学习期间经历疼痛的两组中，记忆保持均有所下降，无论在记忆保持测试期间的疼痛情境如何。这些发现表明，在运动技能习得过程中经历的疼痛对该运动技能的记忆保持具有独特的有害影响，这可能会对康复努力产生负面影响。在此，我们表明，运动学习期间经历的急性疼痛会降低其24小时的记忆保持，无论记忆保持测试的情境如何。这些发现表明，疼痛会对新获得的运动技能的记忆保持产生有害影响，可能会影响针对疼痛患者的基于运动学习的康复干预措施的效果。
