Institute of Clinical Neuroscience and Medical Psychology, Medical Faculty, Heinrich-Heine-University, Duesseldorf, Germany.
Institute of Clinical Neuroscience and Medical Psychology, Medical Faculty, Heinrich-Heine-University, Duesseldorf, Germany.
Neuroimage Clin. 2018 Aug 10;20:448-457. doi: 10.1016/j.nicl.2018.08.009. eCollection 2018.
Motor sequence learning plays a pivotal role in various everyday activities. Motor-cortical beta oscillations have been suggested to be involved in this type of learning. In Parkinson's disease (PD), oscillatory activity within cortico-basal-ganglia circuits is altered. Pathologically increased beta oscillations have received particular attention as they may be associated with motor symptoms such as akinesia. In the present magnetoencephalography (MEG) study, we investigated PD patients and healthy controls (HC) during implicit motor sequence learning with the aim to shed light on the relation between changes of cortical brain oscillations and motor learning in PD with a particular focus on beta power. To this end, 20 PD patients (ON medication) and 20 age- and sex-matched HC were trained on a serial reaction time task while neuromagnetic activity was recorded using a 306-channel whole-head MEG system. PD patients showed reduced motor sequence acquisition and were more susceptible to interference by random trials after training on the task as compared to HC. Behavioral differences were paralleled by changes at the neurophysiological level. Diminished sequence acquisition was paralleled by less training-related beta power suppression in motor-cortical areas in PD patients as compared to HC. In addition, PD patients exhibited reduced training-related theta activity in motor-cortical areas paralleling susceptibility to interference. The results support the hypothesis that the acquisition of a new motor sequence relies on suppression of motor-cortical beta oscillations, while motor-cortical theta activity might be related to stabilization of the learned sequence as indicated by reduced susceptibility to interference. Both processes appear to be impaired in PD.
运动序列学习在各种日常活动中起着关键作用。皮质-β振荡被认为参与了这种类型的学习。在帕金森病（PD）中，皮质基底神经节回路中的振荡活动发生改变。病理性增加的β振荡受到了特别关注，因为它们可能与运动症状如运动不能有关。在本脑磁图（MEG）研究中，我们在隐式运动序列学习期间研究了 PD 患者和健康对照者（HC），旨在阐明 PD 患者皮质脑振荡变化与运动学习之间的关系，特别关注β功率。为此，我们对 20 名 PD 患者（服药期间）和 20 名年龄和性别匹配的 HC 进行了一项序列反应时间任务训练，同时使用 306 通道全头 MEG 系统记录神经磁活动。与 HC 相比，PD 患者的运动序列获取减少，并且在任务训练后对随机试验的干扰更敏感。行为差异与神经生理水平的变化平行。与 HC 相比，PD 患者的运动皮质区域的训练相关β功率抑制减少，与序列获取减少平行。此外，PD 患者在运动皮质区域表现出减少的训练相关θ活动，与干扰的易感性平行。结果支持这样的假设，即新的运动序列的获取依赖于运动皮质β振荡的抑制，而运动皮质θ活动可能与所学习序列的稳定有关，如干扰易感性降低所表明的那样。这两个过程在 PD 中似乎都受到了损害。
