Cognitive Neuroscience, Institute of Neuroscience and Medicine (INM-3), Research Centre Jülich, D-52425 Jülich, Germany; Heisenberg Research Group of Computational Neuroscience - Modeling Neural Network Function, Institute of Zoology, University of Cologne, D-50674 Köln, Germany.
Cognitive Neuroscience, Institute of Neuroscience and Medicine (INM-3), Research Centre Jülich, D-52425 Jülich, Germany.
Neuropsychologia. 2018 Aug;117:520-529. doi: 10.1016/j.neuropsychologia.2018.07.006. Epub 2018 Jul 9.
Motor performance declines with normal aging. Previous neuroimaging work revealed aging-related general increases in neural activity, especially in the prefrontal and pre-motor areas, associated with a loss of hemispheric lateralization. However, the functional mechanisms underlying these changes and their relation to aging-associated motor decline to date remain elusive. To further elucidate the neural processes underlying aging-related motor decline, we recorded EEG from younger and older subjects while they performed a finger-tapping task. As a measure of synchronization between motor areas, we computed the inter-regional phase-locking value which reflects functional connectivity between distinct neural populations. Behavioral data revealed increased movement times in older subjects. EEG data showed that phase locking in the δ-θ frequencies is a general, age-independent phenomenon underlying the execution of simple finger movements. In stark contrast, the extent of synchronization between motor areas significantly differed dependent upon age of subjects: multiple additional intra- and inter-hemispheric connections were observed in older subjects. Our data shed light upon the results of previous neuroimaging studies showing aging-related increases in neural activation. In particular, data suggest that the observed aging-dependent substantial intra- and inter-hemispheric reorganization of connectivity between the corresponding motor areas underlies the previously reported loss of lateralization in older subjects. The changes observed are likely to represent compensatory mechanisms aiming at preserved task performance in older subjects.
随着正常衰老，运动表现会下降。先前的神经影像学研究揭示了与衰老相关的神经活动普遍增加，特别是在前额叶和运动前区域，这与半球侧化的丧失有关。然而，这些变化的功能机制及其与与衰老相关的运动下降的关系至今仍不清楚。为了进一步阐明与衰老相关的运动下降的神经过程，我们在年轻和年长的参与者执行手指敲击任务时记录了他们的 EEG。作为运动区域之间同步性的度量，我们计算了区域间的相位锁定值，该值反映了不同神经群体之间的功能连接。行为数据显示，年长的参与者的运动时间增加。EEG 数据表明，在 δ-θ 频率下的锁定是执行简单手指运动的普遍的、与年龄无关的现象。相比之下，运动区域之间的同步程度取决于参与者的年龄：在年长的参与者中观察到多个额外的内和半球间连接。我们的数据揭示了先前神经影像学研究结果，这些研究表明与衰老相关的神经激活增加。特别是，数据表明，观察到的与衰老相关的、在相应的运动区域之间的连接的显著的内和半球间重组，是先前报道的年长的参与者中侧化丧失的基础。观察到的变化可能代表了旨在保持年长的参与者的任务表现的补偿机制。
