Inhibitory control of acquired motor programmes in the human brain
Inhibitory control of acquired motor programmes in the human brain
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DOI：
10.1093/brain/awf030
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发表时间：
2002-02-01
期刊：
影响因子：
14.5
通讯作者：
Gerloff, C
中科院分区：
文献类型：
--
作者：
Hummel, F;Andres, F;Gerloff, C
熟练的人类行为的一个重要基础是适当检索获得和记忆的运动程序（“运动记忆痕迹”）。如果运动程序只在必要时被激活，而在特定情境的背景下被抑制，那么适当的提取是有保证的。目前还不清楚这种类型的抑制是如何在大脑中完成的。我们研究了18名志愿者和6名局灶性肌张力障碍患者的运动记忆痕迹的上下文依赖性调制。皮质功能进行了评估，经颅磁刺激的初级运动皮层（M1）和任务相关的分析振荡脑电图活动。比较了激活（ACT）和抑制（INH）条件。在这两种情况下，视觉线索都以1/s呈现。在ACT中，受试者必须对这些提示做出反应，如在之前的训练课程中学习的那样，用个人手指运动。在INH中，受试者必须观察线索而不检索运动反应。在INH期间，与基线相比，运动诱发电位（MEP）的幅度显著降低证实了运动记忆轨迹的抑制控制。这是伴随着一个显着增加的11-13赫兹振荡活动的感觉运动区在INH。在主动提取运动记忆痕迹的过程中，情况正好相反（MEP振幅增加，11-13 Hz振荡活动减少）。在一个小样本的肌张力障碍患者（n=6），增加11-13赫兹振荡活动在INH是一贯缺席。目前的数据表明，第一次皮质相关的适当的，上下文相关的抑制运动记忆的痕迹。我们建议，振荡活动的局灶性增加是在皮层水平的抑制控制。这一概念得到了支持的初步观察张力障碍患者谁是已知的有缺陷的抑制性运动控制和这些上下文依赖性局灶性增加的振荡活动是缺席。
An important basis of skilled human behaviour is the appropriate retrieval of acquired and memorized motor programmes ('motor memory traces'). Appropriate retrieval is warranted if motor programmes are only activated if necessary and are, probably more often, inhibited if required by the context of a given situation. It is unknown how this type of inhibition is accomplished in the brain. We studied context-dependent modulation of motor memory traces in 18 volunteers and six patients with focal dystonia. Cortical function was assessed with transcranial magnetic stimulation over the primary motor cortex (M1) and with task-related analysis of oscillatory EEG activity. An activation (ACT) and inhibition (INH) condition were compared. In both, visual cues were presented at 1/s. In ACT, subjects had to respond to these cues with individual finger movements as learned in a preceding training session. In INH, subjects had to observe the cues without retrieval of motor responses. During INH, inhibitory control of the motor memory trace was confirmed by significant amplitude reduction of motor evoked potentials (MEPs) compared with baseline. This was accompanied by a significant increase of 11-13 Hz oscillatory activity over the sensorimotor areas during INH. During active retrieval of the motor memory traces, the reverse was true (increased MEP amplitudes, decreased oscillatory 11-13 Hz activity). In a small sample of dystonic patients (n=6), the increase of 11-13 Hz oscillatory activity during INH was consistently absent. The present data demonstrate for the first time cortical correlates of appropriate, context-dependent inhibition of motor memory traces. We propose that focal increases of oscillatory activity are instrumental for inhibitory control at the cortical level. This concept is supported by the preliminary observations in dystonic patients who are known to have deficits of inhibitory motor control and in whom these context-dependent focal increases of oscillatory activity were absent.