Holste Katherine G, Yasen Alia L, Hill Matthew J, Christie Anita D
1 University of Oregon.
Motor Control. 2016 Oct;20(4):380-94. doi: 10.1123/mc.2014-0047. Epub 2016 Aug 19.
The purpose of this study was to assess the effect of a cognitive task on motor cortex excitability and inhibition. Transcranial magnetic stimulation of the motor cortex was performed on 20 healthy individuals (18-24 years; 9 females) to measure motor evoked potentials (MEPs) and cortical silent periods at baseline, during, and following a secondary cognitive task. The MEP amplitude increased from 0.50 ± 0.09-0.87 ± 0.50 mV during a secondary cognitive task (p = .04), and returned to baseline (0.48 ± 0.31 mV; p = .90) posttask. The CSP duration also increased from 93.48 ± 28.76-113.6 ± 33.68 ms (p = .001) during the cognitive task, and returned to baseline posttask (89.0 ± 6.9 ms; p = .88). In the presence of a cognitive task, motor cortex excitability and inhibition were both increased relative to baseline. The increase in inhibition may help to explain the motor deficits experienced while performing a secondary cognitive task.
本研究的目的是评估一项认知任务对运动皮层兴奋性和抑制性的影响。对20名健康个体（18 - 24岁；9名女性）进行运动皮层的经颅磁刺激，以测量在基线期、进行一项次级认知任务期间以及任务结束后运动诱发电位（MEP）和皮层静息期。在次级认知任务期间，MEP波幅从0.50±0.09 mV增加至0.87±0.50 mV（p = 0.04），任务结束后恢复至基线水平（0.48±0.31 mV；p = 0.90）。在认知任务期间，CSP持续时间也从93.48±28.76 ms增加至113.6±33.68 ms（p = 0.001），任务结束后恢复至基线水平（89.0±6.9 ms；p = 0.88）。在存在认知任务的情况下，相对于基线，运动皮层的兴奋性和抑制性均增加。抑制性的增加可能有助于解释在执行次级认知任务时所经历的运动缺陷。
