SIMPLE REACTION-TIME TO FOCAL TRANSCRANIAL MAGNETIC STIMULATION - COMPARISON WITH REACTION-TIME TO ACOUSTIC, VISUAL AND SOMATOSENSORY STIMULI
SIMPLE REACTION-TIME TO FOCAL TRANSCRANIAL MAGNETIC STIMULATION - COMPARISON WITH REACTION-TIME TO ACOUSTIC, VISUAL AND SOMATOSENSORY STIMULI
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DOI：
10.1093/brain/115.1.109
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发表时间：
1992-02-01
期刊：
影响因子：
14.5
通讯作者：
HALLETT, M
中科院分区：
文献类型：
--
作者：
PASCUALLEONE, A;BRASILNETO, JP;HALLETT, M
我们研究了9名正常人受试者接受快速弯曲一只手臂的训练后，不同go信号对反应时间的影响。听觉刺激的反应时间比视觉或体感刺激的反应时间短，并且与刺激强度呈负相关。 反应时间最长的经颅（磁或电）刺激传递到对侧运动皮层，是足够强大的，以诱导运动诱发电位在响应二头肌。 相反，反应时间是最短的阈下经颅刺激在同一头皮位置或经颅刺激在同侧运动皮层无论强度。阈上经颅刺激的运动皮层似乎短暂抑制神经元负责启动运动程序涉及肌肉中的运动诱发电位已被诱导，从而延长反应时间。 另一方面，阈下刺激解除抑制或直接激活这些神经元，导致反应时间缩短。 运动皮层之间的经胼胝体连接可能是同侧经颅刺激反应时间短的原因。
We studied the effect of different go-signals on the reaction time in nine normal human subjects trained to respond by rapidly flexing one arm. Reaction times to auditory stimuli were shorter than those to visual or somatosensory stimuli, and were inversely correlated with the stimulus intensity. The reaction time was longest to a transcranial (magnetic or electric) stimulus delivered over the contralateral motor cortex that was sufficiently strong to induce a motor evoked potential in the responding biceps. Conversely, reaction time was shortest to either subthreshold transcranial stimulation over the same scalp position or to transcranial stimulation over the ipsilateral motor cortex regardless of intensity.Suprathreshold transcranial stimulation to the motor cortex seems to transiently inhibit the neurons responsible for initiation of motor programs involving muscles in which motor evoked potentials have been induced, thereby prolonging the reaction time. On the other hand, a subthreshold stimulus either disinhibits or directly activates such neurons leading to a shorter reaction time. Transcallosal connections between the motor cortices may account for the short reaction time to ipsilateral transcranial stimulation.