Valls-Solé J, Solé A, Valldeoriola F, Muñoz E, Gonzalez L E, Tolosa E S
Departament de Medicina, Hospital Clinic Villarroel, Universitat de Barcelona, Spain.
Neurosci Lett. 1995 Aug 4;195(2):97-100. doi: 10.1016/0304-3940(94)11790-p.
We studied the effects of collision between a voluntary command and the startle response by interrupting a simple visual reaction time task with an acoustic startle. We observed two main effects. First, the reaction time was markedly shortened when the startle was delivered at intervals of 0-75 ms after the 'go' signal. Second, the startle response elicited when the subject's attention was focused onto reacting to the visual 'go' signal involved more muscles and induced larger EMG responses than when the startling stimulus was delivered unexpectedly. Startle response and voluntary commands may share a number of structures along the motor path. Reaction time can be shortened up to the latency of a startle response if the voluntary command is issued a short time after the startling stimulus. Facilitation of the startle responses during motor preparation may be due to the excitability enhancement that occurs in various neural structures along the motor path before the onset of EMG activity.
我们通过在一个简单的视觉反应时间任务中插入听觉惊吓刺激，研究了自主指令与惊吓反应之间碰撞的影响。我们观察到两个主要影响。第一，当在“开始”信号发出后的0 - 75毫秒间隔内施加惊吓刺激时，反应时间显著缩短。第二，当受试者的注意力集中在对视觉“开始”信号做出反应时引发的惊吓反应，比意外施加惊吓刺激时涉及更多肌肉且诱发更大的肌电图反应。惊吓反应和自主指令可能在运动路径上共享许多结构。如果在惊吓刺激后短时间内发出自主指令，反应时间可缩短至惊吓反应的潜伏期。运动准备过程中惊吓反应的促进可能是由于在肌电图活动开始前，运动路径上各种神经结构中发生的兴奋性增强。
