Preparation and control of rapid voluntary movements

想象两种截然不同但真实的生活场景。在第一个视频中，一名警察开着巡逻车把一辆疑似被盗的汽车停在路边。警察拔出枪，走到被偷车辆的驾驶座边。当他接近司机时，一辆在警察后面的车“事与愿违”。警察向偷来的车辆开枪，打伤了嫌疑犯。警官是否故意向嫌疑人开枪？在第二种情况下，奥运会田径100米决赛正在进行，世界纪录保持者在之前一次抢跑后“被发令员命令”。发令枪响了，运动员“爆炸”出了起跑线，大多数人认为这是一个好的开始。然而，在发令枪鸣响96毫秒后，他在“起跑器”上记录了力量的增加。国际田联（International Association of Athletics Federation）规定，任何运动员在发令信号发出100毫秒之前，在“起跑块”上加力，一定是“操之过急”。因此，这名运动员被取消资格。运动员是否在没有等待发令枪鸣响的情况下就故意提前出发？这两个场景是否相关？警察和运动员的行为是否都可以解释？很明显，人们每天都需要对日常刺激做出快速反应，而这些动作长期以来一直被认为是通过高级大脑中心（皮层回路）的信息流来控制的。然而，我们最近（和其他人一起）表明，当准备好的反应准备好时，响亮的信号会使个体感到震惊，导致整个反应被释放，在某些情况下，受试者没有意识到反应已经发生。我们观察到，对意外刺激的反应时间低至65毫秒。我们的假设是，准备好的反应是预先编程的，并储存在较低的（皮层下）大脑结构中。当信号到达时，令人震惊的声音会提前触发反应，绕过大脑皮层的处理过程，导致反应时间短。我提出的研究方案将调查导致这种快速准备行动的过程，并阐明它们的准备、储存和执行。

Picture two very different but real life scenarios. In the first a policeman in a patrol car pulls over a suspected stolen vehicle. The officer draws his gun and walks over to the driver side of the stolen vehicle. As he approaches the driver a car that is driving behind the policeman "backfires". The officer discharges his weapon into the stolen vehicle injuring the suspect. Did the officer intentionally fire his gun at the suspect? In the second scenario an Olympic track and field 100m final is underway and the world record holder is "under starter's orders" after having false started once before. The starter pistol is fired and the athlete "explodes" out of the blocks for what most believe to be a good start. However, he has produced an increase in force that is recorded on the "starting blocks" 96 ms after the starter pistol fired. The International Association of Athletics Federation state that any athlete increasing force on the "blocks" before 100 ms has passed after the starter signal must have "jumped the gun". Therefore the athlete was disqualified. Did the athlete intentionally anticipate the start without waiting for the sound of the starter pistol? Are these two scenarios related and can the actions of both the policeman and the athlete be explained? It is clear that fast responses to everyday stimuli are required of people on a daily basis and these movements have long been thought to be controlled via information flow through higher brain centres (cortical loops). However, we have recently shown (along with others) that when the prepared response is ready to go the loud signal has the effect of startling the individual causing the entire response to be released, in some instances without the subject being aware that the response has occurred. We have observed reaction times to unanticipated startling stimuli as low as 65 ms. Our hypothesis is that a prepared response is pre-programmed and stored in lower (subcortical) brain structures. When the signal arrives the response is triggered early by the startling sound, bypassing cortical processing and resulting in short reaction times. The programme of research that I propose will investigate the processes responsible for such fast prepared actions and shed light on their preparation, storage and execution.