Department of Physiology and Pharmacology, Sapienza University, Piazzale Aldo Moro 5, 00185 Rome, Italy.
J Neurophysiol. 2011 Sep;106(3):1454-66. doi: 10.1152/jn.00995.2010. Epub 2011 Jun 22.
Canceling a pending movement is a hallmark of voluntary behavioral control because it allows us to quickly adapt to unattended changes either in the external environment or in our thoughts. The countermanding paradigm allows the study of inhibitory processes of motor acts by requiring the subject to withhold planned movements in response to an infrequent stop-signal. At present the neural processes underlying the inhibitory control of arm movements are mostly unknown. We recorded the activity of single units in the rostral and caudal portion of the dorsal premotor cortex (PMd) of monkeys trained in a countermanding reaching task. We found that among neurons with a movement-preparatory activity, about one-third exhibit a modulation before the behavioral estimate of the time it takes to cancel a planned movement. Hence these neurons exhibit a pattern of activity suggesting that PMd plays a critical role in the brain networks involved in the control of arm movement initiation and suppression.
取消待执行的运动是自愿行为控制的一个显著特点，因为它使我们能够快速适应外部环境或思维中未被注意到的变化。撤销范式允许通过要求主体在响应不频繁的停止信号时抑制计划的运动，来研究运动行为的抑制过程。目前，手臂运动抑制控制的神经过程大多未知。我们记录了在进行撤销到达任务训练的猴子的背侧运动前皮层（PMd）的头侧和尾侧部分的单个单元的活动。我们发现，在具有运动准备活动的神经元中，大约有三分之一在行为估计取消计划运动所需时间之前表现出调制。因此，这些神经元表现出一种活动模式，表明 PMd 在涉及手臂运动启动和抑制控制的大脑网络中起着关键作用。
