What is left over if I subtract the fact that my arm goes up from the fact that I raise my arm? Neurological evidence invites the provocative hypothesis that what is left over is a phantom arm movement-a movement of an arm that has been amputated. After arm/hand amputation, many amputees report that they can generate voluntary movements of the phantom limb; that is, they can move the arm that was amputated. But what is it like to move an arm/hand that is not there? Here, we review what is currently known about phantom limb movements at three descriptive levels: the kinematic level, the muscle level, and the cortical level. We conclude that phantom arm movements are best conceptualized as the real movements of a dematerialized hand.

中文翻译：

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然而它却在移动：我们目前对幻影手臂运动的了解。

如果我从举起手臂的事实中减去手臂向上的事实，还剩下什么？神经学证据提出了一个挑衅性的假说，即剩下的只是幻影手臂的运动，即被截肢的手臂的运动。手臂截肢后，许多截肢者报告说他们可以产生幻肢的自愿运动。也就是说，他们可以移动被截肢的手臂。但是，移动不存在的手臂/手感觉如何？在这里，我们以三个描述性级别回顾了有关幻肢运动的当前知识：运动级，肌肉级和皮质级。我们得出的结论是，幻像手臂的运动最好被概念化为去实体化的手的真实运动。