Ramachandran and Blakeslee describe a case of phantom limb;
Tom lost his left arm just above the elbow......In the weeks afterward, even thow he knew that his arm was gone, Tom could still feel its ghostly presence below the elbow. He could wiggle each "finger," "reach out" and "grab" objects that were within arm’s reach. Indeed, his phantom arm seemed to be able to do anything that the real arm would have done automatically, such as warding off blows, breaking falls or patting his little brother on the back. Since Tom had been left-handed, his phantom would reach for the receiver whenever the telephone rang.
[Ramachandran, V. S. & Blakeslee, S. (1998) The Phantoms in the Brain. William Morrow.]
Apparently, the patient’s body still reacted to certain stimuli in a habitual manner. Whenever the telephone rang, his whole body was led to answer it as he used to, and this action involved the movement of the left hand. The sensation of missing limb seems to occur as a part of a habitual action that has been established between the body and a certain situation. The patient need not to represent in his mind the missing part of the body but may feel it immediately, as a need for an embodied action.