Spatio-temporal properties of the pattern of evoked phantom sensations in a left index amputee patient.

In a left index finger amputee, appropriate stimulation of skin areas of the remnant left fingers or left lower face evoked veridical sensations as well as sensations localized to the phantom finger. Five months after the amputation, there was a systematic correspondence between positions of digital and facial stimuli and positions of stimuli felt on the phantom. More than 3 years after the amputation, orderly maps of the phantom index on the ipsilateral fingers were still detected. By contrast, poorly organized facial maps were present only contralaterally to the amputation. The maps on the remnant fingers are likely to acquire stability because they are systematically activated during manipulations performed with the mutilated hand. The disorganization of facial maps may be related to their irrelevance for behavioral control in everyday life conditions.