Wow, check out this man who’ve had a hand transplant after 35 years of non-use on his amputated arm. I am still amazed at the fact the hand transplant itself was successful, I dearly hope for every amputated person to get their arms/legs back through transplants.
When Savage had both hands, part of his right brain responded to his left hand, and a corresponding part of his left brain responded to his right hand. After the amputation, that same part of his left brain would have been sensory-deprived and thus ready to adopt duties of adjacent sensory areas, such as those for the right arm and possibly his face.
Much animal and human research has documented that such neural reorganization begins within hours of limb loss or debilitation…
“It’s remarkable that an original neural pathway for the hand can be reinstated after years and years,” (Vanderbilt University neuroscientist Jon) Kaas says.