The human brain represents the body in a homuncular fashion. Although these cortical representations are to some degree plastic, it is unclear how extensive this plasticity can be. Examinations of amputated or amelic subjects can contribute to answering this question. We examined a man who lacked both arms since birth and was free of phantom pain. Magnetic source imaging revealed that not only had the somatotopically adjacent representation of the lip moved into the cortical space usually representing the hand; but the representation of the foot had similarly moved towards the cortical hand area. These data illustrate a case of extensive cortical reorganization and suggest that the potential overlap of different body parts is much greater than previously anticipated.
