Rapid sensory remapping in the adult human brain as inferred from phantom breast perception

We provide evidence for a perceptual marker of neuroplasticity in female mastectomy patients who reported phantom breast perceptions. When tactile stimuli were delivered to dorso-thoracic, shoulder and pinna regions ipsilateral to the mastectomy, these patients (in some cases even 5 days after the operation) referred the stimuli to the amputated breast mainly to the nipple. The somatosensory representation of the stimulated regions is probably adjacent to the former representation of the amputated breast. These results suggest that input from stimulated regions of the skin can drive neurones originally driven by input from the amputated breast. The apparent functional relation between pinna and nipple might give clues to the mechanisms underlying referred sensations and pain.