I once had a patient who suffered a right hemisphere stroke and fell to the ground, unable to walk because of a paralyzed left leg. She lay on the floor for two days, not because no one came to her aid, but because she kept blithely reassuring her husband that she was fine, that there was nothing wrong with her leg. Only on the third day did he bring her in for treatment. When I asked her why she could not move her left leg, and held it up for her to see, she said indifferently that it was someone else’s leg. Flaherty (2004)

Where is this ability to use language located? The obvious answer is “in the brain.” However, it can’t be just anywhere in the brain. For example, it can’t be where damage was done to the right hemisphere of the patient’s brain in Alice Flaherty’s description. The woman could no longer recognize her own leg, but she could still talk about it. The ability to talk was unimpaired and hence clearly located somewhere else in her brain.