It is difficult to identify the precise neural deficits associated with congenital amusias because no two brains start out the same; they grow and remap in ways that are influenced by genetics, environment, culture, and random factors. The acquired amusias aren’t all that much easier because damage to the brain is never exactly the same from one patient to the next—nature’s experiments are not carefully controlled the way laboratory experiments are. But we have been able to draw out some patterns.
