These poor men and women endured strokes, seizures, saber gashes, botched surgeries, and accidents so horrific that their survivals seemed little short of miracles. To say these people “survived,” though, doesn’t quite capture the truth. Their bodies survived, but their minds didn’t quite; their minds were warped into something new.

Some people lost all fear of death; others started lying incessantly; a few became pedophiles. But however startling, in one way these transformations proved predictable, since people with the same deficit tended to have damage in the same area of the brain—offering vital clues about what those areas did.

There are a thousand and one such stories in neuroscience. These tales expand our notions of what the brain is capable of, and show that when one part of the mind shuts down, something new and unpredictable and sometimes even beautiful roars to life.