Previous research has suggested that autism is linked to damage to a part of the brain called the brainstem in the early stages of development.

BBC: Differences found in autistic brains

Another common problem for children with spina bifida is called hindbrain herniation in which part of the brain and brainstem slip into the spinal column.

CNN: Study: Major benefits for spina bifida surgery in the womb

An audience of several thousand people, who packed a cavernous hall for a talk billed as "The View from Inside Rainn Wilson's Brainstem, " laughed along.

CNN: Rainn Wilson: "The Internet is the future of spirituality"