Nov 05, 2010 7:02 PM GMT
I find this absolutely fascinating. It really shows how much we don't know about our own bodies and minds.
For the full story, visit this link: http://www2.macleans.ca/2010/11/02/a-piece-of-their-mind/print/
The odds of their conception were astronomical; of surviving in the womb, let alone a live birth, slim to none. The odds of living past their first day, worse than a coin toss, though not if the small army deployed by Vancouver’s Children’s Hospital had a say in it. And they did. And today, approaching their fourth birthdays on Oct. 25, Tatiana and Krista Hogan are wearing pretty velvet dresses, red and purple respectively. They greet you at the door of their sprawling, unruly home in Vernon, B.C., carrying a bouncy ball, and issuing a command: come play.
You have just enough time to add your shoes to the pile at the entrance and to give their mother, Felicia Simms, a quick greeting before you’re led through the living room and kitchen, to a long, sloping hallway that leads to some of the bedrooms in what was, until this year, a residential home for the elderly. They plant themselves at the bottom. You’re at the top, with their 2½-year-old sister, Shaylee, rolling and fielding their returns. Then the twins want the higher ground, but you’re doing it wrong. “No,” says Tatiana as though dealing with a mental defective. “Bounce it!”
They are the rarest of the rarest of the rare. Tatiana and Krista are not just conjoined, but they are craniopagus, sharing a skull and also a bridge between each girl’s thalamus, a part of the brain that processes and relays sensory information to other parts of the brain. Or perhaps in this case, to both brains. There is evidence that they can see through each other’s eyes and perhaps share each other’s unspoken thoughts. And if that proves true, it will be the rarest thing of all. They will be unique in the world.
They have been drawing international attention, both public and scientific, since before their birth. Dr. Douglas Cochrane, a neurosurgeon at Children’s Hospital, is part of the team that has been watching over them since they were in the womb. Last year he conducted tests in which one twin looked at an object while he measured the brain activity in the other. “Their brains are recording signals from the other twin’s visual field,” he cautiously concluded. “One might be seeing what the other one is seeing.”