Friday, May 27, 2011

shared consciousness?

The world is a strange and wonderful place. Here's an article about conjoined twins: two girls joined at the head. What makes them special isn't so much the nature of the conjoining as the presence of a thin, connective line that has been dubbed a "thalamic bridge":

Twins joined at the head — the medical term is craniopagus — are one in 2.5 million, of which only a fraction survive. The way the girls’ brains formed beneath the surface of their fused skulls, however, makes them beyond rare: their neural anatomy is unique, at least in the annals of recorded scientific literature. Their brain images reveal what looks like an attenuated line stretching between the two organs, a piece of anatomy their neurosurgeon, Douglas Cochrane of British Columbia Children’s Hospital, has called a thalamic bridge, because he believes it links the thalamus of one girl to the thalamus of her sister. The thalamus is a kind of switchboard, a two-lobed organ that filters most sensory input and has long been thought to be essential in the neural loops that create consciousness. Because the thalamus functions as a relay station, the girls’ doctors believe it is entirely possible that the sensory input that one girl receives could somehow cross that bridge into the brain of the other. One girl drinks, another girl feels it.

While not exactly hinting at telepathy in the sci-fi sense, this phenomenon is still pretty damn amazing, to put it mildly.


1 comment:

Elisson said...

Situations such as these lead us to question the very notion of "selfness." Read Elizabeth Moon's The Speed of Dark for some other thoughts on the matter. Written (partly) from the POV of an autist, the novel poses the question: if there were a drug that cured autism, would it eliminate the feeling of "self" in those who underwent therapy?

And another question suggests itself: If twins are joined at the nostrils, would that condition be called "snuffleupagus"?