The New York Times has an amazing article on conjoined twins Tatiana and Krista Hogan who share part of their brains and seem to be aware of each others’ minds at work.
It’s a long read but worth it both for how the piece captures both the scientific interest in the possibility of shared consciousness and the personalities of the twins.
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.
We covered an earlier article that touched on whether the two young children had access to each others’ experiences but the NYT piece explores the issue in far more depth.