Joined at the Mind?

A remarkable story in today's NYT Magazine profiles Tatiana and Krista Hogan, four-year-old twins who are joined at the head and share a neural bridge between their thalimi, the brain centers that process sensory information. Reporter Susan Dominus does a great job exploring the medical, philosophical, and social questions raised by the twins' circumstance. There is strong evidence that when one girl sees, hears, tastes, or feels something, the other experiences it, too. Despite their extraordinary neuronal connection, the girls remain (even when it is a struggle) distinct individuals. And despite the fact that the rest of us do not share neurons,  we sure do share insights, sensations, emotions, and experiences with one another. All the time. Sharing a brain may give you a head start toward sharing your mind, but it's not necessary.