The Brain on Love

"When two people become a couple, the brain extends its idea of self to include the other; instead of the slender pronoun “I,” a plural self emerges who can borrow some of the other’s assets and strengths. The brain knows who we are. The immune system knows who we’re not, and it stores pieces of invaders as memory aids. Through lovemaking, or when we pass along a flu or a cold sore, we trade bits of identity with loved ones, and in time we become a sort of chimera. We don’t just get under a mate’s skin, we absorb him or her. Love is the best school, but the tuition is high and the homework can be painful. As imaging studies by the U.C.L.A. neuroscientist Naomi Eisenberger show, the same areas of the brain that register physical pain are active when someone feels socially rejected. That’s why being spurned by a lover hurts all over the body, but in no place you can point to. Or rather, you’d need to point to the dorsal anterior cingulate cortex in the brain, the front of a collar wrapped around the corpus callosum, the bundle of nerve fibers zinging messages between the hemispheres that register both rejection and physical assault. Whether they speak Armenian or Mandarin, people around the world use the same images of physical pain to describe a broken heart, which they perceive as crushing and crippling. It’s not just a metaphor for an emotional punch. Social pain can trigger the same sort of distress as a stomachache or a broken bone.
 But a loving touch is enough to change everything."
 By Diane Ackerman /NYTimes/ more