Wednesday, September 05, 2007

Study: Romantic love affects brain like drug addiction

A very interesting look at the neurobiology of love. Surprise! There are some striking similarities to addiction:
Her front brain is telling her he's trouble. Look at the facts, it says. He's never made a commitment, he can't keep a job.

But her middle brain won't listen. Man, it swoons, he looks great in those jeans, his black hair curls onto his forehead so adorably. His front brain is lecturing, too: She's flirting with every guy, and she can drink you under the table, it says. His mid-brain is unresponsive, distracted by her come-hither stare.

"What could you be thinking?" their front brains demand.

Their middle brains, each on a quest for reward, pay no heed.

Alas, when it comes to choosing mates, smart neurons can make dumb choices.

...

That initial spark can flash and fade. Or it can become a flame and then a fire, a rush of exhilaration and sense of union that scientists know as passionate love.

Key to this state of seeing a person as a soul mate instead of a one-night stand is the limbic system, nestled deep within the brain between the neocortex (the region responsible for reason and intellect) and the reptilian brain (responsible for primitive instincts). Altered levels of dopamine, norepinephrine and serotonin – neurotransmitters also associated with arousal – wield influence.

But passionate love is also "a drive to win life's greatest prize, the right mating partner," Dr. Fisher says. It is, she says, an addiction.

People in the early throes of passionate love, she says, can think of little else. They describe sleeplessness, loss of appetite and feelings of euphoria, and they're willing to take exceptional risks. Brain areas governing reward, obsession, recklessness and habit all play their part in the trickery.

In an experiment published in the 2006 book Evolutionary Cognitive Neuroscience, Dr. Fisher found 17 people who were in relationships for an average of seven months. All said they'd feel deep despair if their lover left, and they yearned to know all there was to know about the loved one.

She put them in an FMRI to see what areas of their brains got active when they saw a photograph of their beloved ones.

"We saw activity in the ventral tegmental area and other regions of the brain's reward system associated with motivation, elation and focused attention," she said. It's the same part of the brain that presumably is active when gamblers think they're going to win.

...

Lucy Brown, professor of neuroscience at the Albert Einstein College of Medicine, has also taken FMRI images of people in the early days of a new love. In a study reported in the July 2005 Journal of Neurophysiology, she too found key activity in the ventral tegmental area. "That's the area that's also active when a cocaine addict gets an IV injection of cocaine," Dr. Brown says. "It's not a craving. It's a high."

Biologically, the cravings and pleasures unleashed are as strong as any drug. Certain brain regions, scientists have found, are being deactivated, such as within the amygdala, associated with fear. Excited brain messages reach the caudate nucleus, a dopamine-rich area where unconscious habits and skills, such as the ability to ride a bike, are stored.

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