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The Science of Sex: The Anatomy of Love

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The Anatomy of Love index

“Tell me where is fancy bred: In the heart or in the head?” asked Shakespeare, that scientist of the emotions. In the head, according to a study by two researchers at University College London — who took a slightly less literary tack to the question. Specifically, they have tracked down the seat of romantic love to the insula, the “anterior cingulate gyrus” and a few other little-known corners of the brain.

The study, which appears in this week’s NeuroReport, was done by neuroscientist Semir Zeki and his Swiss graduate student Andreas Bartels. A couple of years ago the two distributed posters around London, advertising for volunteers who were “truly, deeply and madly in love.” Seventy women and men responded, and seventeen of these (eleven women and six men — all heterosexual) were selected for the study. The subjects had had a relationship with their respective beloveds for an average of over two years; some were married and others unwed.

    

After filling out a “passionate love questionnaire,” these seventeen were ready to have their most intimate emotions bared to the world, with the help of a functional magnetic resonance imaging (fMRI) scanner. This high-tech mind-reader constructs images of the brain in which changes in blood flow (induced by brain activity) are represented as color-coded pixels.

    

“It is engender’d in the eyes/With gazing fed.” To make the subjects experience the emotion of romantic love while lying in the unromantic bowels of the fMRI scanner, Bartels and Zeki gave each subject a photo of his or her lover to gaze upon. Of course, a whole lot goes on in the brain when you look at a picture, most of which has
nothing to do with the emotion of love. To get rid of the irrelevant stuff, the researchers alternated the picture of each subject’s partner with pictures of several other friends with whom the subject was not in love. They then digitally subtracted the “friends” images from the “beloved” image, leaving an image that just represented the differences between the two. These, the researchers argue, are the regions that become more or less active when a person experiences the emotion of romantic love.

    
One of the regions that becomes more active is a deeply infolded zone of the cerebral cortex named the insula (see the illustration).
The insular cortex has been known to play a role in emotions — both negative and positive ones — for some time. Interestingly, the insula in the left hemisphere was far more active than the corresponding region in the right hemisphere. So much for the popular notion that the left and right hemispheres are the homes of reason and emotion, respectively.

    

Among the regions whose activity decreased during the experience of love were zones previously implicated in the experience of painful emotions such as sadness, anger and fear. These include the prefrontal cortex of the right hemisphere and a deep (subcortical) structure known as the amygdala. It appears that the brain regions serving positive and negative emotions have a reciprocal, see-saw relationship, such that love diminishes anger and vice versa.

    

Most of the regions that were activated during the experience of romantic love have previously been shown to be active while a subject is under the influence of euphoria-inducing drugs such as opiates and cocaine. Apparently, both romantic love and those drugs activate a “blissed-out” circuit in the brain.

    

Still, this finding raises the usual question one must ask when attempting to measure a tough-to-define emotional experience: Are Bartels and Zeki studying what they think they’re studying? All their subjects were in satisfying ongoing relationships, suggesting that they were happily in love. But romantic love is often unrequited, and that is far from a happy experience; it can lead to depression, even suicide. I’d guess that if Bartels and Zeki had tested a bunch of unhappy — but definitely “in love” — lovers they would have gotten a very different pattern of activity from the one they report. In other words, I question whether all the brain centers that lit up in their experiments are truly involved in the experience of love itself, rather than the euphoria of having one’s love reciprocated, a euphoria that might apply to other emotional circumstances having nothing to do with romance.

    

“And fancy dies/In the cradle where it lies.” Romantic love is usually short-lived, giving way to a more durable “companionate” love — or to indifference. Because the fMRI technique lets researchers look inside the brains of living people, studying individuals over the entire course of a “love attack” might give us much more insight into exactly which brain regions are involved, and what they contribute.

    

Brain research has traditionally focused on cognitive processes such as how we see; only recently has it come to grips with touchy-feely topics like our emotions. I applaud this new direction, but I worry too. Is romantic love a robust enough phenomenon to stand up to this kind of scrutiny? Will we continue to love — or to celebrate love in poetry — when we know it to be nothing but a cingulo-insular reflex? Perhaps. But (call me a cynic) I doubt it.

    

“Let us all ring fancy’s knell; I’ll begin it: Ding, dong, bell.”