When the brain signals 'love'
Only about 5% of mammals, including humans, stick to their partners for a long time. This means that there may be something going on inside the brains of this “faithful” minority that is different from the bigger group who prefer multiple short-term partners. So what do the brains of faithful lovers look like?
Scientific literature about falling in love mostly centers around a league of molecules with powers that make you go a little nuts when you think of, sense or lose your beloved. These molecules are mainly oxytocin (often referred to as the love/trust hormone), serotonin (goes by nickname “mood” hormone” in lay circles) and dopamine (a.k.a “reward” hormone).
I was fascinated to learn that oxytocin is the “love” molecule at work only between partners who are already attached. Between a person and a stranger who is a potential mate, even if administered, it would not work. In fact, in a study, males (who identified themselves as “taken”) who were given a solution involving oxytocin preferred a farther distance from attractive strangers than those who were not “taken.” Oxytocin seems to do a lot more work than mere attachment. It also sets up a “tender trap” for your mate not to wander when he is not in your line of sight. In another study, oxytocin increased the pleasure of touch applied by a partner but not by a stranger. Another really interesting study found that more oxytocin in a man makes him see his partner’s face to be more attractive.
With the work of this league of “lovestruck molecules” at the backdrop comes a new study that traces another scientific aspect of falling in love. This time, it involves the brain circuitry - the signals, where they connect when we start to fall in love. This is of course a big, if not impossible problem if we have to do this with humans. First, we cannot experiment with people’s emotions like love and scan their brains to see what happens when we fall in love. We only see that in the movies. And even if we humans were willing to be subjects, this cannot be done in real time – in that supposedly “magical moment.” So scientists who did the study did the next best thing as far as studying long-term partners go – they studied who else in the mammalian scene are mainly and lastingly attached to one partner. And the accolade goes to the prairie vole.
Prairie voles look like you merged a hamster and a rabbit. They have been the favorite subjects of scientists when they want to study what goes on in the brain when we love. This is because prairie voles form very strong, lasting bonds with their mates, even jointly working throughout their “couplehood” to raise their “pups”. A well-written Smithsonian article about why voles are favorite scientific love subjects even cited the female prairie vole nudging the male prairie vole to do his share of the conjugal responsibility over their pups. When a prairie vole dies, they are survived by the “grieving” partner who exhibits what seems to be depressive behavior.
The study did not produce a complete signal mapping that could account for love but it has started to see that when the “bonding” begins, there is a clear connection between the brain region responsible for “planning and decision-making” (the pre-frontal cortex) and the nucleus accumbens – a brain part that is activated when we feel rewarded. The strength of the signal between the two reliably predicted which ones the prairie voles were attracted to. What was amazing was that in the study, the scientists even tried to artificially stimulate that signal in the brain of a female prairie vole while a male one was just in the vicinity. The female did not even get a chance to mate with the male but when later presented with the male choices, including the ones she saw earlier, she chose the latter. This was quite unsettling as the experiment showed that this “falling in love” could be artificially stimulated.
But of course, for humans, love stories are far more complicated. If it were simple, we would not have to go through several paths through the scientific enterprise – hormones, brain circuitry, behavioral - not to mention the arts and the humanities to untangle the mysteries of our own love relationships.
When science conducts studies on human emotions and relationships and flakes them into bits of hormones and signals, it may seem laughable to some and a complete waste of time to others. But we are creatures who not only love; we also want to understand how we do. That way, we get to understand possible explanations for why we falter when we do, how love is connected with other feelings and the many ways our social ties, woven by love and other feelings, are all forged. We are voraciously social, loving creatures and no other creature strives to understand herself/himself as humans do.
So understanding love may be like understanding the universe. We may have to keep chasing to cover the expanding territory but the ride is just so much more satisfying and worthwhile if we get to try. – Rappler.com