Functional Magnetic Resonance Imaging (fMRI) brain scans of people in the early stages of romantic love show romantic love is less about emotions and more about rewards and the parts of the brain that control motivation.
BETHESDA, Md. (May 31, 2005) – You just can't tell where you might find love these days. A team led by a neuroscientist, an anthropologist and a social psychologist found love-related neurophysiological systems inside a magnetic resonance imaging machine. They detected quantifiable love responses in the brains of 17 young men and women who each described themselves as being newly and madly in love.
The multidisciplinary team found that early, intense romantic love may have more to do with motivation, reward and "drive" aspects of human behavior than with the emotions or sex drive. Brain systems were activated that humans share with other mammals. So the researchers think "early-stage romantic love is possibly a developed form of a mammalian drive to pursue preferred mates, and that it has an important influence on social behaviors that have reproductive and genetic consequences."
People in romantic love showed no consistent pattern of emotional activation in areas of the brain known to govern emotions. But they did show consistent activation of brain areas associated with motivation and goal-seeking mental states.
"Most of the participants in our study clearly showed emotional responses," noted Arthur Aron of the State University of New York-Stony Brook, "but we found no consistent emotional pattern. Instead, all of our subjects showed activity in reward and motivation regions. To emotion researchers like me, this is pretty exciting because it's the first physiological data to confirm a connection between romantic love and motivation networks in the brain.
"As it turns out, romantic love is probably best characterized as a motivation or goal-oriented state that leads to various specific emotions, such as euphoria or anxiety," Aron noted. "With this view, it becomes clearer why the lover expresses such an imperative to pursue his or her beloved and protect the relationship."
Romantic love happens in the basal ganglia region of the brain.
Aron reported that, using functional magnetic resonance imaging (fMRI) and other measurements, he and his colleagues found support for their two major predictions: (1) early stage, intense romantic love is associated with subcortical reward regions rich with dopamine; and (2) romantic love engages brain systems associated with motivation to acquire a reward.
Brown explains some of these findings, commenting that "when our participants looked at a photo of his/her beloved, specific activation occurred in the right ventral tegmental area (VTA) and dorsal caudate body. These regions were significant compared to two control conditions, providing strong evidence that these brain areas, which are associated with the motivation to win rewards, are central to the experience of being in love."
Brown noted that "an important concept is that the caudate probably integrates huge amounts of information, everything from early personal memories to one's personal notions of beauty. Then, this brain region (and related regions of the basal ganglia) helps to direct one's actions toward attaining one's goals. For neuroscientists," she said, "these findings about the diverse regional functions of the basal ganglia in humans have remarkable implications."
Romantic love happens on the right side of the brain while facial attraction happens on the left side.
Another important discovery, Brown said, was that "to our surprise, the activation regions associated with intense romantic love were mostly on the right side of the brain, while the activation regions associated with facial attractiveness were mostly on the left.
"We didn't predict such a striking lateralization," Brown reported. "It is well known that speech is largely a left-sided cortical function. But our data indicate that lateralization also occurs in lower parts of the brain. Moreover, different kinds of rewards (in this case, the "rush" of romantic love, compared with the pleasing experience of looking at a pretty or handsome face) is also lateralized. These results give us a lot to think about how the normal human brain learns and remembers and functions in general," Brown added.
Humans form attachments to each other using the same part of the brain that prairie voles use for pair-bonding.
Another breakthrough, Brown noted, was that "we found several brain areas where the strength of neural activity changed with the length of the romance. Everyone knows that relationships are dynamic over time, but we are beginning to track what happens in the brain as a love relationship matures."
Helen E. Fisher, a research anthropologist at Rutgers University, New Jersey, noted that not only did the brain change as romantic love endured, but that some of these changes were in regions associated with pair-bonding in prairie voles. The fMRI images showed more activity in the ventral pallidum portion of the basal ganglia in people with longer romantic relationships. It's in this region where receptors for the hormone vasopressin are critical for vole pair-bonding, or attachment.
"Humans have evolved three distinct but interrelated brain systems for mating and reproduction – the sex drive, romantic love, and attachment to a long term partner," Fisher said, "and our results suggest how feelings of romantic love might change into feelings of attachment. Our results support what people have always assumed – that romantic love is one of the most powerful of all human experiences. It is definitely more powerful than the sex drive."
People consider rejection in love as more important than rejection for sex.
For instance, Fisher point out, "If someone rejects your sexual overtures, you don't harm yourself or the other person. But rejected men and women in societies around the world sometimes kill themselves or someone else. In fact, studies indicate that some 40% of people who are rejected in love slip into clinical depression. Our study may also suggest some of the underlying physiology of stalking behavior," she added.
Fisher sees love as a product of natural selection.
"Darwin and many of his intellectual descendants have studied the myriad physiological ornaments that one sex of a species have evolved to attract members of the opposite sex, like the peacock's fancy tail feathers that attract the peahen," Fisher noted. "But no one has studied what happened in the brain of the viewer, the individual that becomes attracted to these traits. Our study indicates what happens in the brain of the viewer as he or she becomes physiologically attracted to these traits."
She added, "This brain system probably evolved for an important reason – to drive our forebears to focus their courtship energy on specific individuals, thereby conserving precious mating time and energy. Perhaps," she hypothesized, "even love-at-first-sight is a basic mammalian response that developed in other animals and our ancestors inherited in order to speed up the mating process."
What does the future hold for love? Greater knowledge of a phenomenon very often brings with it the ability to manipulate and control it. I expect the development of drugs and other treatments that cause people to fall in and out of love and to recover more easily from lost love.
Some people will choose to immunize themselves from love by using treatments that prevent the love process from developing in the first place. A person with history of heart breaks might decide that the possibility of a new love is just too painful to bear. Or someone who wants to devote their time to career might decide to innoculate themselves from the risk of romantic distractions. Still others of a more cerebral sort will decide that love is just a costly cognition distorting evolutionary vestige that they are best off without.
The ability to manipulate love medically will inevitably lead to misuse via surreptious reprogramming of the love state of others. Someone who wants to ditch their mate will be tempted to surreptitiously deliver medicine that will cause the mate to fall out of love. Or imagine the case where a suitor is rejected because the object of their love is in love with someone else. Inevitably some suitors will look for ways to surreptiously deliver a medical treatment that will cause the object of their love to fall out of love with someone else and thereby open up the possibility of forming a new love bond with them.
Motives also exist to cause people to fall in love with each other. This might be done by someone who has unrequited love for another. One can also very easily imagine members of couples (married or otherwise) using love potions to revive flagging marriages by returning their partner to an earlier state of love. But one can also imagine third parties (e.g. parents wanting to form a dynastic alliance of some sort) deciding to secretly do this as well.
The ability to surreptitiously cause people to fall in and out of love will inevitably lead to suspicions by those falling in and out of love. Can they trust their feelings as legitimate? Is pharmaceutically induced love less legitimate than natural love? If so, why? Will it be possible to develop technologies that check for unnaturally induced feelings of love?
Also see my previous posts "Love Deactivates Brain Areas For Fear, Planning, Critical Social Assessment", Hormone Levels Change When Falling In Love, and What Brain Scans Of People Falling In Love Tell Us.
|Share |||Randall Parker, 2005 May 31 11:29 AM Brain Love|