The Neurobiology of Love

It’s that time of year, when love is in the air and on the minds of couples everywhere. But what exactly are these lovebirds thinking? Thanks to modern imaging, scientists are able to take a peek inside the besotted brain and show us what goes on during all stages of love—from lust to lasting relationship.

Head Over Heels in Love: A Natural Addiction

We tend to think of romantic love as an emotion, but it may be more of a survival instinct. Evolution has favored mechanisms that lead us to fall in love, because love increases the likelihood of an attachment that improves our chances of survival and provides more resources for child rearing. As neuroscientist Lucy Brown and cultural anthropologist Helen Fisher explain on their website, Anatomy of Love, “Romantic love is a drive, a motivation to win a preferred mating partner.”

As we fall in love, neural activity increases in key brain regions including the ventral tegmental area (VTA) located in the midbrain and the caudate nucleus found in each cerebral hemisphere. Both of these areas are part of the brain’s reward pathway. The VTA produces the “feel-good” neurotransmitter dopamine, which increases when we are hit by Cupid’s arrow.

Dopamine activates the reward pathway and gives us a pleasurable sensation similar to what we get from cocaine or alcohol, making falling in love akin to addiction. Meanwhile, the caudate nucleus appears to utilize its connections to the VTA and other brain regions to help keep the heart fluttering. Brown and Fisher postulate that the caudate nucleus integrates feelings, emotions and thoughts about your sweetheart to help kindle a romantic passion.

The phrase “love is blind” is quite appropriate during romantic love. Elevated passion can actually deactivate the neural pathway involved in negative emotions such as fear and social judgment. It also may flick off the switch in brain areas responsible for critical thinking, self-awareness, and rational decision-making, including parts of the prefrontal cortex. This neutralizing can make us act a little crazy when in the throes of a new romance.

Your Brain on Love: A Symphony of Hormones

The brain orchestrates our journey through the phases of love—lust, attraction, and companionship—by releasing specific hormones during each phase. During lust, the triggering of sex hormones testosterone and estrogen sparks physical attraction between a pair. We are taken into a deeper swoon of attraction by increases in dopamine and norepinephrine followed by a reduction in serotonin.

Dopamine and norepinephrine elevations can cause surges in energy and euphoria, common “symptoms” of falling in love. Reduction of serotonin is found in those with obsessive-compulsive disorder—a fitting shift for someone obsessed with a love interest.

The relationship progresses to the attachment phase through the release of oxytocin—called the “love hormone”— and vasopressin. Oxytocin increases in response to sexual activity and skin-to-skin contact, especially orgasm. This hormone helps reduce stress, and can also enhance a sense of trust and connection between two people. Release of vasopressin appears to foster protective behavior for one’s mate and family, which promotes long-term attachment. As Sue Carter, Director of the Kinsey Institute, noted in Psychodynamic Psychiatry, “While oxytocin may activate the more ‘passive’ aspects of attachment, vasopressin activates the more possessive, and in some cases more aggressive side of attachment.”Can a heady state of romantic love last?  Studies provide an optimistic answer for all the lovebirds out there, and neuroimaging helps confirm it. One study led by Bianca Acevedo, a research scientist at the University of California, Santa Barbara, compared brain images of two sets of participants: one group still deeply in love after being married an average of about twenty-one years, and one group that had just fallen in love. Functional magnetic resonance imaging revealed similar brain activity in the reward pathways of both groups, with high levels of dopamine in the VTA.

Beauty and Love: Allies in Happiness

Of course, there’s another kind of love that doesn’t require two people: the love of beauty in the arts and nature. “Why are flowers beautiful to us?” asked Ferris Jabr in “How Beauty Is Making Scientists Rethink Evolution,” his article in a 2019 issue of The New York Times Magazine. He noted that philosophers, scientists and writers over the centuries have attempted to answer the question by saying that beauty is “harmony; goodness; a manifestation of divine perfection; a type of pleasure; that which causes love and longing….”

Love of beauty may be part of the evolution equation. For example, our attraction to flowers may have originally been associated with their potential to bear fruit and grain, and thereby sustain us. Over time, our love of flowers appears to have transcended their intrinsic value; we find them beautiful regardless of their value to our survival. But the roots of that “unconditional love” may be in promoting our well-being.

What does art have to do with love? Famed neurobiologist and father of neuroaesthetics Semir Zeki investigated this topic in a number of landmark brain-mapping experiments. His discovery: looking at art elicits a pleasurable feeling similar to that of falling in love. In one experiment, he scanned the brains of volunteers as they were viewing twenty-eight works of art by legendary artists such as Botticelli, Monet and Constable. Dopamine production increased in the same areas of the brain as it does for people falling in love.

The Agony of Heartbreak…and the Possibility of a “Cure”

Brain scans shift dramatically after rejection by a love interest. A study reported in the Journal of Neurophysiology found that rejected lovers had significantly greater activity in the insular cortex, a region associated with distress and pain. The level of desperation can be severe and may worsen in the time following a rejection, similar to one’s experience after stopping use of an addictive drug. This is not surprising; there’s a positive association between the number of days after a breakup and increased activity in the right anterior cingulate gyrus, a region of the brain linked to cocaine craving.

Better understanding of the scientific basis of love opens new avenues to potential therapies for those suffering from the fallout of a failed relationship. Since how we feel after rejection can be emotionally debilitating and even painful, causing us to experience anxiety and depression, we may be able to treat it with traditional and integrative medicine. It has been shown, for example, that taking acetaminophen can reduce episodes of hurt feelings after rejection. Perhaps one day we will even be able to customize therapies to “mend a broken heart.”

Written and reported by IAM Lab Contributor Ed Decker.  Ed Decker is a freelance neuroscience writer and former Science/Health Editor at Rewire Me, a wellness website.

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