By Mariella Careaga
Just like any other emotion, love has more to do with the brain than you might think.
Among all emotions, love seems to have a special place in the human psyche. Writers and filmmakers portray love as a maddening feeling that makes people euphoric, nervous, and irrational. There are iconic songs about love and how devastated we feel when we are not loved back. Though the unmistakable symbol of being in love is the heart, passionate love, as well as other emotions like fear and anger, finds its basis in the brain. Because of this, we should probably thank our brains (not our hearts) for falling in love.
The study of love, especially passionate or romantic love, gained traction during the 20th century. Back then, researchers, most of them psychologists, tried to understand the reasons why people fall in love and the factors that come into play when we choose a partner. That scenario changed drastically in the early 2000s when neuroscientists started to ask what the neuronal correlates of love are, as well as the neurochemistry behind it.
With Valentine’s Day just around the corner, we are going to explore the brain basis of romantic love. If you are interested in knowing more about the neurochemistry of love (and the cool research about it), check out our previously published story on this enigmatic feeling.
The brain activity of love
Our understanding of how romantic love impacts the brain expanded significantly when researchers looked at how people’s brains change when they see pictures of their beloved ones. By measuring brain activity using techniques like functional Magnetic Resonance Imaging (fMRI) and Position Emission Tomography (PET), scientists found that people in the early stages of romantic love (relationships of fewer than 3 years) show activation of many parts of the brain’s reward system — a group of structures that are activated when we experience something that is rewarding, such as eating a tasty food or hanging out with friends (Bartels and Zeki, 2000; Aron et al., 2005; Zeki, 2007). Love-induced activity in structures like the nucleus accumbens, striatum, and ventral tegmental area — all regions that mediate reward — could explain why many of us consider love a rewarding experience and is consistent with the idea that love is a ‘desire for union with another’ (Acevedo et al., 2012).
…people in the early stages of romantic love show activation of many parts of the brain’s reward system.
Researchers also found that love deactivates some brain regions. One of these areas is the prefrontal cortex, a structure important for reasoning and judgment. The decreased activity in the prefrontal cortex might explain why people in love seem to have a hard time honestly judging their loved one’s character (de Boer et al., 2012). Besides the prefrontal cortex, the amygdala also goes temporarily out of service when people are in love (Bartels and Zeki, 2004; Aron et al., 2005). The amygdala consists of a cluster of nuclei that processes fearful experiences and is involved in the formation of emotionally-charged memories. The deactivation of this area seems to reflect a reduction of fear that people experience when close to their beloved ones (de Boer et al., 2012; Zeki, 2007).
Though we might think of passionate love as an intense roller coaster of emotions, many long-time couples would describe their relationships as a calmer, less euphoric version of the early stages of love. Given that people can stay in love after decades of marriage, some researchers started to wonder whether long-term romantic love would share similar brain activity patterns with those seen in people who just fell in love.
In a study with 17 participants who were married for an average of 21 years, scientists found activation of brain regions associated with reward and motivation, similar to what was found in those who were newly in love (Acevedo et al., 2012). Unlike newly in love individuals, the brains of long-term partners showed activation in areas, like the globus pallidus, that have been linked to attachment and pair-bonding in monogamous rodents (Walum and Young, 2018). These results suggest that long-term passionate love shares similarities and differences with the early stages of romantic love (Acevedo et al., 2012).
…long-term passionate love shares similarities and differences with the early stages of romantic love.
An evolutionary role for love
Interestingly, neuroimaging studies have also shown that romantic love shares some commonalities with another form of love: that of a mother.
Both types of love activate overlapping areas in the brain’s reward system and deactivate regions associated with social judgment and negative emotions (e.g., prefrontal cortex and amygdala, respectively; Bartels and Zeki, 2004). The shared brain correlates between these two forms of love suggest that the adult attachment system evolved from the infant-caregiving one. This, in turn, supports the idea of an evolutionary purpose for both maternal and passionate love: to keep people together for a period of their lives in order to maintain and promote our species (Zeki, 2007).
From joy and infatuation to a giddy feeling, loss of appetite, and even sleeplessness, love can feel like a roller coaster ride. Though writers, poets, and musicians might tell us that love is a matter of the heart, it certainly has more to do with the brain. Yet, unlike any other emotion, the brain map created by love reflects a complex process that makes us desire, long for, seek and enjoy the company of our beloved.
Though writers, poets, and musicians might tell us that love is a matter of the heart, it certainly has more to do with the brain.
Written by Mariella Careaga
Illustrated by Mary Cooper
Edited by Caitlin Goodpaster, John Zhou, and Zoe Dobler
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Aron, A., Fisher, H., Mashek, D. J., Strong, G., Li, H., & Brown, L. L. (2005). Reward, motivation, and emotion systems associated with early-stage intense romantic love. Journal of neurophysiology, 94(1), 327–337. https://doi.org/10.1152/jn.00838.2004
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