For the first time, scientists have discovered how when we experience romantic love, the brain's behavioral activation system overrides other cognitive functions and suppresses external stimuli, prompting us to focus entirely on the other person. It's another step toward unraveling the mystery of attraction behavior that has baffled scientists (and, of course, all lovers).
Lead researcher Adam Bode from the Australian National University (ANU) said: "We actually know very little about the evolution of romantic love. So every discovery that tells us about the evolutionary history of romantic love is just the beginning of an important piece of the puzzle."
Researchers from the Australian National University, the University of Canberra and the University of South Australia (UniSA) assessed 1,556 young people who said they were "in love" with the aim of identifying chemical pathways and behavioral drivers to understand the way brain signals are triggered by a new, intense stimulus.
They studied the behavioral activation system (BAS), which is activated when experiencing positive emotions such as excitement and happiness. It can also motivate people to perform actions that may lead to rewards or achieve some beneficial goal. Previous research has shown that BAS sensitivity is associated with greater sexual arousal and excitement.
While the hormone chemical messenger oxytocin is most commonly associated with romantic love, researchers have discovered that BAS activity is the reason another person is able to become the center of another person's attention so quickly and prioritize the stimulation associated with it.
Phil Kavanagh of the University of Canberra said: "We know the role of oxytocin in romantic love because it circulates in our nervous system and blood when we interact with someone we love. Dopamine is a chemical released by the brain during romantic love. Essentially, love activates pathways in the brain associated with positive emotions."
But unlike one area of the brain being affected, BAS sensitivity affects a wide area. BAS sensitivity was associated with greater activity in the VTA-nucleus pathway and orbitofrontal cortex; BAS reward responsiveness was associated with greater activity in the lateral prefrontal cortex, anterior cingulate cortex, and ventral striatum. Meanwhile, BAS drive is associated with less activity in the brain's thalamus, caudate nucleus, and thalamus.
"Changes in gray matter volume in ventromedial prefrontal cortex and inferior parietal regions were also associated with BAS scale scores." The researchers noted: "There is also evidence that glutamate levels in the reward network contribute to individual differences in BAS reward reactivity. These structures generally overlap with those in romantic love."
Basically, one specific stimulus - a loved one - triggers global changes in the BAS throughout the brain, driven by oxytocin and dopamine activity, making this stimulus appear to be of higher value than all others. This is a complex mechanism, but can manifest itself in behaviors such as "putting someone on a pedestal" and daily life becoming completely dominated by new romantic love.
The researchers wanted to examine how male and female brains might have different pathways and BAS activity in their cognitive responses to romantic love. Functional magnetic resonance imaging studies can begin to isolate the specific contributions of BAS to romantic love intensity or specific characteristics of romantic love. , the significance of the research reported in this article goes beyond better understanding the mechanisms of romantic love. They also shed light on the evolutionary history of romantic love.
The study was published in the journal Behavioral Science.