For the first time, scientists have uncovered how the brain's Behavioral Activation System can override other cognitive functions and subdue external stimuli when we experience romantic love, driving that all-consuming focus on the other person. It’s another step towards unlocking the behavioral mystery of attraction that continues to stump scientists (and, let's face it, everyone else).
“We actually know very little about the evolution of romantic love,” said Adam Bode, the lead researcher from the Australian National University (ANU). “As a result, every finding that tells us about romantic love’s evolution is an important piece of the puzzle that’s just been started.”
Researchers from ANU, the University of Canberra and University of South Australia (UniSA) have assessed 1,556 young adults who identified as being ‘in love’ to find the chemical pathways and behavioral drivers that inform the way the brain’s signals are triggered by one new powerful stimuli.
They looked at the Behavioral Activation System (BAS), which fires up in response to experiencing positive emotions like excitement and happiness. It also motivates behavior that could receive a reward or reach some sort of beneficial goal. Previous studies have linked BAS sensitivity with stronger sexual arousal and excitability.
While hormonal chemical messenger oxytocin is most often associated with romantic love, the researchers found that BAS activity was responsible for how another person could so quickly become the center of someone’s attention, prioritizing stimuli associated with them.
“We know the role that oxytocin plays in romantic love, because we get waves of it circulating throughout our nervous system and blood stream when we interact with loved ones,” said Phil Kavanagh, from the University of Canberra. “The way that loved ones take on special importance, however, is due to oxytocin combining with dopamine, a chemical that our brain releases during romantic love. Essentially, love activates pathways in the brain associated with positive feelings.”
But unlike one area of the brain being impacted, BAS sensitivity has widespread reach. BAS sensitivity has been linked to more activity in the VTA–nucleus accumbens pathway and the orbitofrontal cortex; and BAS reward responsiveness has been linked to more activity in the lateral prefrontal cortex, anterior cingulate cortex, and ventral striatum in the brain. Meanwhile, BAS drive has been associated with less activity in the putamen, caudate, and thalamus.
“Variation in regional gray matter volume in the ventromedial prefrontal cortex and inferior parietal lobule has also been associated with BAS Scale scores,” note the researchers. “There is also evidence that reward network glutamate levels contribute to individual differences in BAS reward responsiveness. The structures generally overlap with those found in romantic love.”
Essentially, a specific stimuli – the loved one – results in the BAS triggering wholesale changes across the brain, fueled by oxytocin and dopamine activity, that results in this one stimuli seemingly valued above all others. It’s a complex mechanism, but manifests in behaviors such as putting a person ‘on a pedestal’ and having daily life completely consumed by a new romantic love.
The researchers now hope to study how the male and female brain 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 contribution of the BAS to the intensity of romantic love or specific features of romantic love,” the researchers said. “The implications of the studies reported in this article extend beyond a better understanding of the mechanisms of romantic love. They also provide insights into the evolutionary history of romantic love.”
The study was published in the journal Behavioural Sciences.
Source: University of South Australia
