Scientists uncover Neurobiological basis for romantic love, trust, and self; also discover brain areas involved in understanding intentions of others
NEW ORLEANS, Nov. 10 – In new studies, scientists are discovering the neurobiological underpinnings of romantic love, trust, and even of self. New research also shows that a specific brain area – the amygdala – is involved in the process of understanding the intentions of others, in particular when lying is involved.
Using brain imaging, researchers Helen Fisher, Arthur Aron, Lucy Brown and colleagues find that feelings of intense romantic love are associated with specific activity in dopamine-rich brain regions associated with reward and motivation. Those study participants who expressed more romantic passion on a questionnaire showed more brain activity in these regions. Those in longer relationships showed more activation in emotion-related areas as well. And men and women tended to show some different brain responses. The researchers conclude that romantic love may be best classified as a motivation system or drive associated with a range of emotions. Further studies of intense, early stage romantic love may help to define how the brain encodes reward and memory.
In this experiment, 17 young men and women who had “just fallen madly in love” were tested with functional magnetic resonance imaging (fMRI) to identify the brain circuitry of romantic love.
“We believe romantic love is a developed form of one of three primary brain networks that evolved to direct mammalian reproduction,” says researcher Helen Fisher, PhD, of Rutgers University in New Brunswick, NJ. “The sex drive evolved to motivate individuals to seek sex with any appropriate partner. Attraction, the mammalian precursor of romantic love, evolved to enable individuals to pursue preferred mating partners, thereby conserving courtship time and energy. The brain circuitry for male-female attachment evolved to enable individuals to remain with a mate long enough to complete species-specific parenting duties.”
In the study, participants alternately viewed a photo of a beloved and a photo of a familiar, emotionally neutral individual, interspersed with a distraction task. The researchers hypothesized that intense early stage romantic love is: (1) primarily associated with dopamine pathways in the reward system in the brain; and (2) primarily a motivation system (as opposed to an emotion) oriented around planning and pursuit of a pleasurable reward – an intimate relationship with a preferred mating partner.
“Our evidence suggests that both hypotheses are correct,” says Lucy Brown, PhD, of the Albert Einstein College of Medicine in New York. “We found specific activity in regions of the right caudate nucleus and right ventral tegmental area. These brain areas are rich in dopamine and are part of the brain’s motivation and reward system. Elevated levels of central dopamine produce energy, focused attention on novel stimuli, motivation to win a reward and feelings of elation – some of the core feelings of romantic love. Activity in other regions changed also, including one that another imaging study has shown to became active when people eat chocolate.”
The researchers also found that those who scored higher on the “Passionate Love Scale,” a questionnaire administered prior to scanning, also showed more activity in the caudate. Arthur Aron, PhD, of SUNY Stony Brook, NY, says, “This result is among the first to show a direct link between responses to a survey questionnaire and a specific pattern of brain activation.”
Fisher, Aron, and Brown also found a tendency toward gender differences. Among them, most of the women in this study showed more activity in the body of the caudate, the septum, and posterior parietal cortex, regions associated with reward, emotion and attention; most of the men in this study showed more activity in visual processing areas, including one associated with sexual arousal.
Aron, Fisher and Brown have embarked on a follow-up fMRI study of men and women who have recently been rejected in love. They wish to understand the full range of brain systems associated with this primordial, powerful and universal human phenomenon.