The Science of Love

Forget Flowers!...Is Dopamine the main stimulus for Romantic Love? Charles Pasternak explores the claims Helen Fisher makes in her new book "Why We Love: The Nature and Chemistry of Romantic Love".

We mark the 14th of February as St Valentine's Day - a lovers' festival since the 14th century. Quite what a priest named Valentine, who suffered martyrdom in Rome during the 3rd century, had to do with love is not at all clear; if you look up St Valentine in the New Encyclopaedia Britannica you will find reference only to the massacre, by Al Capone and his cronies, of unarmed members of a bootlegging gang in Chicago on the 14th of February 1929. Never mind. Love is what makes the world go round, according to the 19th century French song, and this is as good a time as any to consider just what the feeling of love really is.

Emotions like love are, according to clinical neurologist Antonio Damasio, 'neither intangible nor elusive. Contrary to traditional scientific opinion, feelings are just as cognitive as other percepts. They are the result of a most curious physiological arrangement that has turned the brain into the body's captive audience ... To discover that a particular feeling depends on activity in a number of specific brain systems interacting with a number of body organs does not diminish the status of that feeling as a human phenomenon. Neither anguish nor the elation that love or art can bring about are devalued by understanding some of the myriad biological processes that make them what they are. So what does Helen Fisher tell us about the science of love in her latest book "Why We Love: The Nature and Chemistry of Romantic Love"?

The crux of her argument is that hormones circulating in the brain are the trigger:

"...this fire in the mind is caused by elevated levels of either dopamine or norepinephrine or both, as well as decreased levels of serotonin."

She supports her hypothesis by mapping the areas of the brain that 'light up' by fMRI (functional magnetic resonance imaging) when subjects who are passionately in love are shown pictures of their adored one. The technique of fMRI is essentially a scientific follow-up to the well-known reaction we all experience when a personal comment gets too close: we blush. The reddening of our face is due to increased blood flow below the skin; fMRI localises areas of increased blood flow in the brain when certain bundles of nerve cells respond to a particular stimulus: raising an arm, being confronted by a frightening situation, concentrating on a difficult mathematical calculation. Dr Fisher's contention is that regions of the brain (the caudate nucleus and ventral tegmental area in particular) in which the main chemical responsible for nerve transmission is dopamine, are the ones that respond to the stimulus of romantic love.

In order to recruit appropriate subjects to place inside an MRI machine, Helen Fisher and her colleagues at the State University of New York (SUNY) on the Stony Brook campus advertised for students who had 'just fallen madly in love'. Once inside the machine, they were shown a series of photographs (through an arrangement with mirrors: the entire head is within the machine). Some photographs were neutral, others were of their adored one. Between each picture the brain was cleared of emotional responses by asking the subject to mentally count backwards in increments of 7 from a large number like 4,673.