Well, we might not be able to prove 'love at first sight', but hopeless romantics out there can defend their belief in long-lasting true love - physiologically.
Cynics and single girls tend to argue that love fades in a relationship, and married couples don't really feel the same way about each other as they once did. Well, that's not necessarily true.
A new study, presented at the annual meeting of the Society for Neuroscience, has found that couples that have been together for a long time and claim to be "madly in love" still actually are, at least as far as brain scans can tell.
Most couples who have been together for a long time feel a shift in the relationship from an energetic, passionate love to one more subtle and comfortable. But the researchers noticed a group that seemed to break the mold - they claimed to be just as passionate as ever. In 2005, a study used fMRI scans to show that a particular part of the brain, the ventral tegmental area, was activated while people who had been in love for a relatively short amount of time (less than seven months) looked at images of their partner. The ventral tegmental area is also activated by cocaine, and is the region that controls production of the natural stimulant dopamine, just FYI.
So to see if the long-term couples really were as madly in love as they once had been, researchers monitored the subjects' brain activity using fMRI while they looked at images of their sweethearts. People who have been madly in love for an average of 21 years had the same activation in that area of the brain associated with the 'honeymoon stage' - the ventral tegmental area.
At the same time, there were key differences between the young couples and the long-lasting bonds that might reveal why some relationships might last. The couples that were freshly in love also showed activation in a part of the brain associated with obsession and anxiety whereas the couples in for the long haul showed activation in areas associated with calmness and pain suppression.
“The difference is that in long term love, the obsession the mania, the anxiety has been replaced with calm,” says coauthor Helen Fisher, a biological anthropologist from Rutgers University, in a news conference.
So if you believe that love can be long-lasting and true, well, you're right. Perhaps we shouldn't let too many people know about this study, though. I can see it now. "Honey, you don't really love me!" "Yes I do Sweetie." "Oh yeah? Prove it! Let me see your brain scans!"