Why can we make disastrous decisions in love?

This is your brain on love - more neuroscience!

Her front brain is telling her he's trouble. Look at the facts, it says. He's never made a commitment, he drinks too much, he can't hold down a job.

But her middle brain won't listen. Man, it swoons, he looks great in those jeans, his black hair curls onto his forehead so adorably, and when he drags on a cigarette, he's so bad he's good.

His front brain is lecturing, too: She's flirting with every guy in the place, and she can drink even you under the table, it says. His mid-brain is unresponsive, distracted by her legs, her blouse and her come-hither stare.

Alas, when it comes to choosing mates, smart neurons can make dumb choices. Sure, if the brain's owner is in her 40s and has been around the block a few times, she might grab her bag and scram. If the guy has reached seasoned middle age, he might think twice about that cleavage-baring temptress. Wisdom - at least a little - does come with experience.

But if the objects of desire are in their 20s, all bets are off.

It's a dance that holds many mysteries, to psychologists as well as to the willing participants. Science is just beginning to parse the inner workings of the brain in love, examining the blissful or ruinous fall from a medley of perspectives: neural systems, chemical messengers and the biology of reward.

It was only in 2000 that two London scientists selected 70 people, all in the early sizzle of love, and rolled them into the giant cylinder of a functional magnetic resonance imaging scanner, or FMRI. The images they got are thought to be science's first pictures of the brain in love.

The pictures were a revelation, and others have followed, showing that romantic love is a lot like addiction to alcohol or drugs. The brain is playing a trick, necessary for evolution, by associating something that just happened with pleasure and attributing the feeling to that magnificent specimen right before your eyes.

Somehow, it all comes together, for better or for worse, the sum total of what's found in the mating dance of the ancient reptilian brain, the passion of the limbic brain and the logic of the neocortex; and, if you want to know how this translates into your money behaviour read 'Money, Money, Money Ain't it Funny.'