Scientists have identified a region deep within the brain that helps us decide who we fall in love with. But lust is controlled by an entirely separate part of the brain. The proof comes from a man whose damaged brain has lost the power to love.
The difference between love and lust is pretty clear for most people. Lust is all about short-term desire – you see a guy or girl you’re attracted to, and your thoughts fly ahead to sexual pleasure. You’re definitely not in love, and that’s something you know pretty much right away.
But for one 48-year-old man, understanding what it means to fall in love isn’t quite as straightforward. The cause? A stroke that damaged a region of his brain called the anterior insula.
Scientists already had a good idea that this part of the brain was involved in falling in love by studying images that show the brain regions that switch on during different activities.
Unable to love
These same studies also linked a separate part called the posterior insula to lust. They figured that because the man had damage to his anterior ‘love’ insula he wouldn’t be able to feel love in the same way as most people.
That’s just what they found. When they showed the man pictures of attractive women, he had no problem saying who he found sexy – his posterior ‘lust’ insula was in full working order. But when he was asked if he could feel love for the women, he had more trouble making up his mind – compared with other men it took him quite a bit longer to decide if love could be involved.
Concrete lust, abstract love
So how are love and lust processed differently in our brains? Lust is a definite physical drive – there’s no mistaking it when we feel it – and scientists believe it’s represented in a concrete way in our brains. Since the posterior ‘lust’ insula is also involved in physical sensations and helping us control our movements, it makes sense that this part of the brain should be linked to driving us to go after someone we’re sexually attracted to.
Love on the other hand is a more complex idea – it’s not as simple as short-term sexual satisfaction. Scientists think that it’s represented in a more abstract way in the anterior ‘love’ insula, which also plays a role in other feelings that involve making sense of emotions based on experience.