Love, Lust and Neuroscience

I am the daughter of a retired florist. For me, Valentine’s Day conjures up memories of working in the family biz, packing and shipping hundreds (thousands?) of red roses to people’s sweethearts all over town. As a child, this was not a day I looked forward to. As a teenager, it was even less appealing. Needless to say, as an adult, Valentine’s Day is not my favourite. 

But I love the idea of doing something special for those you love, and I wanted to mark Valentine’s Day in a really neuro-nerdy way. What better way, I thought, than to do a little post here on the old blog-o about the neural basis of love. (I know, you’re thrilled. You’re welcome!)

I came across an fascinating article when I was researching this post, called “The common neural bases between sexual desire and love: A multilevel kernel density fMRI analysis.” They define love as “a state of intense longing for union with another.” I think that’s actually a great definition - it’s all about making a connection with another person. 

As the title states, the article is a summary of other papers which have used functional magnetic resonance imaging (fMRI) to see which areas of the brain are active when people experience love, and compare these to the areas which are active when people experience sexual desire. FMRI is a variation of regular MRI imaging - it’s different because it looks at blood flow, and how the oxygen levels change in the blood  that’s circulating around the brain. These changes in blood oxygen levels give researchers an idea of how active a certain brain region is, because regions that are more active use more oxygen. 

So pretty cool, right? People looked at some brains that were feeling lusty and some that were feeling lovey-dovey, and using the magic of fMRI, could pinpoint the love centre and the lust centre. But there is a hiccup. Although we have a motor cortex that plays a big role in helping us move around, and a visual cortex that processes the information our eyes take in, and an auditory cortex that does the same with noise, this article shows that there is no specific love cortex. There’s no special area of your brain that lights up when you’re with your beloved, or your kid, or your pet. 

Instead, they found patterns of activation - neural “networks” that lit up when people were feeling love both love and desire. And, most interestingly, they found that a significant overlap between the love and desire networks: an overlapping series of brain regions that are responsible for emotions, motivation, and cognition. Once again, the brain is not as simple as we might expect. Instead of one area, we have a series of areas that work together to produce the complex emotions and behaviours that make us human. The authors insightfully write, “love and desire are more than [basic emotions],” and both involve some major evolutionary functions, like courtship behaviour, choice of partner, and reproduction. 

So apparently, the circuit for emotions and pleasure are a part of the circuit for love. Perhaps we’ve piggybacked love and desire, with all their evolutionary benefit, onto failsafe networks that make us feel good. And that, my friends, sounds pretty good to me. Just make sure, if red roses are the way to light up your beloved’s neural networks, you buy local and support your hometown florist!