Love: What′s the Brain Got to Do With It?
Publication Date: 2/11/2010
For centuries, humans have been plagued by the mysteries of love and heartache. What do we really know about this thing we call love, and what can neuroscience—a study of how the brain affects behavior—tell us about the feelings we associate with love?
Dr. Kim Gerecke, assistant professor of psychology, says, “Traditionally, neuroscience hasn’t focused on big meta-phenomena, such as love. However, recently, with the advent of functional MRI, we can actually look at changes that are taking place in the brain.”
Over the past few decades, scientists have been studying pair bonding in mice and voles. They began to wonder if their work could be translated to humans through neuroimaging. Professor Gerecke explains, “They put a person in a functional MRI, and they look for specific brain regions to see if these areas are active under conditions where someone is thinking about their partner versus when they’re thinking about their friend or their child.”
Gerecke says there are similarities observed in both the animals and humans studied. “In animals, maternal love and bonding activates pathways that use hormones called oxytocin in females and vasopressin in males.” She explains, “These two hormones, which have traditionally been thought of as bonding hormones in animals, also appear to contribute to bonding in humans, as research has indicated that those same neural substrates are activated in humans when experiencing love.”
Further evidence of this connection lies in animal mating, a sexual behavior initiated by estrogen in females and testosterone in males. “If you look at people who are in crazy, mad love, that early stage of lust, you’ll see a lot of circulating levels of estrogen in females and testosterone in males,” Gerecke states.
In looking at different types of love--such as the initial attraction of lust versus long-term, comfortable love or partnership bonds--there are some activated parts of the brain that are similar and some parts that are different. Gerecke, who also teaches a course on drugs and the brain, asserts, “That initial crazy, mad love is actually mapping on to parts of the brain that deal with addiction. If you look at the brain, it’s similar to how people behave when they’re craving drugs or under the effects of drugs. The quote, ‘love is a drug,’ is accurate when you look at the brain.”
However, when people are under the influence of calmer, long-term love, most of the addiction part begins to decrease. Crazy lust settles into something more comfortable and less passionate. Gerecke says, “In that case, we see less of the addiction pathway coming up and more of those bonding pathways of oxytocin and vasopressin. When you look at the brain, you can see this change in the neural substrates, and that maps very nicely onto the change in subjective feeling that people respond to.”
The road from mere observation to the application of these ideas is controversial, according to Gerecke. However, she points out, “It is intriguing to see that the way we think about these things from a philosophical standpoint and the way that we feel them are reflected in differences in brain activity.”
(information compiled by Rhodes Student Associate Brianna McCullough ′10)