Love or Lust?

By Medical Discovery News

Nov. 3, 2012

People seem to talk, sing, and write about love and lust more than any other emotions. Feelings behind love and sex give rise to intense emotions, and scientists have asked for years whether the feelings originate from one or separate structures in the brain. Most people can relate to relationships that made them wonder whether they’re in love or just in lust. Now evidence suggests love and sexual desire stimulate different but related parts of the brain.

Researchers in the U.S. and Switzerland pooled their brain imaging data from 20 studies to map areas of the brain that lit up as people viewed erotic images or pictures of their romantic partners.  Regardless of gender, two areas of the brain were triggered: the insula and striatum. The structures play a role in both sex and love, and provide evidence that first comes lust before love can follow.

For a person to realize they are feeling desire, the insula brings it to consciousness. Located inside the cerebral cortex, the insula connects the limbic system, which is a primitive emotion area of the brain, to the cortex, where the brain’s higher thinking takes place. By doing this, the insula creates awareness of feelings and attributes meaning to them.

The brain images also reveal that the back portion the insula is triggered by desire, the front by romantic feelings, and the middle portion is activated when people are with someone they both love and desire. As this is happening, the striatum is also triggered. The striatum, not far from the insula in the cortex of the brain, coordinates cognitive processes that include planning and executing pathways so that when a person is motivated to do something, they act. In this way, they can act on the object of their love and desire.

The striatum furthers this process with two other functions. It has reward pathways that are activated by sex and food, allowing a person to feel pleasure from these stimuli. Over time, as sexual pleasure continues with a person, the striatum’s other function of conditioning rewards this action and paves the way for sexual desire to progress to love.

Drug addictions trigger the same pathways, offering the first evidence to prove what people have always felt – that love is addictive. Put simply, love may be a habit that evolves from lust, as the desire is rewarded.

Love’s a good habit when it comes to partners, children or parents. Addiction to love is not as healthy, when a person is perpetually in new relationships and can’t sustain lasting bonds. While the new study suggests desire may be the precursor to love, it also shows love is more complex and abstract. It’s less dependent than lust on the physical presence of another person.

Love involves pathways of the brain responsible for monogamy and pair bonding, characteristics that many societies base their values on. More studies on understanding these emotions will lay the groundwork for further social neuroscience research.

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