The rush we feel when newly in love is not an emotion. It is a reward produced by ancient brain pathways that similarly motivate eating and drinking, according to a new, multi-institute study. The results indicate that during the intoxicating early stages of a relationship, “we are driven,” says Lucy L. Brown, a neuroscientist at the Albert Einstein College of Medicine and a co-author of the study. “The person we are in love with becomes a goal in our lives.”

Brown and her colleagues recruited 17 subjects who were 18 to 26 years old and had been smitten for one to 17 months. The researchers used functional magnetic resonance imaging to see how the subjects’ brains responded to a picture of their beloved, in contrast with an image of an acquaintance. For every lovebird, gazing at his or her sweetheart activated the unconscious neural system associated with reward, which arose early in mammalian evolution to encourage vital behaviors. Other neural activity varied; for example, some individuals who had been in love for more than eight months had stronger signals in cortical areas involved in cognition and emotion.

Brown concludes that early romantic love is not an emotion but a motivational state. The brain encourages an intense focus on the beloved through the reward system. Then, thanks to the many neural systems linked to our reward circuitry, we experience other feelings. “When you are in love, you can be anxious, happy, sad or angry,” Brown says, “but you still have a core feeling of loving the person.”

Eventually Brown would like to follow relationships that last for years, to understand what happens “when people form attachments and what goes wrong when people don’t,” she explains. In the meantime, her group is studying personal rejection by showing subjects a picture of a recent ex-boyfriend or ex-girlfriend, which Brown notes “is not so rewarding.”