A new study says that an instant attraction to someone is tied to a specific brain region.

Researchers at Trinty College in Dublin say that the medial pre-frontal cortex plays a major role in romantic decision-making by making a quick judgment about physical attraction within milliseconds of seeing a new face.

The study, which is in the Journal of Neuroscience, involved a speed-dating night and taking MRIs of people's brains. Researchers found the medial pre-frontal cortex region buzzed with increased activity when volunteers saw photographs of the people they'd later say they wanted to see again.