Staring woman image via Shutterstock

You'd think watching pornography would be a turn on. But a new study suggests it actually causes part of the brain to turn off, at least in women.

A team of researchers from the Netherlands studied brain activity in 12 heterosexual, pre-menopausal women on birth control while they viewed "female friendly" pornography. As a control in the study, the women also viewed a non-sexual video about marine life in the Caribbean.

Using PET scans to measure brain blood flow, the team noticed that the primary visual cortex (the part of the brain that processes images) received less blood flow while women watched the most explicit porn, meaning this area was less active. When they watched the Caribbean marine life film, the blood flow to the visual cortex increased.

Researchers hypothesize that, when the body is aroused, women's brains may decrease blood flow to the visual cortex to direct blood to other parts of the body responsible for sexual arousal. Their brains "decided that focusing on arousal was more important than fixating on exactly what was occurring on the screen in front of them."

It turns out that watching porn is a relatively mindless act for women. "In other words," says Molly Oswaks at Gizmodo, "the porn goes on, the minds goes off."

No word on whether porn shuts down parts of a man's brain, as well.