8 surprising sex truths: you may already know what turns you on, but we bet you're unaware of these naughty facts about yourself.

You probably have a pretty good grasp on your passion preferences. But a woman's sexuality is complicated--so tricky in fact that PhDs and other smarty-pants have devoted their careers to studying the titillating topic. To satisfy our never-ending curiosity about what's new on the sex-ed front, we decided to dig through their racy research and found eight fascinating facts that awed even us.

1 When you orgasm, your brain temporarily shuts down. During climax, the parts of women's brains that deal with alertness and emotions, including fear and anxiety, go inactive, according to Gert Holstege, MD, PhD, neuroscientist at the University of Groningen in the Netherlands. Just think, if you're able to shut your brain off before you even reach the peaks of pleasure, you'll be that much more apt to orgasm.

2 Women's number one fantasy is to surrender sexually to their man. "A number of studies have shown that the most common fantasy for females is to give in to their partner and have trim take charge sexually because it alleviates the constant pressure they feel to please their partner," says psychologist Michael Bader, author of Arousal: The Secret Logic of Sexual Fantacies.

3 When it comes to your pleasure, his package width matters most. The bigger the girth, the better able you are to feel him against the sensitive walls of your vagina. Plus the area where all the nerve endings are is only a few inches long, so anything more than ...