updated 07/27/2009 AT 12:00 PM ET
•originally published 07/27/2009 AT 2:20 PM ET
Even the previews can be too much for Diaz. “You know what terrifies me? Trailers to horror movies!” she told PEOPLE while previewing her psychological thriller The Box at Comic-Con over the weekend. “I just can’t watch them. I hate horror movies. I’m always afraid.”
The actress especially can’t watch them at night, she adds with a shudder. “I kind of want to look, but I’m always afraid that I’m going to look too long and see the one image that I’m not going to be able to get out of my head for at least a week every night before I’m going to bed,” she said.
Fox, who stars in the sexy-gory scare-fest Jennifer’s Body, just avoids them altogether. “I don’t ever, ever watch scary movies because I have a very intense fear of the dark,” she said. “The last horror movie I saw, I think was called Tooth Fairy, and I was like 15 years old and I saw it and I slept with my mother for two weeks afterwards. I get really affected by them.”
Even her own movie gave Fox a good fright when she was recording extra dialogue for a scene in which the sound designers had already punched up her earlier screams. “I literally jumped and screamed inside the looping booth,” she said. “It frightened me and it shook me up for five minutes I was like, “Holy sh-t! That was really scary!”
There was something liberating in taking on a scary role, however. “For me to be able to play something that I would normally be frightened by was really intriguing and interesting,” said Fox. “It’s cool to see myself being able to scare people because I’m just a little girl.”