Though Steven Soderbergh has featured unknown, untrained actors in his movies in the past, he has raised a number of eyebrows recently by casting porn star Sasha Grey in the lead of his forthcoming feature ‘The Girlfriend Experience.’

To be sure, Grey is certainly outside of the mainstream of Hollywood actors, but she certainly is famous and has had quite a bit of experience on camera. Does Soderbergh consider her to be a true amateur?

“No, of course not, but the key is dealing with people who haven’t learned anything about acting,” he recently told MTV News. “She’s not trained and that’s what I’m looking for. She’s going to surprise people. She’s great in the movie.”

So that’s good to know! But what is “The Girlfriend Experience,” anyway?

“I was working with Brian Koppelman and David Levine and we were in a bar and I saw this woman on the other end of the bar and something wasn’t fitting. Her affect, the way she was alone, there was something that just drew your eye. What was going on there? This is not typical. Brian and David both said “GFE,” and I said “What’s that?” And they explained the girlfriend experience. They explained this whole world of high end escorts wherein its not just a straight sexual thing. It’s almost like a full on fake relationship. You go out to dinner and you talk and if you saw a transcript of it you’d think these people are in a relationship. I was really intrigued by that and we whipped up a story, a week in the life of somebody who does this.”

Given that Grey is experienced in having sex on screen, was Soderbergh tempted to have the actress perform unsimulated sex acts in the movie? No, says the director. “I guess I felt like that’s been done. That boundary has been broken. I don’t want that to distract. But I was looking for someone who was comfortable in scenes that were sexual. There’s a scene early on where she’s watching a guy get undressed and she’s standing there. She’s almost undressed already and the look on her face is fantastic. I don’t know how to describe it. She is absolutely in her element. That only comes from being in situations like that and being in control. She looks comfortable and in control. You can see it on her face. Its kind of awesome.”