Michelle Williams finds acting "liberating".

The 'Blue Valentine' actress admits she is shy in real life, and performing scenes she would never do in real life is a way of escaping herself.

She said: "I just find my work very liberating, and I find that I make allowances for myself, find space for myself and permission for myself in my work in a way that for some reason I don't in my life.

The 30-year-old actress - who has been nominated for a Golden Globe for her performance in 'Blue Valentine - stars alongside Ryan Gosling in the highly-anticipated Derek Cianfrance-directed romantic drama and admits living with him in preparation for the role was part of how they got into character.

She said: "When I say 'live' I do want to be clear that I didn't live THAT side of the marriage if you know what I mean, like after hours? l would go home every night, but yes, we inhabited the house like Dean and Cindy would or our imagination of Dean and Cindy would during the day.

"We actually made a house a home. I'm just thinking about that house now and it was nothing when we started and I feel like that's a place I lived now, like I would include that in my stops through life if I feel like it, "Oh, yeah. I lived outside of Scranton for a couple months."

'Blue Valentine' was put on limited release in the US on December 29 and hits UK cinemas on January 14.