Carter, 47, will play the actress in upcoming mini-series 'Burton and Taylor' opposite Dominic West, who plays the star's on-and-off husband Richard Burton, reported Daily Star.
"The research is what I get off on. My mum is a psychologist and I'm very similar to her. I love the challenge of working a character out. Ultimately, I don't agree to do a film because I think it's going to be a success.
"I do it because I think I'm going to learn something from the character I'm playing. I'm not sure what yet, but I know I am going to learn something from Elizabeth. I know that, somehow, I'm going to grow as a soul from playing her," she said.
"There's less pressure on it. Which, of course, means I do it better. I take myself so much less seriously than I used to. I used to be so self-critical, it was painful. Now I think, 'OK, so I acted badly today. I'll try and act better tomorrow.' I mean, for God's sake, it's not like I'm a surgeon or anything. It doesn't really matter, does it?"
'Burton and Taylor' will air later this year.