Australian pop star Natalie Imbruglia has cast doubt on her acting ability - after admitting she struggles to play characters that differ from her. The singer, who appeared in long-running soap Neighbours and made her big-screen debut in comedy Johnny English in 2003, admits she's nervous about taking the lead role in new movie Elise - because her character Elise Silverton is a quiet and disturbed woman. She says, "I've got no idea if I'm going to be able to pull it off - it's a challenge. "It'll actually be very hard for me because it's quite a still performance and I'm quite over the top, loud and expressive." The movie, based on author Georgia Blain's novel Closed For Winter, deals with the story of a woman haunted by the disappearance of her sister 20 years before.