United Kingdom, June 16 -- Emma Heming Willis says Bruce Willis' frontotemporal dementia (FTD) doesn't affect his memory.

The Die Hard actor's family revealed his FTD diagnosis three years ago, and now his wife of 37 years has explained there is a big misconception about the disease, which has "three different variants".

She told the Bossticks podcast: "The one that Bruce has affects language.

"But there's another variant that will affect behaviour and another one that could affect movement."

The 71-year-old star has daughters Mabel, 14, and Evelyn, 12, with his 47-year-old wife, as well as Rumer, 37, Scout, 34, and Tallulah, 32, with ex-wife Demi Moore.

Emma added: "That's a different part of the brain. So when people say, 'Oh, does...