Agyness Deyn has revealed how she was submitted to real medical tests for epilepsy as part of her research for new film Electricity.
The British model-turned-actress plays Lily, a young woman with epilepsy from a small northern town, who travels alone to London to search for her estranged brother, while trying to cope with controlling her condition.
Agyness revealed she was wired up to an EEG scanner to read her brain waves for real in scenes for the movie.
She said: "In the hospital the nurses were walking someone through how to do it and then Bryn [Higgins the director] said, 'Would you like to just do the procedure of what actually happens?'.
"Rather than us fabricating it, we actually did it, so I had all the tests.
"And that was one of my favourite scenes to film because it was just so freeing, it made me go into her and be her in the situation.
"It's such a delicate thing to go through those procedures. It just added to the reality of the whole thing."
But the 31-year-old Clash Of The Titans star admitted filming the physical scenes where her character has a seizure was very challenging.
Agyness confessed: "It was exhausting, it really was, and I really understood on a tiny, tiny scale how exhausting it must be. Because having to mentally get to a physical place, I had to be assertive to get there, but then someone with epilepsy they're not in control and they're basically being ridden to that. So it was only a fraction of the amount it really is for people with epilepsy.
"It was very tiring. But it was good for me to play Lily to have that exhaustion going on to have that reality of that speck of what it's like, because then you have some kind of reality of what it's really like."
The Manchester-born model - who changed her name from Laura Hollins - also admitted the role reminded her of when she first moved to the capital to start work as a model.
She revealed: "I was nearly 18 when I moved in, and it was so big, and coming from Manchester, it's so different. I did have that experience to draw on, and it did help me remember what it was like.
How big it is, and how loud it is and how hectic, and how impersonal it seems at the start. Even though Manchester is a city it's a lot smaller and the people are so different."
Agyness now lives in Los Angeles with her husband, actor Giovanni Ribisi, but admitted she does miss home.
"I miss it terribly, and more and more now," she said.
"When I was younger I was like, 'This is so exciting.' But now I miss my friends and family a lot.
"But more just English-ness, I can't describe it. Even the air and the people.
"I think it's just basically muscle memory and sensory memory of 'This is who I am, and this is where I'm from'."
Electricity is out in cinemas now.