Brie Larson is garnering a lot of praise (and even some very early Oscar speculation) for her role in "Room," the new drama, which premiered at the Telluride Film Festival in September and went on to receive the People's Choice Award at the Toronto Film Festival.
"It's brought up in a way that I feel like I'm on this marathon run and I have all these beautiful people on the sidelines handing me Gatorade," Larson, 26, told CBS News about hearing the positive feedback. "It's really cool. It's the highest honor you can receive in my profession. It's a wonderful conversation to be having. But I think what's more important to me is how deeply the film is actually resonating ... That's what I'm excited about."
Based on the 2010 best-selling novel by Emma Donoghue, "Room" tells the story of a young boy named Jack, who is being held captive in a small room along with his mother. Larson plays his mom, Ma, who was kidnapped and raped by her captor. The film, which co-stars Joan Allen and William H. Macy, follows what happens when they are let out of captivity as well.
"It's a very old story but told in a contemporary way ... I thought this was an amazing opportunity to show the more universal aspect of it and to get human beings to connect with it ... I also thought it was a way to make a comment on some of the interesting constructs that we've created for our society," Larson said about taking on the role.
Larson couldn't ever imagine what it would be like to have been held captive for seven years, but she tried to at least get into the mindset.
"I was on this restrictive diet with the help of a nutritionist and I was working out with a trainer every day. And I was speaking with a trauma counselor," she said. "The only aspect that I had a hard time wrapping my brain around was being in a confined space for seven years ... Like seven years later, what kind of acceptance has arisen from being there for so long? ... When you're given all this empty time in silence, what kind of stuff comes up?"
So she tried to "mirror" that silent room for a month: "I just pared everything down -- no cell phone and just basically stayed at home and the only time I did anything active was when I was doing these workouts."
In the end, staying largely silent for a month helped uncover some parts of her own past, Larson said.
"I was surprised to discover that I had some memories myself that were sort of similar to 'Room' -- in the metaphorical sense -- and it gave me incredible insight into another aspect of myself, which is why is I loved this project so much," said Larson who appeared in "Trainwreck" this year with Amy Schumer and also graced the big screen in "21 Jump Street" and "Don Jon."
Filming a movie with such dark overtones was made easier, thanks to Larson's 8-year-old co-star, Jacob Tremblay ("The Smurfs 2"), who plays her son, Jack. He brought an "innocence" and "light" to the set, she said.
"Making a movie is really hard and it takes participation and a lot of brain power of 100 people -- and something is bound to go wrong. There's a thousand things we need to get right in a day. It's easier to hang on to those things and to participate in the problem. But Jacob never does. Those things are never on his radar at all. Every day on set is just super fun and a chance to play and if you have to cry in a scene, that's super fun ... So we had this energy around that would bring this lightness to everything. Nothing would ever go too dark," Larson said.
And as for stepping into the mother role, Larson says it felt "effortless."
"Being a good actor is being a great listener and being very generous with your time and not making it all about yourself. It wasn't a giant leap for me to turn that energy toward an 8-year-old ... I found it to be a really helpful and humbling experience. Like when the entire day is getting his coverage first and my performance is secondary, I enjoyed that as a process. I didn't have all the time in the world to be super precious about myself."
"Room" begins opening in theaters on Friday. Watch the trailer below: