LOS ANGELES — Drawing on real neuroscience and the latest psychological research, "Inside Out" goes where no animated film has gone before: Deep inside the workings of a young girl's mind.

The much anticipated Pixar release, the studio's first in two years, bills itself as "a major emotion picture." Opening Friday, it centers on 11-year-old Riley, a happy, hockey-loving kid. Most of the action, though, takes place inside her head, where her staff of personified emotions — Joy, Anger, Sadness, Fear and Disgust — is in charge of operations.

When Riley is shaken by her family's move across the country, her emotions must navigate through her subconscious, dreams and memories to restore balance and protect her burgeoning personality.

It's not just heady territory for an animated family film. Experts say it's scientifically accurate and could expand popular understanding of human emotions.

"It really tells us something very true and unique about emotional experience," said psychology professor Dacher Keltner of University of California, Berkeley, an expert in the study of emotions who consulted with Pixar on the film and saw an early screening. "The film suggests that, in a way, all emotions have their purpose, and that is very much in line with the recent science."

Writer-director Pete Docter wanted to deeply understand the science behind such intellectual concepts as personality and memory before visually interpreting them on screen. He studied scientific papers and cross-checked story ideas with Keltner and other brain and behavior experts as he developed the film.

"I felt a pretty heavy responsibility (to accuracy)," Docter said. "It sort of stymied me for a while in making decisions. I remember sweating in my office, like... I don't know, what if I get it wrong?"

Pixar artists were tasked with imagining how to depict memories: How would they be kept and stored? How are they forgotten and where do they go? They dreamed up ways to represent intangible things like personality and the subconscious.

Ultimately, scientific accuracy took a backseat to story, Docter said: "We didn't want to do anything that would get us laughed out of the room, but we definitely stretched things and took some leeway."

In the film, Riley is upset when her family's move from Minnesota to San Francisco forces her to leave her best friend and her hockey team and start at a new school. Inside her head, Joy (Amy Poehler) normally reigns over the staff of emotions, but Sadness (Phyllis Smith) steps in after the move.

As Joy vies for control, she and Sadness get lost deep in the recesses of Riley's mind, leaving Fear (Bill Hader), Anger (Lewis Black) and Disgust (Mindy Kaling) at the helm. Riley appears angry and sullen to the outside world until Joy and Sadness make peace and return to their positions inside "headquarters."

Poehler called the film's take on emotions "a revolutionary concept."

"We tell ourselves that the constant pursuit of happiness is what we need to do, and if you're not doing it, you're doing something wrong," she said. "Instead, this big concept of feeling your feelings and trying to stay true to who you are and what you want, that's the journey. That's life, man!"

The story puts a premium on one girl's well-being, Kaling said.

"This is a big summer blockbuster movie, and the journey that she's going on is not to find a crystal necklace or an amulet or to kill a dragon or find a witch and do a riddle, it's just to be happy," she said.

Keltner, whose studies of emotion involve monitoring blood flow in the brain and measuring facial-muscle movements, said seeing the film's imaginative depictions of the mind, memories and feelings was "exhilarating."

"They have done a really faithful job in thinking hard within the constraints of the movie about what the science of emotion has revealed at the most fundamental level," he said. On the accuracy scale? "I'd give it a nine out of 10."

Producer Jonas Rivera characterized the film's approach as "like the greatest hits of mind theory."

"It's fun enough and whimsical enough that even the most devout scientist can see," he said, "if there are any inaccuracies scientifically, well, the emotions are also wearing pants."

Keltner believes the science it presents is accurate enough that the sweet story could influence how people feel about feelings.

"We denigrate the emotions, and this movie is going to say: Emotions are how we look at the world and they're how we relate to other people," he said.

It's "liberating" for kids to have these characters as a means for describing their feelings, said Poehler, who has two young sons. And she thinks it can be just as valuable for adults.

"When you're in a moment, you're so at street level," she said, "and this film gives you a bird's-eye view of what thoughts and feelings do to you, what they look like and what they want."

Making "Inside Out" changed Docter's perspective on human behavior.

"All these emotions are kind of programmed and act below your conscious threshold," he said. "Making a little more sense of this made me realize, in a way, to cut people a little more slack."

Follow AP Entertainment Writer Sandy Cohen at www.twitter.com/APSandy .

Online: http://movies.disney.com/inside-out/