The mind-opening concept behind Pixar's new comedy Inside Out

Everyone's got them, but the movie Inside Outmight be the first family-friendlyfeature aboutthe voices in our heads.

The new computer-animated comedy from Disney/Pixarhittheatres this weekend, taking audiences on a journey through the inner workings of a young girl's mind.

• FILM REVIEW |Inside Out: A 'truly powerful' look into the mind of an 11-year-old girl

The studio's adventurous new projectis the brainchild of director and screenwriterPete Docter, who was inspired by his own pre-teen daughter's emotional transformation.

'What's going on inside her head?'

"She was young, spunkyand energetic, and then she turned 11 and she became much more quiet and subdued," Docter told CBC News.

"All that childhood joy went away and I asked, 'Whoa, where did that go? What's going on inside her head?'"

Inside Outcentres on a happy-go-lucky 11-year-old named Riley Anderson who is thrown for a loop when her family moves fromMinneapolis toSan Francisco.

Livingin colour

But the real action takes place inside Riley's pre-teen mind wherea cast of colourful characters personify herfive primary feelings as she adapts to the change.

• Joy, voiced by comedianAmy Poehler
• Fear,portrayed bySaturday Night Live'sBill Hader
• Anger, aspersonified by the ranting funnymanLewis Black
• Disgust, played byThe Mindy Project'sMindy Kaling

Thecerebral and melancholy feeling ofSadness is voiced byThe Office's Phyllis Smith, whoadmits she waspetrified when she first started onthe project.

It turned out that her own insecurities and fears actually worked toher advantage.

"When I gained more confidence, it also helped with the evolution of Sadness," said Smith, who described the challenge of having to delivera single line five or six differentways. But she knew that she got it right when she'd hear laughing from the control room.

• VIDEO |Inside Out: The evolution of Sadness

"Even though they're in the booth and you're not supposed to hear anything, if you hear the giggle you go 'ok, I'm on the mark,'" says Smith.

"If they're giggling, I'm happy with it."

Professional help

Despite the humour, the film's producers didn't take the depiction of emotional metaphors lightly. They consulted with two psychologists, including emotionalresearchpioneerDr. Paul Ekman, who helped them create accurate depictions ofthe sophisticated human mind.

"[Ekman]was the one who pointed out that there are these multiple systems at work," explainedDocter.

"We like to think of ourselves as the decision maker ... but there are other things at play, like what you were raised with andall this back history that you may not be conscious of."

Docter says working withEkmanevenchanged the way he sees himself and hehopes that the audience will find the film enlightening, too.

Thefruits of their labour appear to be paying off. Some Pixar families saw early screenings of the film and reported an impact on their kids.

One employee said hisson suddenly overcame his long-heldfear ofthe high diveat his localpool afterseeing the film.

• VIDEO|Inside Out's director describes the personal inspiration for the film
• How Pixar changed Disney Animation from within
• Toy Story 4 announced by Pixar for 2017

"He told his dad that he realized fear was driving him and he pushed it out of the way," explained Rivera. "He applied the film to his living and his thinking and that was really moving to us."

Inside Out is in theatres now.

Watch interviews with director PeteDocter,producerJonasRivera and actressPhyllis Smith in the videos above.