(CNN) -- At first, it was just a way for mental health professionals to treat their patients, but today, it's called "Outsider Art."
French artist Jean DuBuffet first coined the term "L'Art Brut," or literally "Rough Art," in the 1940s when he found psychiatric patients, children and prisoners with unusual artistic skill. The term stood for untrained artists "uncooked" by mainstream society.
It has since been translated to "Outsider Art," but it has also become much more elusive to define.
At the Outsider Art Fair in New York City, which starts this weekend, it means anything from drawings written on stationery from "State Lunatic Asylum No. 3," to calendars made of M&M wrappers and scraps of newspaper, to robots made from coffee pots, irons and sprinkler heads.
John Beardsley, an adjunct professor at the Harvard Design School, describes outsider artists as individuals isolated from the mainstream culture.
"DuBuffet said it's not only separate, but antagonistic to "cooked" culture. Purity always was, or used to be, a key concept," Beardsley said.
But Beardsley questions whether anyone can really be untouched by mainstream culture in today's world of Twitter, Facebook and YouTube.
"We all grow up touched by culture. Even back in the teens and 20s there was a traffic of images," says Beardsley. "It's only gotten more complicated and more compromised."
So what exactly is Outsider Art in 2011?
First founded in 1992, the Outsider Air Fair is held each February in New York City and now involves 26 dealers and hundreds of pieces of artwork. Stanford Smith, who first founded the show as an outgrowth of an American Folk Art fair, works closely with different dealers and galleries to find artists who are authentically "outsiders."
Smith defines outsider artists as "people on the outside of mainstream society, prison inmates, people who are autistic, people who live outside the boundaries of what normal people consider society."
Some of the artists featured are no longer alive, their artwork only discovered after their death. But many of the present-day artists have varying understandings of their own status as "outsiders."
The Fountain Gallery, part of a nonprofit that seeks to provide services and community for individuals with mental illnesses, brought their artist members to the fair. Gallery director Jason Bowman says artists have described their illnesses as "dangerous gifts."
"It's not something you would necessarily want, but it also brings extraordinary work," Bowman said.
Fountain Gallery artist BSpin, a 31-year-old woman dealing with mental illness, is exhibiting drawings depicting nude women and instruments. The unheard music of her pieces symbolizes her struggle with her illness. The "negative music" of her past made it difficult to be an artist. The vibrant colors and shapes of her current pieces are a celebration of the "positive music" present now.
For BSpin, the "outsider" label is a way for her to own what makes her different. "For me to be called outsider art is really kind of a badge of honor."
However, Keith Pavia, also of Fountain Gallery, feels very differently about being labeled as an outsider. Pavia is 44 years old and studied art at the Pratt Institute and the New York Studio School. He suffers from bipolar disorder.
"When you think of 'inside' you think of 'safe'," Pavia said. "As soon as you say 'outside' you think of the guy with the face pressed up against the glass, looking in. "
Pavia walks the line between mainstream and outsider status but feels comfortable in both. For Pavia, the goal is artistic expression that isn't self-conscious.
"What I respond to in outsider art, there's kind of a purity to it and I feel like a lot of the work that I see around here, people are channeling from a subconscious place," Pavia said. "It's something that I need to do to survive, it doesn't even factor in that I'm making art."
The Outsider Art Fair grapples with the changing definition of "outsider" but it also stays true to Jean DuBuffet's vision of Art Brut. The Christian Berst Gallery from France is featured in the fair exhibiting one of DuBuffet's original discoveries.
Henriette Zéphir is now 91, but in 1967 Jean DuBuffet literally begged her to have an exhibition of the drawings she had made as a spiritual medium. Christian Berst said Zéphir is still surprised when people tell her what she does is art.
"For her it has nothing to do with art, it has to do with a dialogue between her and her spirits," Berst said. "What makes this work so interesting is that it's not made for the market. It's the work from inside coming out."