New York City is preparing to test the idea that art is a universal medium by commissioning artists to paint murals that would raise awareness about mental health. The plan comes with a unique catch: each of the artists has to enlist 30 to 40 people from community-based mental-health programs to help with the project. The project is modeled after the Porch Light Project in Philadelphia, which a study found helped curb discrimination against individuals with behavioral disorders or addictions.