ROME — Bernardo Bertolucci has an intriguing take on how his upcoming 3D movie, “Io e Te,” about a 14-year-old boy who hides out in a Rome basement, might be placed within his oeuvre.As in “Last Tango in Paris” and “The Dreamers,” the new film touches on themes of claustrophilia (a love of enclosures) as opposed to claustrophobia, he says with an amused smile. Both “Tango” and “Dreamers” are largely set within Parisian apartments. “Io e Te,” is based on a short novel by Italo author Niccolo Ammaniti, best known outside Italy for “I’m Not Scared,” which was centered around a kidnapped child held captive in a cavern, and adapted for the bigscreen by helmer Gabriele Salvatores. Ammaniti specializes in characters who go back into their father’s womb, the famously Freudian Bertolucci says. While the confined space of the basement hideaway is where the young protag comes into close contact with his much older half-sister, who has a heroin problem, his attempt to save her prompts him to come out of his cocoon. Bertolucci is working on the “Io e Te” screenplay with Ammaniti and Umberto Contarello, who most recently co-penned Paolo Sorrentino’s Sean Penn-starrer “This Must Be the Place.” Meanwhile, he’s been testing two different 3D systems at Cinecitta Studios to “try to understand which one is the right system for this story.” Bertolucci decided to make “Io” in 3D after seeing “Avatar” in India. “I so loved the film. It reminded me of the 3D movies of the 1950s, which I’d seen as an adolescent,” he says. “I was thinking: ‘Imagine “8 1/2″ in 3D! Imagine Bergman’s “Persona” in 3D! I think they would be fantastic!’ And that immediately led me to think that there has been a kind of improper, or overly easy, use of this medium.” What Bertolucci loves about 3D is that “it’s based on the fact that you look with two eyes; so two cameras imitate that.” Casting is still not set on the pic, which will start shooting in Rome in September. The film, which will mark Bertolucci’s return to Italian-language feature filmmaking after a 30-year absence, will be produced by Rome-based Mario Gianani, who shepherded Marco Bellocchio’s “Vincere,” and by Bertolucci’s own Fiction Cinematografica shingle. Other production details, including foreign sales, are being kept under wraps.