Fassbender had already impressed film critics with his interpretation of one of the fathers of psychoanalysis, Carl Jung, in “A Dangerous Method,” also in competition at the Venice movie showcase. But it is his performance in Steve McQueen’s “Shame,” as a handsome executive living comfortably in Manhattan who can only escape his existential angst by seeking casual physical relations, that has made him the talk of the festival. “He’s a guy who is trying to feel something and then at the same time can’t involve himself emotionally with anybody,” Fassbender said. “He has this obsession (with) physical encounters that are pretty joyless and definitely nonemotional, and he is abusing himself, he doesn’t like himself.”