It's quite possible that some of Ingmar Bergman's visceral yet outstanding works inspired Andrzej Zulawski's nerve-racking but impressive 1981 film, Possession. Here are my reasons why.
1. The monologue of two Annas. Zulawski's Anna talks about faith and chance, cancer, madness, and her dissolving love for her husband. Bergman's Anna discusses the man in her life, her relationship with that man, and a ghastly accident. They may not talk about the exact same thing but their monologues are somehow identical. These women invite us to look into their soul. Both also look at the camera as if they're talking to the audience.
Bergman film: The Passion of Anna (1969)