One of the most overpowering themes of Alfred Hitchcock's cinematic masterpiece "Psycho" and Pink Floyd's musical masterpiece "The Wall" is the domineering figure of the "mother".
The Oedipus Complex or "Mother" complex. This occurs when a male child has an overpowering affection or fixation on his mother than transcends the natural boundaries and often overts incestual overtones, although not always.
In the case of "Pink" (The Wall), the overprotective matriarchal figure is very apparent, but lacks in the incestual themes. Pink's Mother shows the young boy her undying love even to the point of his insanity and refuses to let him face his fears. She constantly is referring to him as "baby" and shelters him from all the "nasty" dangers of the outside world thus helping him to "build a wall" which isolates him from the rest of society.
Mother is portrayed as a deitic or at least prophetic figure as young Pink constantly asks questions throughout his life expecting Mother to have all the answers.
But, rather than acknowledge she doesn't have all the answers, Mother proceeds to create nightmares for the boy about the world outside. She "puts all of her fears" into him. She filters the "dirty things" of the world from him to keep him "healthy and clean".
As Pink grows older, Mother "checks out" all his girlfriends. Pink eventually marries though, but as you'd expect, it doesn't last long. His sexual frustrations as released through lurid sexual behaviors and drugs. His total rebellion rips him from the arms of Mom physically, but he is still attached psychology as it becomes apparent that he cannot cope with the "dirty" world. He obviously attempts suicide, overdoses, lapses into paranoia and comes to the brink of madness. Eventually, the "wall" is torn down by the reasoning judge inside Pink's mind. He is apparently free of the "wall". Or is he? We never get the chance to find out, but rather are given a "moral" of sorts: "And when they've given you their all some stagger and fall. After all, it's not easy banging your heart against some mad bugger's wall." The case of Norman Bates is much like the case with Pink, but much more severe and doesn't have such a pleasant outcome.
Norman grew up with a domineering Mother also. Like Pink, his father died when he was a pre-pubescent child and was an only child. His love for his mother only grew into an attachment and later an obsession. The themes of "incest" are downplayed, but are prevalent in Norman's case as it leads him to severe sexual repression, insane jealousy, and even murder.
Norman's Mother, like Pink's, is a demanding and overshadowing figure never allowing Norman's psyche to grow up with his physical body. Norman will always be subject to her will, unlike Pink who, later, tore down his wall, Norman is forever trapped.
Unlike Pink, Norman's need for his Mother's attention becomes an addiction and instead of trying to escape, he indulges. When, Mrs. Bates finally meets another man, Norman is insanely jealous. His obsession leads him to rage and in a moment of insanity he kills both the man and Mother. This, however, doesn't free him.
When Norman realizes the terrible travesty he has committed, he loses it.
Norman is horrified that he actually took his Mother's life so he does everything to stop the pain and thought, including stealing her corpse from the funeral parlor, keeping her room exactly the same, and soon he begins to erase the very fact that Mother IS dead and he killed her. He begins to "give half of his life" to her to bring her back. The image eventually manifests in his mind and he develops a split personality able to converse and bond. His jealousy of her becomes balanced by his assumptions of her jealousy of him which leads him to murder women who sexually arouse him.
Norman is eventually caught and placed in an insane asylum. The dominant Mother personality has taken over completely. Instead of "tearing down the wall", as was Pink's case, Norman is "walled-in" forever.