It is one of the most influential movies of all time. It has spawned countless rip-offs (see: any slasher movie), homages (see: any Brian De Palma movie) and tie-ins (see: three forgettable sequels and one pointless remake). It shocked contemporary audiences, not only with its graphic depictions of bloodshed, but also by (gasp!) showing a toilet flushing on-screen for the first time in movie history.

Alfred Hitchcock’s historic masterpiece, Psycho, which celebrates its 50th anniversary in June, is the subject of a new book by veteran film historian David Thomson (A Biographical Dictionary of Film).

The Moment of Psycho: How Alfred Hitchcock Taught America to Love Murder (Basic Books, 192 pages, $22.95) is a scene-by-scene analysis/deconstruction of the film, as well as an exploration of the movie’s significance in film history and its legacy as a pop culture phenomenon. Little did the legendary Hitchcock know when he directed Psycho, using much of the crew that worked on his “Alfred Hitchcock Presents” TV series, how revolutionary and iconic his modest, low-budget “B-movie” would become. Even those who have never seen the film know the general outline of the story, are familiar with the tragic tale of a shy, lonely, young motel owner named Norman Bates (played by Anthony Perkins in a career-defining performance) and his complicated relationship with his mother. (Funniest line in the movie: “Mother-m-mother, uh, what is the phrase? She isn’t quite herself today.”)

This was the kind of gruesome, psychologically disturbing tale audiences weren’t accustomed to when the movie premiered in June 1960. As Thomson notes, “[Psycho] was ahead of everything: We should never forget that it indulged sex (nakedness) and violence (that knife) and told censorship to get lost.” Psycho was also notable for its innovative structure in which the ostensible protagonist of the movie, Marion Crane (Janet Leigh), is abruptly killed off halfway into the movie, when she is stabbed to death while in the shower. This ingenious sequence, lasting only one minute in length, actually took a week to film. It is an expert example of editing and misdirection by Hitchcock, in that each “cut” by the knife translates to a “cut” in the film; therefore it is our mind’s eye that makes the sequence as bloody as it seems. (Actually, the viewer never sees the knife penetrating skin: The bloodshed is more implied than visualized, which makes it that much more terrifying.)

Thomson’s writing is punchy and concise, albeit a bit overly academic and highfalutin at times. However, it is difficult to argue with many of his points, including his observation that the film loses some steam after Marion is killed off (“The great difficulty facing Psycho is that our identifier in the film (Janet Leigh) is gone”), and that the second part of the film is “simply not worthy of the first half of Psycho.” At less than 200 pages, one also feels the book could be fleshed out a bit, with more space dedicated to the pre-/post-production of the movie. Yet, these are fairly minor quibbles. For the most part, The Moment of Psycho shows how pivotal the “moment” of Psycho truly was. As Thomson asks, “Is the moment of Psycho a true revelation of human nature or a threshold in filmmaking that says let violence run riot and to hell with the consequences?” Not only was Hitchcock’s masterwork unlike anything that came before it, but it also (despite many attempts) is unlike anything that came after.