Norman Bates is shown at the beginning as am protagonist by being kind and helpful to Marion Crane
when she needs somewhere to stay, he even offers her dinner. The most interesting part of the movie is that he also has an antagonist side of him, which we see at the end of the movie when he is trying to attack Lila Crane dressed as his mother.
Hitchcock has influenced many horror films today with his techniques used in Psycho. Friday the 13th for example uses lighting and shadows to represent isolation when they are really alone and about to die. Alfred uses camera angle to show exaggeration and tension that is building up within the characters by getting close up shots. In Friday the 13th the angle of the cameras are precisely just like Psycho because they knew if it worked in Psycho it can be perfect in our movie as well.