He completely looses himself in the image of his mother. He is so dissociated that he does not even know he is the one conducting the action of murder. Norman is "horrified to discover that his mother (actually his sub-personality) has stabbed a woman to death in the shower," (Comer 2003:224). To him, it was his mother, whom he has no control over. When he slips into that state Norman Bates disappears; he dissociates himself from a potentially harmful situation and allows the dominant personality of his mother take over completely. In the end, after all the trauma, Norman completely recedes into himself; "You see, when the mind houses two personalities, there's always a conflict, a battle. In Norman's case, the battle is over…and the dominant personality has won," (Hitchcock 160). His mother, who serves as his safety net, completely takes over when his psychosis...

Alfred Hitchcock is a master of suspense and with the character of Norman Bates shows the strange development of an abused boy isolated from reality in a terrifying and exciting plot line. His crimes and psychosis will forever live in movie infamy.
References

Comer, Ronald J. (2003). Abnormal Psychology. 5th ed. Worth Publishers

Freud, Sigmund. (1989). Civilization and its Discontents W.W. Norton & Co.

Hitchcock, Alfred. (1960). Psycho. Shamley Productions.

LeDrew, Stephen. (2009). Freedom and determinism: the uncanny in Psychoanalysis and existentialism. Psychoanalysis and Psychotherapy. Retrieved November 7, 2009 at http://www.psychoanalysis-and-therapy.com/articles/ledrew.html