Method acting is sometimes employed by certain actors to evoke realistic emotions into their performance by drawing on personal experiences. Raymond Hamden, a clinical and forensic psychologist, defines the purpose of method acting as "compartmentalizing their own feelings while playing another character [so] they could bring the emotions of that personal feeling to cry if they needed to with that character." However, when these emotions are not compartmentalized, they can encroach on other facets of life, often seeming to disrupt the actor's psyche. This occurs as the actor delves into previous emotional experiences, be they joyful or traumatic. The psychological effects, like emotional fatigue, comes when suppressed or unresolved raw emotions are unburied to add to the character, not just from the employing personal emotions in performance. The question becomes whether the actor calls up resolved or unresolved emotions in their acting. Psychological effects The psychological effects of method acting vary in intensity from individual to individual. Some common effects include: Fatigue Fear Anxiety Shame Irritability Sleep deprivation Personality changes Psychotic disorders Fatigue, or emotional fatigue, comes mainly when actors "create dissonance between their actions and their actual feelings". A mode of acting referred to as "surface acting" involves only changing one's actions without altering the deeper thought processes. Method acting, when employed correctly, is mainly deep acting, or changing thoughts as well as actions, proven to generally avoid excessive fatigue. Surface acting is statistically "positively associated with a negative mood and this explains some of the association of surface acting with increased emotional exhaustion." This negative mood that is created leads to fear, anxiety, feelings of shame and sleep deprivation. Raw emotion or unresolved emotions conjured up for acting may result in a sleep deprivation, anger, depression, anxiety and the cyclical nature of the ensuing side effects. Sleep deprivation alone can lead to impaired function, causing some individuals to "acute episodes of psychosis". Sleep deprivation initiates chemical changes in the brain that can lead to behavior similar to psychotic individuals. These episodes can lead to more lasting psychological damage. In cases where raw emotion that has not been resolved, or traumas have been evoked before closure has been reached by the individual, the emotion can result in greater emotional instability and increased sense of anxiety, sadness, fear or shame. The main psychological problems seen in method acting come from two facets of the emotional acting technique. The most well-known