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.