In psychology,<unk> is a treatment or process that diminishes emotional responsiveness to a negative, aversive or positive stimulus after repeated exposure to it.<unk> also occurs when an emotional response is repeatedly evoked in situations in which the action tendency that is associated with the emotion proves irrelevant or unnecessary. The process of<unk> was developed by psychologist Mary Cover Jones, and is primarily used to assist individuals in unlearning phobias and anxieties. Joseph Wolpe (1958) developed a method of a hierarchal list of anxiety evoking stimuli in order of intensity, which allows individuals to undergo adaption. Although medication is available for individuals suffering from anxiety, fear or phobias, empirical evidence supports<unk> with high rates of cure, particularly in clients suffering from depression or schizophrenia.
Desensitization 
Sensitization 
Cross-tolerance
Reverse tolerance
Co-stimulation
Central tolerance
Counterstimulation
Priming 