Flat effect is a term used for describing the demeanor of an individual who, through depression or other mood disorder, displays little or no emotion while interacting with the world. More severe than "blunted affect" this can be a symptom of significant depression, an emotional numbness caused by stress or as a means of self-protection against the unpredictabilities of the world. It is also seen as a "negative" symptom associated with schizophrenia and related disorders. Brain scans have shown that individuals with flat affect display different profiles that healthy individuals. For instance, a person with flat affect might witness a car accident and show little reaction, while an emotionally healthy person might scream or faint.