Hallucinations are false or distorted sensory experiences that seem real and may be seen, heard, felt, and even smelled or tasted, yet are generated only by the mind.

A hallucination occurs when a misfire occurs within the mechanism of the brain that helps to distinguish conscious perceptions from internal, memory-based perceptions. This can be caused by stress, medication, extreme fatigue, mental illness, or other environmental, emotional, or physical factors. Hallucinations occur during periods of consciousness. They can take the form of visions, voices or sounds, tactile feelings (touch), smells, or tastes.

Patients suffering from dementia and psychotic disorders such as schizophrenia frequently experience hallucinations. Hallucinations can also occur in patients who are not mentally ill as a result of stress overload or exhaustion, or may be intentionally induced through the use of drugs, meditation, or sensory deprivation. Almost 40% of people are known to experience hallucinations as they are...