Toward a new definition of hallucination.

Two major flaws in the DSM-IV definition of hallucination are addressed: 1) it fails to distinguish pathological from nonpathological experiences; and 2) it fails to consider cultural beliefs in determining whether an experience is hallucinatory. These omissions are discussed within the context of an evolving concept of the term hallucination and an expanding vocabulary used to describe unshared sensory experiences. A revised definition is proposed.