A sensory perception in the absence of an external stimulus. Hallucinations are often differentiated from sensory illusions which are distortions or misinterpretations of actual sensory experiences. Hallucinations can involve any sensory modality (visual, auditory, tactile, olfactory, or gustatory).
Simple (unformed) hallucinations are sensory perceptions that are typically vague and without meaning (e.g., whistling sounds, flashing lights, geometric patterns). In complex (formed) hallucinations, the perceptual experience generally concerns objects, people, or animals (e.g., hearing voices, seeing animals, or tasting chocolate).
Psychosis (resulting from delirium or psychotic disorder)
Cerebral lesions (especially related to ictal discharge)
Amputation (phantom pain)
Certain dementias (e.g., Lewy body)
References and Readings
- Capruso, D. X., Hamsher, K. D., & Benton, A. L. (1998). Clinical evaluation of visual perception and constructional ability. In P. J. Snyder & P. D. Nussbaum (Eds.), Clinical neuropsychology: A pocket handbook for assessment (pp. 521–540). Washington, DC: American Psychological Association.Google Scholar
- Tenkin, S., & Cummings, J. L. (2003). Hallucinations and related conditions. In K. M. Heilman & E. Valenstein (Eds.), Clinical neuropsychology (4th ed.). New York: Oxford University Press.Google Scholar