Stephen Black wrote: > That doesn't say anything > about the relative percentages of auditory and visual > hallucinations, and PubMed surprisingly didn't turn anything up. > > Anyone have data?
According to a discussion by Heilbrun (1993): "Slade and Bentall (1988) offer a useful review of the evidence relating hallucinations to schizophrenia. Fifteen studies considered the percentage breakdown of schizophrenic patients experiencing the various types of hallucinations. Auditory hallucinations were found in about 60% of the schizophrenics on average (range 25%-94%) and visual hallucinations in 29% overall (range 4%-72%); auditory always prevailed in frequency over visual." (p. 58) The large range of these estimates makes me very curious: how were hallucinations being defined and measured in the various studies alluded to? In fact, earlier in the chapter, Heilbrun mentioned that different people use different definitions of "hallucination": "The true hallucination is limited by some to sensations that are believed to have their origins outside the body. The added awareness that the misperceived sensations are emanating from the individual's own body is treated as a 'pseudohallucination'." (p. 57) But I suspect that the studies examined by Slade and Bentall DO define and measure hallucinations in different ways, thereby resulting in different estimates. As for hallucinations in other modalities: "40% of the schizophrenics demonstrated tactile hallucinations, with gustatoty (18%), olfactory (17%), and somatic (4%) sensations less frequently observed." (Heilbrun, 1993, p. 58) If these estimates are to be believed, it appears that tactile hallucinations are more common than visual hallucinations. Perhaps a close examination of Slade & Bentall's would be worthwhile. Jeff References Heilbrun, A. B. (1993). Hallucinations. In C. G. Costello (Ed.), Symptoms of schizophrenia (pp. 56-91). New York: Wiley & Sons. Slade, P. D., & Bentall, R. P. (1988). Sensory deception: A scientific analysis of hallucinations. Baltimore: Johns Hopkins University Press. -- Jeffry P. Ricker, Ph.D. Office Phone: (480) 423-6213 9000 E. Chaparral Rd. FAX Number: (480) 423-6298 Psychology Department [EMAIL PROTECTED] Scottsdale Community College Scottsdale, AZ 85256-2626 Psychologists Educating Students to Think Skeptically (PESTS) http://www.sc.maricopa.edu/sbscience/pests/index.html The Psychology Student: Learning About The Science Of Psychology http://www.sc.maricopa.edu/sbscience/psychscience/index.html --- You are currently subscribed to tips as: [EMAIL PROTECTED] To unsubscribe send a blank email to [EMAIL PROTECTED]
