Tom Allaway wrote: > I have a student interested in whether a hypnotically induced > perception of an auditory stimulus could be demonstrated to mask an > actual stimulus. Does anyone know of relevant work?
Max Gwynn, who has performed research on hypnosis, probably could answer your question (in fact, he responded while I was writing this); but please allow me--a nonexpert who likes to make use of opportunities such as this to learn more about various topics--to very briefly summarize a review by Nicholas Spanos (1996) of research on "negative hallucinations." The research on negative hallucinations seems relevant to the question you're asking even though it focuses on a somewhat different problem. The concept of "negative hallucination" refers to "the idea that highly responsive hypnotic subjects can be made to suffer some profound sensory loss (e.g., deafness, blindness) through suggestion." (p. 30). Hypnotically induced deafness or blindness is inferred in many studies from the fact that subjects fail to respond to auditory or visual stimuli, or report that they are unable to sense the stimuli. As Spanos noted: "The problem with inferring impairments in hearing or vision in these studies is fairly obvious. Suggestions for deafness and blindness tacitly instruct subjects to behave as if they are deaf or blind. Consequently, subjects who hear and see quite well, but are motivated to present themselves as 'hypnotized', may report their hearing or vision as impaired or engage in other voluntary behaviors (e.g., consciously suppress startle responses to 'unexpected' noises) that convey the impression of deafness or blindness." (p. 30) Thus, any study that examines hypnotically induced changes must include controls for demand characteristics of the study. In other words, one must measure behaviors that are not under the voluntary control of subjects. For example, delayed-auditory-feedback (DAF) studies test hypnotic deafness by having subjects listen to a recording of their voice reading a story while they simultaneously attempt to read the same story out loud. Spanos stated that, "when a slight delay is introduced between what subjects are reading and what they are hearing, subjects with normal hearing [but who have been given a suggestion for hypnotic deafness] begin to pause, stammer, and stutter. Deaf subjects, of course, are not affected by DAF." (p. 31) According to Spanos, studies that measure behaviors not under the voluntary control of subjects tend to find little or no evidence for hypnotically induced deafness or blindness. He concluded that the positive results reported in poorly controlled studies were due to subject compliance. Jeff Reference Spanos, N. (1996). Multiple identities and false memories: A sociocognitive perspective. Washington, DC: APA. -- 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]
