Suggested visual hallucinations in and out of hypnosis

University of Hull, Department of Psychology, Cottingham Road, Hull HU5 3EY, United Kingdom.
Consciousness and Cognition (Impact Factor: 2.31). 04/2009; 18(2):494-9. DOI: 10.1016/j.concog.2009.02.002
Source: PubMed


We administered suggestions to see a gray-scale pattern as colored and a colored pattern in shades of gray to 30 high suggestible and eight low suggestible students. The suggestions were administered twice, once following the induction of hypnosis and once without an induction. Besides rating the degree of color they saw in the stimuli differently, participants also rated their states of consciousness as normal, relaxed, hypnotized, or deeply hypnotized. Reports of being hypnotized were limited to highly suggestible participants and only after the hypnotic induction had been administered. Reports of altered color perception were also limited to high suggestibles, but were roughly comparable regardless of whether hypnosis had been induced. These data indicate that suggestible individuals do not slip into a hypnotic state when given imaginative suggestions without the induction of hypnosis, but nevertheless report experiencing difficult suggestions for profound perceptual alterations that are pheonomenologically similar to what they report in hypnosis.

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    • "Indeed, the difference between the number of suggestions that high suggestible participants respond to with or without hypnosis is small (Braffman and Kirsch, 1999; Kirsch and Braffman, 2001) and abilities thought possible only following a hypnotic suggestion can be achieved without hypnosis (e.g. colour hallucination (Mazzoni et al., 2009), Stroop effect reduction (Raz et al., 2006; Raz, 2007)). Low suggestible people on the other hand do not seem to be capable of demonstrating these abilities whether a hypnotic induction is attempted or not. "
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    ABSTRACT: This study explores whether self-reported depth of hypnosis and hypnotic suggestibility are associated with individual differences in neuroanatomy and/or levels of functional connectivity. Twenty-nine people varying in suggestibility were recruited and underwent structural, and after a hypnotic induction, functional magnetic resonance imaging at rest. We used voxel-based morphometry to assess the correlation of grey matter (GM) and white matter (WM) against the independent variables: depth of hypnosis, level of relaxation and hypnotic suggestibility. Functional networks identified with independent components analysis were regressed with the independent variables. Hypnotic depth ratings were positively correlated with GM volume in the frontal cortex and the anterior cingulate cortex (ACC). Hypnotic suggestibility was positively correlated with GM volume in the left temporal-occipital cortex. Relaxation ratings did not correlate significantly with GM volume and none of the independent variables correlated with regional WM volume measures. Self-reported deeper levels of hypnosis were associated with less connectivity within the anterior default mode network. Taken together, the results suggest that the greater GM volume in the medial frontal cortex and ACC, and lower connectivity in the DMN during hypnosis facilitate experiences of greater hypnotic depth. The patterns of results suggest that hypnotic depth and hypnotic suggestibility should not be considered synonyms. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.
    No preview · Article · Dec 2014 · Psychiatry Research: Neuroimaging
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    • "Other research suggests that there are individual differences between high and low hypnotizable subjects in the tendency to employ imagery in suitable contexts (e.g., Tellegen and Atkinson, 1974; Hilgard, 1979; Wilson and Barber, 1982; Roche and McConkey, 1990; Lynn and Green, 2011). However, the tendency to employ imagery in certain contexts may reflect strategic differences rather than ability differences given that high susceptible participants are not especially quick at visual information processing (Acosta and Crawford, 1985; Friedman et al., 1987) and are not especially high in rated imagery vividness (Jamieson and Sheehan, 2002; though compare the feats of imagery achieved by high but not low susceptible subjects in Mazzoni et al., 2009). These suggestions are tentative given that we did not run low hypnotizable subjects. "
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    ABSTRACT: Grapheme-color synesthesia is a perceptual experience where graphemes, letters or words evoke a specific color, which are experienced either as spatially coincident with the grapheme inducer (projector sub-type) or elsewhere, perhaps without a definite spatial location (associator sub-type). Here, we address the question of whether synesthesia can be rapidly produced using a hypnotic color suggestion to examine the possibility of "hypnotic synesthesia", i.e., subjectively experienced color hallucinations similar to those experienced by projector synesthetes. We assess the efficacy of this intervention using an "embedded figures" test, in which participants are required to detect a shape (e.g., a square) composed of local graphemic elements. For grapheme-color synesthetes, better performance on the task has been linked to a higher proportion of graphemes perceived as colored. We found no performance benefits on this test when using a hypnotic suggestion, as compared to a no-suggestion control condition. The same result was found when participants were separated according to the degree to which they were susceptible to the suggestion (number of colored trials perceived). However, we found a relationship between accuracy and subjective reports of color in those participants who reported a large proportion of colored trials: trials in which the embedded figure was accurately recognized (relative to trials in which it was not) were associated with reports of more intense colors occupying a greater spatial extent. Collectively, this implies that hypnotic color was only perceived after shape detection rather than aiding in shape detection via color-based perceptual grouping. The results suggest that hypnotically induced colors are not directly comparable to synesthetic ones.
    Full-text · Article · Apr 2014 · Frontiers in Human Neuroscience
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    • "Testing the ability to experience color hallucinations without hypnosis. TS- H was then given instructions to use mental imagery as suggested by Mazzoni et al. (2009): Downloaded by [Hogskolebiblioteket I Skovde] at 07:38 19 August 2013 Previous research has shown that some people with very high levels of imaginative ability are able to see color stimuli as gray and gray as colored . Research has also shown that people can respond to suggestions for perceptual alterations whether or not they have been hypnotized. "
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    ABSTRACT: Abstract The authors studied whether a posthypnotic suggestion to see a brief, masked target as gray can change the color experience of a hypnotic virtuoso. The visibility of the target was manipulated by varying the delay between the target and the mask that followed it. The virtuoso's subjective reports indicated that her conscious color experience was altered already at short delays between the target and the subsequent mask. The virtuoso's objectively measured pattern of responding under posthypnotic suggestion could not be mimicked either by control participants nor the virtuoso herself. Due to posthypnotic amnesia, the virtuoso was unaware of suggestions given during hypnosis. Importantly, the virtuoso could not alter her color perception without a hypnotic suggestion. These results suggest that hypnosis can affect even a highly automatic process such as color perception.
    Full-text · Article · Oct 2013 · International Journal of Clinical and Experimental Hypnosis
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