Suggested visual hallucinations in and out of hypnosis

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.     

Visual object imagery and autobiographical memory: Object Imagers are better at remembering their personal past

In the present study we examined whether higher levels of object imagery, a stable characteristic that reflects the ability and preference in generating pictorial mental images of objects, facilitate involuntary and voluntary retrieval of autobiographical memories (ABMs). Individuals with high (High-OI) and low (Low-OI) levels of object imagery were asked to perform an involuntary and a voluntary ABM task in the laboratory. Results showed that High-OI participants generated more involuntary and voluntary ABMs than Low-OI, with faster retrieval times. High-OI also reported more detailed memories compared to Low-OI and retrieved memories as visual images. Theoretical implications of these findings for research on voluntary and involuntary ABMs are discussed.     

Shaping our personal past: Assessing the phenomenology of autobiographical memory and its association with object and spatial imagery

A new instrument has been developed that allows a comprehensive assessment of the relevant dimensions of the phenomenology of autobiographical memories (Assessment of the Phenomenology of Autobiographical Memory, APAM), and their association with visual object and spatial imagery has been examined. An initial version of APAM consisting of 30 items (the first 28 measured on a seven-point Likert-type scale) was developed and administered to a sample of 138 undergraduates. To test whether each item consistently measured the same dimension across different memories, all questions were rated for 12 cues. Results showed that 25 Likert-type items possessed adequate levels of internal consistency and unidimensionality across cues. We also found that higher levels of visual object imagery were associated with more sensory details and recollective qualities of memory, and with stronger experience of sensory and emotional reliving. The theoretical and practical usefulness of APAM as well as the relevance of visual object imagery in the phenomenology of autobiographical memory are discussed.