Hypnotized subjects who report hallucinating a visual situation which would ordinarily elicit optokinetic nystagmus demonstrate nystagmus under these conditions. They and control subjects are unable to feign nystagmus in the waking state, either by imagining the situation or by direct efforts to simulate the eye movements. Thus an objective criterion is provided for the presence of visual hallucinations.
Postural control in subjects with high (Highs) and low (Lows) susceptibility to hypnosis is differentially affected by changes in visual and neck tactile/proprioceptive input. The aim of the present experiment was to investigate whether imagery of the visual and tactile sensory modalities also induces different modulation of postural control in Highs and Lows. Fourteen Highs and 16 Lows were included in the study; they were recorded while standing upright with eyes closed during visual and tactile imagery tasks and during mental computation.
Five experiments tested the idea that instructing a witness to close their eyes during retrieval might increase retrieval success. In Experiment 1 participants watched a video, before a cued-recall test for which they were either instructed to close their eyes, or received no-instructions. Eye-closure led to an increase in correct cued-recall, with no increase in incorrect responses.