Multisensory Integration Is Modulated by Hypnotizability.

This study investigated multisensory integration in 29 medium-to-high (mid-highs) and 24 low-to-medium (mid-lows) hypnotizable individuals, classified according to the Stanford Hypnotic Susceptibility Scale, Form A. Participants completed a simultaneity judgment (SJ) task, where an auditory and a visual stimulus were presented in close proximity to their body in a range of 11 stimulus onset asynchronies. Results show that mid-highs were prone to judge audiovisual stimuli as simultaneous over a wider range of time intervals between sensory stimuli, as expressed by a broader temporal binding window, when the visual stimulus precedes the auditory one. No significant difference was observed for response times. Findings indicate a role of hypnotizability in multisensory integration likely due to the highs' cerebellar peculiarities and/or sensory modality preference.

Association of hypnotizability and deep sleep: any role for interoceptive sensibility?

The aim of the study was to investigate the possible association of hypnotizability and deep sleep (N3) duration, and whether the interoceptive sensibility influences this association. This was motivated by the proneness of highly hypnotizable individuals to easily change their psychophysiological state, i.e., from wakefulness to hypnosis and sleep, and by the positive association observed between hypnotizability and interoceptive sensibility. Forty-seven healthy participants previously enrolled in a polysomnographic night sleep study completed the questionnaire for Multidimensional Assessment of Interoceptive Awareness (MAIA) and underwent hypnotic assessment through the Stanford Hypnotic Susceptibility Scale, form A (SHSS,A). Results showed that N3 duration is not linearly correlated with hypnotizability. Controlling for a few MAIA scales did not modify the relation between hypnotizability and deep sleep. A polynomial relation indicates that N3 duration and N3 percentage of the total sleep time increase with hypnotizability in the low-to-medium range of hypnotizability and decrease in the medium-to-high range. In conclusion, hypnotic assessment predicts N3 duration and their association is not modified by interoceptive awareness/sensitivity.

Hypnotizability and the Peripersonal Space.

High hypnotizability is associated with left-sided cerebral asymmetry, which could influence measurement of the Peripersonal Space (PPS). Right-handed participants with high (highs, n = 20), medium (mediums, n = 9), and low hypnotizability scores (lows, n = 20) performed the line bisection test on a computer screen automatically displaced at distances of 30, 60, and 90 cm from the subjects' eyes. Highs' results showed rightward bias of the bisection (Relative Error, RE) for all presentation distances. In contrast, in lows RE was displaced leftward at 30 cm and exhibited a progressive rightward shift at 60 and 90 cm, as occurs in the general population. Mediums' RE values were intermediate between highs' and lows' values. Bisection Times (BT) were significantly longer in highs/mediums than in lows. Findings indicate that the highs' bisection identifies PPS as if it was extrapersonal, but further studies should assess its functional characteristics. The highs/mediums longer BT suggest less efficient sensorimotor performance.