• EEG
• Hypnotizability
• imagery

The aim of study was to investigate whether subjects with high (highs) and low (lows) scores of hypnotizability differ in the cortical representation of visual and kinaesthetic mental images of rotated head posture and in the relation between these representations and that associated with the perception of physically rotated head posture.
Subjective reports of the vividness of visual imagery and relative cognitive effort and the power of EEG spectral frequencies (alpha, theta, beta gamma) were studied in 21 highs and 20 lows recruited among 200 participants who accepted to have their hypnotizability assessed through the Italian version of the Stanford Hypnotic Susceptibility Scale, form A.
The findings of the present study show that a) highs report higher vividness of mental images than lows and the same effort; b) in general highs and lows show scarce differences in the representation of the two imagery modalities; the highs’ beta3 power was modulated during kinaesthetic imagery and the lows’ beta3 was influenced by the visual imagery; c) hypnotizability and gender interact in the modulation of alpha1 (medioposterior, occipital), alpha2 (occipital), theta 2 (occipital) and gamma (occipital) independently of the specific tasks.
In conclusion, although findings should be considered preliminary, they are in line with the hypothesis that imagery and perception may have hypnotizability-related cortical representation, but do not provide sufficient evidence for a different degree of their superimposition to the representation of the physically rotated head in highs and lows. Investigation of EEG dynamics is likely to better capture similarities and differences and is in progress.