Subjects
A priori power analysis performed by G*Power3.1 (Faul et al., 2009) for repeated measures ANOVA indicated that for the expected η2 = 0.3 (Pollatos et al., 2005) and α = .05 the sample size of 16 participants for each group would be enough to achieve power = 0.89. After the approval by the Bioethics Committee of the University of Pisa (n.17/2021), participants of both sexes were recruited among the right-handed (Edinburgh Handedness Inventory, score> 16) students at the University of Pisa who had undergone hypnotic assessment through the Italian version of the Stanford Hypnotic Susceptibility Scale, form A (SHSS, A (range: 0-12), Weitzenhoffer & Hilgard, 1959,) in the latest 6 months. Details regarding hypnotizability SHSS scales are available in Sheehan and McConkey (1981). After their written informed consent, 16 highs (SHSS score (mean + sd): 10.18 + 1.19; 9 females, age: 25.14+ 3.82 yrs) and 16 lows (SHSS score: 0.20 + .56; 7 females, age: 26.47 + 4.82 yrs) with medical, neurological and psychiatric negative anamnesis, no attention /sleep disturbance and drugs intake in the latest 6 months were enrolled. The final group was composed of 16 highs and 15 lows because one of the male lows was excluded from analyses owing to technical problems in the ECG recording. The two groups were homogeneous for education (master’s students). Six highs and 3 lows reported basic experience of meditation. Medium hypnotizable individuals (mediums) were not enrolled to maximize the effects of hypnotizability on the studied variables during hypnosis (De Pascalis et al., 2000; Elkins et al., 2015).