Employing measures of pain perception, autonomic and neuroormonal responses, this study is aimed at determining these pain-related modulations in healthy subjects in respect of hypnotizability.

Eighteen healthy subjects, aged 20–32 yrs, participated in the study. Subjects were subgrouped as highly (H), or low (L) susceptible to hypnosis, through a standard scale. Somatosensory and pain thresholds were extimated at 60% and 20% of a numerical scale, ranging between 0 (no sensation) and 100 (pain tolerance threshold). For each condition, 100 stimulation trials were performed, using constant current monophasic pulses of 2 ms, intracutaneously applied to the left-hand finger tip. ECG recordings were segmented into two 5-min periods, before and after stimulation. Variations in heart rate (HRV) were evaluated according to Niskanen et. al (2004). In addition, saliva samples were collected for alpha-amylase and cortisol assays.

No statistically significant differences were found for pain threshold between H and L. Changes were found in HRV time domain parameters between H and L and between test conditions. However, when the LF/HF ratio was considered or when LF and HF were analyzed in normalized units, no significant difference were present. Alpha-amylase levels significantly increased after both pain and somatosensory stimulations in H and L.

Overall, these results showed no evidence of an interaction between autonomic and neuroendocrine response and hypnotizability trait.