ECG
No significant difference was observed in the autonomic state between
groups and within conditions. Seemingly different findings with respect
to other studies can be accounted for by differences in the experimental
design. The absence of significant differences between groups in the
closed eyes awake condition (R) lasting 3 minutes accords with the
observation that significant differences between highs and lows appear
during longer-lasting relaxation (15 minutes) (Santarcangelo et al.,
2012). Moreover, a decrease in the absolute LF power and an increase in
the absolute HF power have been observed during a 20 minutes neutral
hypnosis, with consequent reduction of the LF/HF ratio (Santarcangelo et
al., 1992). Finally, in other studies (De Benedittis et al., 1994),
decreasing normalized LF and increased normalized HF have been observed
during the second 10 minutes of a 20 minutes neutral hypnosis including
imaginative suggestions promoting relaxation.