The relation of susceptibility levels of hypnosis and different mental tasks

The analysis of electroencephalogram (EEG) signals plays an important role in a various applications. EEG during pure hypnosis has different characteristics compared to normal non-hypnotic EEG especially in the frontal area of the brain. The purpose of this paper is to examine whether there is any similarity between different levels of hypnosis susceptibility and mental tasks using Fuzzy Similarity Index (FSI) method. In the first step, some of nonlinear features of EEG signals extracted; the next part of this method is to calculate the similarity between the features set of the reference segment (mental tasks) and the test segment (hypnosis signal) using fuzzy measure. Our results demonstrate that FSI is suitable for discriminating the relations between different status of brain activity in the non-hypnotic and hypnosis EEG signals. The more complex mental task, the behavior of the brain is more like a hypnotic state. Our results confirm previous ones that more activity of the right hemisphere during hypnosis was reported in right-hand subjects.