Chaotic features analysis of EEG signals during standard tasks of Waterloo-Stanford

The present study looks carefully at EEG(Electroencephalograph) signals of people after the hypnosis inductions. Subjects were in three different categories of hypnotizability based on Waterloo-Stanford criteria; low, medium and high. Signals recorded during standard tasks of Waterloo-Stanford were applied to study the underlying dynamics of tasks and investigate the influence of hypnosis depth and concentration on recorded signals. To fulfill this objective, chaotic methods were employed; Higuchi dimension and correlation dimension. The results of the study indicate channels whose chaotic features are significantly different among people with various levels of hypnotizability and a great consistency exists among channels involved in each task with brain lobes´ functions.