Fig. 1

Comparison of power spectra between periods of deep hypnosis and wakefulness

This is an example of topographic maps displaying the differences in the averaged power spectra between deep hypnosis and the waking periods of EEG (“deep hypnosis” minus “wakefulness”) for three patients. Sessions for display are arbitrarily selected. Thus, the maps demonstrate the alterations in the power of different rhythms for different localizations while achieving deep hypnosis. Power changes are displayed in colour according to the graduation of a nearby colour scale (in uV²). The bands used are: Delta (1.5-4 Hz), Theta (4–8 Hz), Alpha (8–12 Hz), Sensory-motor or Low beta (12–15 Hz), Beta1 (15–18 Hz), Beta2 (18–25 Hz) and Gamma (25–45 Hz)