Hypnotically induced emotional states alter the location of frequency domain EEG dipole source models.

T. Koenig, K. Kochi, I. Kondakor, D. Lehmann and D. Revenstorf

The KEY Institute for Brain-Mind Research, University Hospital of Psychiatry of Zurich, Switzerland and Psychological Institute of the University of Tuebingen, Germany.

This study relates spatial characteristics of frequency-transformed multichannel EEG to hypnotically induced positive and negative emotional states. While 12 healthy young volunteers were put into hypnotic trance and conducted through scenes of joy, fear, anger and sadness, their brain-electric field was continuously recorded from 27 derivations. For each emotional state, artefact-free data epochs were transformed into the frequency domain and reduced to single source dipole models in seven standard frequency bands. Comparing the location of the dipole models, we found the joy condition to be more left-lateralized and superior compared to the remaining negative emotions; this effect was most pronounced in a band from 18.5 to 21.0 Hz. Furthermore, a decrease of slow wave activity was observed during joy. We conclude that hypnotical induction of different emotional states activates at least partially different neural elements in a manner consistent over subjects. The observed lateralization is in agreement with another study on event-related potentials evoked by emotionally biased faces.