Electrophysiological Alterations During Hypnosis for Ego-Enhancement: A Preliminary Investigation

American Journal of Clinical Hypnosis, Apr 2004 by Stevens, Larry, Brady, Brian, Goon, Angela, Adams, Deanna, Et al

EEG Recording

Continuous EEG (band pass: 0.5-32 Hz, 128 Hz sampling rate) was recorded at two electrode sites (Fz, Oz), referenced to linked ears with common/ground at Fpz 2. Resistance of electrodes was held below 10K ohms. Recording and processing of EEG data were performed with an NRS-2D (Lexicor Medical Technology, Inc., Boulder, Colorado) workstation. Data were submitted to automatic muscle and eye movement artifact rejection (� 40 uV) and were then visually scanned and artifacted by the PI. Using Lexicor's Fast-Fourier spectral analysis program, EEG power was evaluated for the following frequency bands: Delta (0-4 Hz), Theta (4-8 Hz), Alpha (8-12 Hz), and Beta (13-32 Hz).

Procedure

Participants were recruited and screened as described above. During Phase II, the SHSS:C was administered in a private therapy suite in the Department's Health Psychology Center by the PI and by two Psychology Department graduate students and one upper-division undergraduate student trained and supervised by the PI. Participants were then individually scheduled for the Phase III EEG study. At each phase of the study, experimenters and participants were blind as to participant's hypnotizability level.

The EEG study was conducted in a dimly lit, private therapy suite in the Health Psychology Center. The participant was seated upright with legs supported in a comfortable recliner. Electrode sites were prepped with abrasive gel and electrodes were attached according to the International 10-20 System. The participant was asked to relax while recording equipment was configured and valid and stable EEG traces were identified. This electrode attachment and equipment configuration procedure took 515 minutes. Each participant was then trained in the Spiegel Eye Roll Induction technique (Spiegel & Spiegel, 1978)1

The hypnotic induction process followed 7 stages as follows: 1) 5 minutes eyes closed prehypnosis baseline; 2) Spiegel Eye Roll Induction (-1.5 minutes); 3) Arm Eevitation Deepening (-14 minutes); 4) Passive Progressive Neuromuscular Relaxation (PNR) Deepening (-4 minutes); 5) Hammond's The Serenity Place (Hammond, 1990) permissive therapeutic suggestions for indirect ego-strengthening and increased coping abilities (-9 minutes); 6) Hypnosis Termination via reverse 5 count (~ 1.5 minutes); 7) 5 minutes eyes closed posthypnosis baseline. (See Appendix for hypnosis scripts.) The hypnosis induction, deepening, and therapeutic suggestions process was designed to replicate a commonly used hypnotic training procedure offered in workshops by the American Society of Clinical Hypnosis. This hypnosis process was administered live by two ASCH-trained clinicians with the hypnotist sitting in the therapy suite in a comfortable chair approximately 5 feet from the participant. Although the five hypnosis components were scripted, the trancework process was designed to flow naturally and spontaneously, as closely as possible replicating the hypnosis process that would occur in the clinician's office. EEGs were unobtrusively recorded continuously throughout this approximately 40-minute baseline and hypnosis process, with the hypnotist noting on a recording form the beginning epoch for each of the 7 stages. Following completion of this process, the participant was disconnected from the recording equipment, shown a tracing of their EEG during hypnosis, asked about their experiences during the process, and debriefed.