Binaural beat induced Theta EEG activity and hypnotic susceptibility: Contradictory results and technical considerations

American Journal of Clinical Hypnosis,  Apr 2003  by Stevens, Larry,  Haga, Zach,  Queen, Brandy,  Brady, Brian,  Et al

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An additional prediction of this study was that there would be a significant positive relationship between frontal theta power and hypnotizability, such that those participants who produced higher frontal theta power were expected to be higher in hypnotizability at baseline. This relationship was tested by separate one-way ANOVA's. As this was an investigational study, alpha levels for statistical significance were set at .10 in all analyses.

Results

Analysis of Theta Changes

Analysis of frontal theta EEG's indicated a within-subjects main effect for changes in theta power across training (F(4, 21) = 9.285, p

Author Note

This study was conducted as part of a National Science Foundation Research Experience for Undergraduates conducted by Zach Haga and Brandy Queen under the direction of Larry Stevens. Parts of this study were presented by Zach Haga as a part of a symposium on The Neurological Bases of Hypnosis at the 43rd Annual Scientific Meeting and Workshops on Clinical Hypnosis of the American Society of Clinical Hypnosis held in Reno, Nevada, March 23-27, 2001.

The authors would like to express their appreciation to the Scientific Editor and to two anonymous reviewers for their very helpful suggestions on an earlier version of this manuscript.

1Gorassini, Sowerby, Creighton, and Fry (1991) have condensed this 1-hour cognitive skills training program into a 10-minute educational manipulation and have shown significant increases in susceptibility in one study using this brief intervention. However, this 10-minute training program has not been supported on replication (Milling, Kirsch, & Burgess, 1999).

2Two participants scoring 8 on the SHSS:C were included in the data analysis because of moderate scores on both the Psychological Absorption Scale and the Creative Imagination Scale, as well as an empirical justification for including such scorers in a "high medium" category (Perry, Nadon, & Button, 1992).

3A single monopolar site was used in this study because of data recording limitations of the NRS-2D Biolex software. Although the NRS-2D records and reports EEG data averages across a session for two channels, epoch-by-epoch data are only available for analysis on one channel. As F3 and F4 sites have been reported in research to be sensitive to theta frequency changes, a single site between F3 and F4, FZ, was identified for the present study.

4As we anticipated a rather dramatic effect of the TBB training on frontal theta EEG production and a stable non-effect of the control condition, a small control group not receiving theta training was run as a normative base for comparison of EEG change

References

Akpinar, S., Ulett, G.A., & Itil, T.M. (1971). Hypnotizability predicted by computer analyzed EEG pattern. Biological Psychiatry, 3, 387-392.

Andersen, P. & Andersen, S.A. (1968). Physiological basis of the alpha rhythm. New York: Appleton-Century-Crofts.

Atwater, F.H. (1995). The Monroe Institute's Hemi-Sync Process [On-Line serial]. Available at: http://www.monroeinstitute.org/research/hemi-sync-atwater.html. Atwater, F.H. (1996). Binaural beats and the frequency-following response: A pilot study. Unpublished manuscript.