Among the many contributions the late Bob Wallace made to psychedelic drug education and research is the 21-channel EEG he helped MAPS buy for my research in September. Through his Promind Foundation, Bob supported my work as MAPS Forum Editor with a $350/month grant beginning in January 2001. After I graduated in August 2001, I decided that I no longer needed the money for a personal stipend, and asked MAPS to start saving it for my future research. We chose the Mitsar EEG because of its low cost, portability, and the impressive "WinEEG" software package designed by Drs. Juri Kropotov and Valery Ponomarev of the Russian Academy of Sciences in St. Petersburg. This software provides for analysis of EEG spectral magnitude, coherence, and event-related potentials, synchronization/desynchronization, and wavelet transforms. The software also includes a module for designing custom biofeedback sessions (see http://www.maps.org/eeg/braintune-eeg.htm for specs).

I decided to get this equipment so that EEG recording will be available for all MAPS-sponsored studies, or for any IRB-approved human psychedelic study. While I am personally pursuing several leads for "piggybacking" EEG recordings on top of other studies, we are also accepting proposals for original research to utilize this equipment. I am personally motivated to do the data analysis and provide technical support for those who are interested in doing the recordings. I would also be delighted to hear from any psychiatrists in Houston/Austin/Dallas who would like to join me in seeking IRB approval for a study here at the University of Texas.

My personal interest in studying the EEG of psychedelic drug states evolved from my interest in biofeedback. By providing a representation of physiological activity in real time, biofeedback therapy can train you to increase conscious awareness and voluntary control over processes that are ordinarily subconscious and involuntary (Olson, 1987). Since psychedelics are known to "expand consciousness" or to lower the inhibitions to experiencing aspects of the subconscious, I have hypothesized that psychedelics could potentially enhance the rate or extent of learning a biofeedback task.

If one could identify factors in the EEG that correlate specifically with the desired effects of psychedelics, these factors could then provide the basis (criteria for reinforcement in operant conditioning) for an EEG biofeedback therapy to produce those effects without drugs or at lower dosages. This could contribute to (a) a lessening of some of the legal hazards associated with the pursuit of altered states via psychedelics, and (b) a potential to improve the integration of insights from the transcendental psychedelic state with ordinary consciousness--both personally by patients, and theoretically by scientists. A lot of research has been done on the EEG effects of transcendental meditation. Since there are some long-standing controversies about whether psychedelics can provide any of the benefits of meditation, it would be of interest to both sides to study the similarities and differences between the EEG effects of psychedelics and of meditation.

Before doing such applied studies, however, I would first like to get a better idea of what psychedelics are doing to the EEG. Early studies found that LSD, psilocybin, and mescaline tended to decrease theta (4-8 Hz) and alpha (8-12 Hz) activity, while increasing beta (12-30 Hz) activity (Wikler, 1954; Itil, 1968). However, Hoffmann, Hesselink and Silveira Barbosa (2001) observed that the peak effects of ayahuasca (DMT) increased theta and alpha amplitudes while beta remained unchanged. A more recent study found that ayahuasca dose-dependently decreased activity in all bands from 1.3-30 Hz. (Riba, Anderer, Morte, Urbano, Jane, Saletu, & Barbanoj, 2002). Krupitsky and Grinenko (1997) found that ketamine decreased alpha and increased delta and theta activity. Lukas, Mendelson, Amass and Benedikt (1989) described increases in alpha with acute administration of cannabis, but also with morphine, amphetamine, pentobarbital, nicotine, and ethanol.

The inconsistency of results across psychedelic substances suggests to me that finding specific correlates of psychedelic experiences will require more powerful analytic methods. The variable analyzed in nearly all psychedelic EEG studies has been EEG power or amplitude, essentially the "loudness" of the EEG in various frequencies across the scalp. However, a correlational measure of EEG called coherence has been found to be more sensitive and specific than EEG power, and remains vastly unexplored in psychedelic studies. The coherence between two electrodes suggests the extent to which the underlying brain regions are cooperating on the same task. Since the purpose of the nervous system, arguably, is to make connections among aspects of the internal and external world, such a correlational measure of the EEG might also be a more valid measure for psychophysiology in addition to a more reliable one.

Other more valid EEG measures have come from the nonlinear dynamic systems (or "chaos theory") approach to signal analysis. The standard approach in quantitative EEG is to take the average across the time series, and make comparisons between averages. The variation over time, in this paradigm, is considered a source of noise that can be eliminated by taking a sufficiently large number of samples. However, the mind and brain are dynamic systems, for which time is an essential property, not just a source of error in our measurements. The first step in a nonlinear dynamic approach is to characterize the "phase space," or the important variables governing the system, and the path the system travels through those variables over time. The number of relevant variables needed to explain the system is called dimensional complexity. It would be very interesting to see whether psychedelics decrease the dimensional complexity of the EEG (reflecting, perhaps, the feelings of cosmic "unity"), or increase its complexity (corresponding to the perceptions of parallel universes or "multiple realities"). Perhaps psychedelic phase spaces might be characterized by fluctuations between high and low dimensional states. Mapping the phase space could help to identify critical periods in the trajectory of the system when small interventions can have dramatic effects. Methods for doing nonlinear analysis of the EEG are in early stages of development, however, so this is an active area of study for me.

Currently, I am doing recordings and analysis under relatively boring conditions (eyes-closed, eyes-open, photic stimulation), to become familiar with the software, and to do reliability and validity studies for the methods I plan to employ in my research for MAPS.

References

Hoffmann, E., Hesselink, J.M.K., & da Silveira Barbosa, Y.-W.M. (2001). Effects of a psychedelic, tropical tea, ayahuasca, on the electroencephalographic (EEG) activity of the human brain during a shamanistic ritual. MAPS Bulletin 11(1):25-30.

Itil, T.M. (1968). Electroencephalography and pharmacopsychiatry. Clin. Psychopharmacol. 1:163-194.

Krupitsky, E.M. & Grinenko, A.Y. (1997). Ketamine psychedelic therapy (KPT): A review of the results of ten years of research. J. Psychoactive Drugs 29(2):165-183.

Lukas, S.E., Mendelson, J.H., Amass, L., Benedikt, R. (1987). Behavioral and EEG studies of acute cocaine administration: Comparisons with morphine, amphetamine, pentobarbital, nicotine, ethanol and marijuana. NIDA Res. Monograph Series 95:146-151.

Olson, R.P. (1987). Definitions of biofeedback. In M.S. Schwartz and Associates (Eds.), Biofeedback: A practitioner's guide (Chap. 3). New York: Guilford Press.

Riba, J., Anderer, P., Morte, A., Urbano, G., Jane, F., Saletu, B., & Barbanoj, M.J. (2002). Topographic pharmaco-EEG mapping of the effects of the South American psychoactive beverage ayahuasca in healthy volunteers. Br. J. Clin. Pharmacol. 53(6):613-28.

Wikler, A. (1954). Clinical and electroencephalographic studies on the effects of mescaline, N-allylnormorphine and morphine in man. J. Nervous and Mental Dis. 120:157-175.