Elsevier

Phytomedicine

Volume 5, Issue 2, April 1998, Pages 87-96
Phytomedicine

Effects of Ayahuasca on the human EEG

https://doi.org/10.1016/S0944-7113(98)80003-2Get rights and content

Summary

EEG data were recorded under field conditions from 11 members of the Santo Daime Doctrine, a Brazilian shamanistic religion, before and after ingesting the psychoactive alkaloid preparation, ayahuasca, or daime, as they term it. Post-ingestion, we observed increases in power in the 36–44 Hz frequency band (“40 Hz”) from the left occipital-temporal-parietal scalp electrodes in the eyes-closed condition, which extended to most of the posterior scalp in the eyes-open condition. The results are consistent with many reports that ayahuasca intensifies visual imagery. These results are discussed in terms of a thalamocortical model of the role of 40 Hz activity in brain function and conscious experience. We also noted tendencies toward decreases in the power of slow (theta and alpha) brain rhythms, and increases in the 14–30 Hz beta band, in accord with studies reported 30 years ago with other consciousness-altering compounds. Analysis of four ayahuasca samples yielded an average composition per ingested dose (75 ml) of 55.6 mg harmine, 43.9 mg tetrahydroharmine, 41.3 mg N,N-dimethyltryptamine (DMT), 4.6 mg harmaline, and 3.1 mg harmol. The DMT appeared to be of sufficient concentration to promote psychoactive effects, while the β-carbolines functioned to supply MAO inhibitors necessary to prevent degradation of DMT and to maintain its oral activity.

References (30)

  • J.C. Callaway et al.

    Platelet serotonin uptake sites increased in drinkers of ayahuasca

    Psychopbarmacol.

    (1994)
  • J.C. Callaway et al.

    Quantitation of N,N-dimethyltryptamine and harmala alkaloids in human plasma after oral dosing with ayabuasca

    J. Anal. Tox.

    (1996)
  • M. Fink

    EEG and psychopharmacology

    Contemp. Clin. Neuropbys. Suppl.

    (1978)
  • M. Fink

    Pharmaco-electroencephalography as a method to assess bioequivalence of central nervous system active substances in humans

    Integrative Psycb.

    (1985)
  • C.S. Grob et al.

    Human psychopharmacology of hoasca, a plant hallucinogen used in ritual context in Brazil

    J. Nervous and Mental Dis.

    (1996)
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    Address N. S. Don, Dept. of Psychiatry and School of Public Health, University of Illinois at Chicago, EOHS (M/C 922), 2121 W Taylor Street, Chicago, IL 60612

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