This research on the use of repetitive percussion instrument sequences during shamanic journeying was carried out by Bruno Gingras, ^* Gerald Pohler, and W. Tecumseh Fitch . The copyrighted published report on the research was edited by Sonja Kotz and published in the journal of the PUBLIC LIBRARY OF SCIENCE (PLOS) https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0102103 ; on July 7 2014 

The research includes shamanic journeying practice assisted by either drum or rattle.

Please click this LINK to download a text file copy of the research report