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Ayahuasca and Default Mode Network

Harvard Dataverse (Africa Rice Center, Bioversity International, CCAFS, CIAT, IFPRI, IRRI and WorldFish)

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Title Ayahuasca and Default Mode Network
 
Identifier https://doi.org/10.7910/DVN/28619
 
Creator Palhano-Fontes, Fernanda
Andrade, Katia Cristine
Tofoli, Luis Fernando
Santos, Antonio Carlos
Crippa, Jose Alexandre
Hallak, Jaime
Ribeiro, Sidarta
de Araujo, Draulio
 
Publisher Harvard Dataverse
 
Description To investigate how Ayahuasca interferes with the Default Mode Network (DMN) activity a fluency verbal task was used. Subjects underwent two fMRI sessions, before and 40 min after Ayahuasca intake. To evaluate DMN activity, a verbal fluency task, designed as a block paradigm, was used. This task consisted in alternated six blocks of rest with five blocks of silently generated words starting with a cued letter (M, A, E, C and S, one letter for each block). Each block lasted 27.5 seconds. During rest periods the subjects were asked to think of a white wall. Experimental group maps were compared between conditions. For
each subject, a contrast was applied (rest > task) using a t-test. The contrasts then entered into a second level fixed effect analysis in order to perform a paired comparison of the two instants: before (DMN-Before) and after (DMN-After). Images from the resting state paradigm were used to evaluate seed-based functional connectivity (fc-fMRI). Two seeds were used: PCC (MNI coordinates: -4, -47, 45) and mPFC (MNI coordinates: 0, 51, -14). Ayahuasca caused a significant decrease in activity through most parts of the DMN, including its most consistent hubs: the Posterior Cingulate Cortex (PCC)/Precuneus and the medial Prefrontal Cortex (mPFC).Functional connectivity within the PCC/Precuneus decreased after Ayahuasca intake.
 
Subject Ayahuasca
DMN
fMRI
 
Date 2015