70787
document
Serotonergic psychedelics temporarily modify information transfer in humans . BACKGROUND Psychedelics induce intense modifications in the sensorium , the sense of " self , " and the experience of reality . Despite advances in our understanding of the molecular and cellular level mechanisms of these drugs , knowledge of their actions on global brain dynamics is still incomplete . Recent imaging studies have found changes in functional coupling between frontal and parietal brain structures , suggesting a modification in information flow between brain regions during acute effects . METHODS Here we assessed the psychedelic-induced changes in directionality of information flow during the acute effects of a psychedelic in humans . We measured modifications in connectivity of brain oscillations using transfer entropy , a nonlinear measure of directed functional connectivity based on information theory . Ten healthy male volunteers with prior experience with psychedelics participated in 2 experimental sessions . They received a placebo or a dose of ayahuasca , a psychedelic preparation containing the serotonergic 5-HT2A agonist N , N-dimethyltryptamine . RESULTS The analysis showed significant changes in the coupling of brain oscillations between anterior and posterior recording sites . Transfer entropy analysis showed that frontal sources decreased their influence over central , parietal , and occipital sites . Conversely , sources in posterior locations increased their influence over signals measured at anterior locations . Exploratory correlations found that anterior-to-posterior transfer entropy decreases were correlated with the intensity of subjective effects , while the imbalance between anterior-to-posterior and posterior-to-anterior transfer entropy correlated with the degree of incapacitation experienced . CONCLUSIONS These results suggest that psychedelics induce a temporary disruption of neural hierarchies by reducing top-down control and increasing bottom-up information transfer in the human brain .
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Intervention_Pharmacological
Serotonergic psychedelics
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Intervention_Pharmacological
Psychedelics
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Intervention_Pharmacological
psychedelics
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Intervention_Control
placebo
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Intervention_Pharmacological
dose of ayahuasca
70793
Intervention_Pharmacological
psychedelic
70794
Intervention_Pharmacological
serotonergic 5-HT2A agonist N , N-dimethyltryptamine
70795
Intervention_Pharmacological
psychedelics
70796
Outcome_Mental
global brain dynamics
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Outcome_Other
changes in directionality of information flow
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Outcome_Mental
brain oscillations
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Outcome_Physical
changes in the coupling of brain oscillations
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Outcome_Physical
anterior-to-posterior transfer entropy
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Outcome_Physical
anterior-to-posterior
70802
Outcome_Physical
posterior-to-anterior transfer entropy
70803
Outcome_Physical
temporary disruption
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Outcome_Mental
neural hierarchies
70805
Participant_Sample-size
Ten
70806
Participant_Sex
male
70807
Participant_Condition
prior experience with psychedelics