Intact neurophysiological markers of death denial in ayahuasca veterans

Ayahuasca veterans' brains show automatic, unconscious denial of death when processing self-related death stimuli, measured via magnetoencephalogram (MEG), while their conscious self-reports indicate less fear of death than the general population and experienced meditators. The neurophysiological marker of death denial correlated with lower self-reported death acceptance, reduced accessibility to death-related thoughts, and greater life satisfaction, suggesting an adaptive role. Despite psychedelic-induced changes in conscious attitudes toward mortality, unconscious cognitive processes underlying mortality avoidance remain intact, limiting the transformative efficacy of psychedelics on deep-seated death denial.

Study at a glance

Abstract

There is a growing hype regarding the efficacy of psychedelics to fundamentally change how we interact with the theme of death. The underlying evidence consists of anecdotal and self-report data collected in naturalistic and clinical settings suggesting that psychedelics inculcate more acceptance and less fear and anxiety of one’s mortality. However, given hundreds of empirical studies implicating unconscious cognitive processes in mortality avoidance, the current state of the literature is limited and calls for a more robust stratification of the phenomena by collecting implicit behavioral and no-report neurobiologically-informed evidence. Thus, here we implement a previously validated no-report magnetoencephalogram (MEG) visual MisMatch Response (vMMR) paradigm for assessing whether ayahuasca veterans’ brains, relative to previously published data of healthy controls and experienced meditators, display neurophysiological markers of denial or acceptance of death, respectively. Self-report and behavioral measures of fear-of-death were also collected. The results show that ayahuasca veterans’ brains responded to the coupling of death and self-stimuli in a manner indicating denial rather than acceptance. At the same time, the ayahuasca sample displayed less fearful behavioral responses than the general population, and less self-reported fear-of-death than both the general and the meditators sample. Further analyses on the neurophysiological marker of death denial support its construct validity by associating it with less self-reported death acceptance and reduced accessibility to death-related thoughts. Finally, death denial was also associated with greater life satisfaction, supporting the adaptive role of the neural machinery underlying mortality defenses. Overall, our findings provide preliminary evidence that while ayahuasca may alter how humans interact with the theme of death on conscious levels of cognitive processing, on automatic unconscious levels of perceptual self-specific processing, death denial processes appear to remain intact. The limits of psychedelics transformative efficacy are discussed considering current frameworks of psychedelic action and attentional training.