Looking for the Self: Phenomenology, Neurophysiology and Philosophical Significance of Drug-induced Ego Dissolution

Abstract

There is converging evidence that high doses of hallucinogenic drugs can produce significant alterations of self-experience, described as the dissolution of the sense of self and the loss of boundaries between self and world. This article discusses the relevance of this phenomenon, known as “drug-induced ego dissolution (DIED)”, for cognitive neuroscience, psychology and philosophy of mind. Data from self-report questionnaires suggest that three neuropharmacological classes of drugs can induce ego dissolution: classical psychedelics, dissociative anesthetics and agonists of the kappa opioid receptor (KOR). While these substances act on different neurotransmitter receptors, they all produce strong subjective effects that can be compared to the symptoms of acute psychosis, including ego dissolution. It has been suggested that neuroimaging of DIED can indirectly shed light on the neural correlates of the self. While this line of inquiry is promising, its results must be interpreted with caution. First, neural correlates of ego dissolution might reveal the necessary neurophysiological conditions for the maintenance of the sense of self, but it is more doubtful that this method can reveal its minimally sufficient conditions. Second, it is necessary to define the relevant notion of self at play in the phenomenon of DIED. This article suggests that DIED consists in the disruption of subpersonal processes underlying the “minimal” or “embodied” self, i.e., the basic experience of being a self rooted in multimodal integration of self-related stimuli. This hypothesis is consistent with Bayesian models of phenomenal selfhood, according to which the subjective structure of conscious experience ultimately results from the optimization of predictions in perception and action. Finally, it is argued that DIED is also of particular interest for philosophy of mind. On the one hand, it challenges theories according to which consciousness always involves self-awareness. On the other hand, it suggests that ordinary conscious experience might involve a minimal kind of self-awareness rooted in multisensory processing, which is what appears to fade away during DIED.

DMT Models the Near-Death Experience

“…Remarkably, the overlap between the phenomenology of the classic serotonergic psychedelic experience and NDEs was highlighted by Moody himself more than 4 decades ago (Moody, 1975) and these similarities have formed the basis of a popular hypothesis on the pharmacology of NDEs, i.e., that endogenous DMT is released in significant concentrations during the dying process (Strassman, 2001), but see (Nichols, 2017) for a critique of this hypothesis. The psychological state produced by the DMT-containing Amazonian brew, ayahuasca (the literal translation of ‘ayahuasca’ from quechua is ‘the vine of the dead’ or ‘the vine of the soul’), has also been linked to themes of death and dying (Shanon, 2005) as have psychedelics in general (Millière, 2017), e.g., with the psychology of psychedelic-induced ‘ego-death’ being likened to that of actual death (Leary et al, 2008). …”

Dissolving the self

“…One of the most striking and philosophically interesting effects of psychedelics is the radical disruptions of self-consciousness they can occasion (Huxley, 2010;Leary, Metzner, & Alpert, 1964), including apparently "selfless states" (Lebedev et al, 2015;Nour, Evans, Nutt, & Carhart-Harris, 2016). These states, instances of "Drug-Induced Ego-Dissolution" (DIED) are characterised by an experienced loss of self and/or loss of self/world boundary (Millière, 2017;Millière, Carhart-Harris, Roseman, Trautwein, & Berkovich-Ohana, 2018). DIED occurs most reliably under high doses of "classical" psychedelic drugs (5-HT 2A receptor agonists), such as dimethyltryptamine (DMT), lysergic acid diethylamide (LSD), and psilocybin.…”

“…The fact that the highest level of the self-model are "increasingly abstract, complex and invariant" (Limanowski & Friston, 2018, p. 5), may explain why higher levels of the self-model are going to be less perturbed by prediction error and perhaps only reliably altered at high dosages. Empirical exploration of these possibilities might be a fruitful avenue for future work, in particular through bridging the neurocomputational mechanisms posited here to both the dynamics of the experience as uncovered through "microphenomenological" interviews (Millière, 2017;Petitmengin, 2006), and to the underlying neural correlates of the experience (Timmermann et al, 2019).…”

“…Although the experience is notoriously difficult to articulate and even considered ineffable, psychedelic researcher Stanislas Grof, who considers egodissolution the "main objective" of psychedelic therapy, describes it as "an ecstatic state, characterized by the loss of boundaries between the subject and the objective world, with ensuing feelings of unity with other people, nature, the entire Universe, and God" (Grof, 1980, p. 79). 1 Ego-dissolution is of considerable philosophical and theoretical value for understanding selfhood and the nature of consciousness (Letheby & Gerrans, 2017;Millière, 2017;Nour & Carhart-Harris, 2017). 2 It is also considered to be central to the therapeutic potential of psychedelics (Carhart-Harris & Goodwin, 2017; see also Letheby, 2020, Limanowski & Friston, 2020, Sebastián, 2020, all in this special issue).…”

5-methoxy-N,N-dimethyltryptamine: An ego-dissolving endogenous neurochemical catalyst of creativity

“…In the context at hand, one of their most important qualities is their ability to catalyze novel cognitions and perceptions and their potential to induce the process of ego-dissolution, viz., a state of non-dual consciousness 14 (Carhart-Harris, Erritzoe, Haijen, Kaelen, & Watts, 2018;J. V. Davis, 2011;Millière, 2017;Nour et al, 2016a). In this state of nondual consciousness habitual categorical dichotomies which normally structure the all experiences are dissolved.…”