Losing the Self in Near-Death Experiences: The Experience of Ego-Dissolution

This verbatim extract, drawn from our collection of testimonies of near-death experiences (NDEs), includes mention of a dissolved sense of self, evoking comparisons with loss of self induced via other means such as meditation, sleep, or psychedelic drugs (e.g., [1,2,3]). NDEs are episodes of disconnected consciousness in which the person experiences various prototypical mental events, with highly emotional and mystical aspects [4]. NDEs typically occur in truly life-threatening situations such as cardiac arrest, traumatic injury, intracerebral hemorrhage, nearly drowning, or asphyxia [5]. NDEs can also occur in situations that feel life-threatening (e.g., high anxiety) and perhaps in situations such as meditation or sleep, which are then referred as “NDE-like” since the phenomenology is similar to a classical NDE yet without an actual imminent risk of death [6]. Currently, in research, the identification of NDE(-like) experiencers is based on the richness of the experience—that is, the presence and intensity of a number of defining features. The Near-Death Experience Content (NDE-C) scale has been very recently developed and validated to accurately identify these features and facilitate empirical research [7].

Among the defining features of NDEs, out-of-body experience (OBE) is the second most frequently reported feature, after a feeling of profound peacefulness [6,8,9,10]. OBEs are related to a compromised sense of possessing a single, integrated, and distinct identity, typically involving a shift in the subjectively experienced location of the perceived self and a disturbance of the sense of self (see [11] for a review). The construct of “the self” or “ego” is highly abstract and thus eludes a singular concrete definition (although, see these attempts: [12,13]), but it is often thought of as a subjective perception of oneself as a distinct entity [14] combined with a sense of a ‘narrative self’ or identity [15,16]. A disturbance of the sense of self may take various forms, ranging from a small disturbance of self-perception to completely losing the sense of ego.

In 2000, Greyson [17] found that NDE experiencers easily or frequently experience common and non-pathological dissociation states before and/or after having had their NDE, such as feeling as if their body does not belong to them. Such dissociative symptoms inherently include a disturbance of the sense of self by the partial or complete loss of the normal coordination between self, body, and environment [18]. However, so far, no empirical study has rigorously investigated the sense of self during the NDE itself, even though most experiencers seem to subsequently report a disruption of their sense of self when describing their experience.

The disturbance of the sense of self, in the form of an OBE or in any other form, may arise in many other types of contexts than during classical NDEs: it can occur spontaneously or in a specific pathological (e.g., acute psychosis; [19]) or non-pathological condition (e.g., meditation, sleep or drug-induced psychedelic experiences; [1,2,3]). Notably, evidence from studies involving psychedelic drugs has repeatedly shown that the experience of ego dissolution (i.e., a disruption of ego-boundaries which leads to a partial or complete blurring of the distinction between the self and the rest of the environment and other objects or people combined with a loss of self-identity or ‘narrative self’) is a very common feature of drug-induced experiences, especially following the ingestion of high doses [12,20]. This is especially true for classic psychedelic drugs (i.e., 5-HT2A receptor agonists) such as psilocybin [21,22] and N, N-Dimethyltryptamine (DMT) [23], as well as dissociative anesthetics such as ketamine [24], and the terpene salvinorin–A [25]. Specifically, many psychedelic drug ‘experience reports’ reference a sense of continuity or unity between their self and the external world [3], evoking the notion of disturbed ‘ego-boundaries’ [26] and the ‘unitive experience’ (defined by [27] as a sense of all-encompassing ‘unity’ or ‘oneness’). Importantly, the intensity of ego dissolution experienced under psychedelics correlates with the subsequently reported feeling of connectedness with nature and humanity [13,28,29]. Recently, Nour and colleagues [3] developed the Ego-Dissolution Inventory (EDI), a standardized scale designed to capture the experience of ego dissolution and associated feeling of unity with one’s surroundings. Its development was based on the ratings of 691 participants linked to their subjective experiences under classical psychedelics. The final scale includes eight items related to ego dissolution. In parallel, to aid the validation process, the authors also developed eight other items to assess the experience of ‘ego inflation’, which corresponds to an “unusually elevated self-assuredness and confidence” [3]. In short, they demonstrated that the experience of ego dissolution positively correlated with the dose and intensity of effects of a psychedelic drug, whereas the reported dosage of a control drug, cocaine, correlated with ego-inflation scores. Validation of the EDI and Ego-Inflation Inventory (EII) suggested a distinct factor structure separating the two measures but it was not clear if they were inversely related as one might assume. Interestingly, recent studies have shown that NDE-like episodes can be induced by the classic serotonergic psychedelic DMT [23] or ketamine [30].

So far, no study has explored the sense of ego dissolution and inflation in a large sample of people who have experienced an NDE. In the present work, we sought to study the experience of ego dissolution and inflation in people who reported a classical NDE or NDE-like episode. To do this, we retrospectively administered the following questionnaires to assess their experience itself: (i) the NDE-C [7] to quantify the NDE(-like) phenomenology, (ii) the EDI [3] to explore the sense of ego dissolution potentially experienced during the NDE(-like), and (iii) the EII [3] to assess the experience of an ego inflation potentially experienced during the NDE(-like). Finally, we administered (iv) the Nature-Relatedness Scale (NR-6; [31]) to evaluate the participants’ potential subjective sense of connectedness with nature that they experienced at the time of the study. This trait-like construct was thus measured retrospectively to their NDE. Since we cannot currently distinguish between classical NDEs and NDE-like episodes (i.e., the studies conducted so far did not find differences in terms of intensity or frequency of core features when comparing both groups; e.g., [6,7]), we did not expect significant differences between classical NDE experiencers’ and NDE-like experiencers’ responses to these questionnaires. However, given that very few empirical articles include a group of NDE-like experiencers and that these experiences emerge in distinct contexts, we decided to examine differences between both subgroups of participants. We predicted NDE experiencers to score higher on the EDI than on the EII and positive correlations of the self-reported richness of NDEs (i.e., NDE-C scale total score) with the experience of ego dissolution (i.e., EDI total score) and connectedness with nature (i.e., NR-6 total score). Finally, we explored the relationship of two NDE features associated with ego dissolution, namely OBEs and experiences of unity with a larger whole. OBE and unity are two specific items contained within the NDE-C.

The present study sought to retrospectively explore the frequency and intensity of the experience of ego dissolution and inflation during NDEs. We observed higher EDI total scores compared with EII total scores in our sample of experiencers. Indeed, higher EDI total scores were more common than low EDI total scores, whereas it was the opposite trend for the EII: low EII total scores were more common than higher EII total scores. The results also revealed that higher scores of NDE ‘richness’ were associated with higher EDI total scores. In other words, the richness of the NDE was strongly (r = 0.55) associated with the subjective intensity of the experience of ego dissolution. Interestingly, the experience of ego dissolution retrospectively reported by our participants is rather intense on average (median of 67/100 on the EDI) and comparable to what is reported after ingestion of psychedelics (e.g., 46/100 reported during a DMT-induced psychedelic experience in [23]; 74/100 reported after a 5-MeO-DMT-induced psychedelic experience in [34]; 41/100 reported after lysergic acid diethylamide [LSD] in [3]; 52/100 reported after psilocybin intake in [35]). However, no direct comparison regarding the experience of ego dissolution between NDE and drug-induced psychedelic experiences has been carried out yet. As a matter of fact, it would be interesting to directly compare the sense of self experienced in NDEs and psychedelic experiences using a sample of people who experienced both types of experiences. Moreover, we observed that the intensity of the experience of ego dissolution was positively correlated with the sense of harmony/unity experienced during the NDE (r = 0.44), as if they belonged to a related construct or phenomenon. One can hypothesize that this feature may be experienced as an inevitable counterpart of the experience of ego dissolution; the blurring of personal boundaries could thus lead to feelings of belonging to a larger whole or ‘unity’, as discussed elsewhere [3,20].

Even though an intense experience of ego inflation was not commonly reported by our participants, the richness of the NDE was also correlated (albeit less strongly; r = 0.34) with the experience of ego inflation. Our study shows that NDE experiencers may score more than 0 (i.e., suggesting a minimum of disturbance of the sense as compared to their normally well-circumscribed experience of self in daily life) on both scales (the EDI and EII); however, we found higher EDI total scores compared with EII total scores in our participants’ sample. Nonetheless, our study does not permit to know more precisely when and how each type of ego experience has occurred within the NDE itself where many features are experienced. Although researchers from various fields have recently generated considerable interest in NDEs, the study of the sense of self in NDEs, in particular, has not received much attention yet. Further studies are necessary to explore this question.

OBEs are reported here by 87% of the sample of experiencers. This is consistent with the literature indicating that OBE is the second most commonly encountered feature in NDEs (i.e., about 80%; [6,8,9,10]). As expected, we found that the more intense the OBE, the more intense the experience of ego dissolution (r = 0.44). This raises questions about the link between the potential breakdown of the sense of self and the OBE, even if our study does not permit conclusions about any causality. The correlation between the two was likely and expected due to the close link between the two phenomena [12]. Nonetheless, it is worth mentioning that OBEs may be related to different types of disturbance of the sense of self. Indeed, we can dissociate three types of experience of self: (i) self-identification with a body (“do I have a body? If so, what is my body?”), (ii) self-location in space (“where am I?”), and (iii) the visuospatial perspective we experience (“from where do I experience the world?”) [12,36]. Future studies should address the experience of disruptions of the sense of self during OBEs, which is (spontaneous or induced by drugs or practice such as meditation) not an uncommon occurrence (prevalence of around 9 to 12% in surveys of the general population; e.g., [37,38]).

We observed that both groups of experiences did not differ in terms of richness of the experience. This is consistent with our previous studies (e.g., [6,7,39]). Moreover, no difference was observed between their experience of ego dissolution and inflation. Our results provide additional empirical evidence that classical NDEs and NDE-like episodes are not dissimilar. If this is confirmed, one may hypothesize that neurophysiological mechanisms underlying NDEs could be activated spontaneously or in non-life-threatening situations where the physical threat is only perceived and not necessarily actual [30,40]. Our results suggest that the circumstances of occurrence (i.e., in or outside the context of a life-threatening circumstance) does not influence reports of ego dissolution. Nevertheless, future studies studying the sense of self in a larger sample of NDE-like experiencers are warranted to confirm our findings.

We observed that the subjective connection with nature reported by experiencers was associated with both the richness of the NDE and the experience of ego dissolution (r = 0.27 and r = 0.41, respectively). Relatedly, Nour and colleagues [13] have already shown that experiences of ego dissolution under a psychedelic are dose-dependently associated with ratings of connectedness to nature, a finding which has also been replicated in surveys [28,41] and controlled research [40] showing that acute psychedelic experiences of ego dissolution predicted greater nature connectedness, including in a causal fashion [41,42]. Regarding the present results, we can also hypothesize that people who feel more connected to nature may be more prone to experience an NDE(-like) episode, notably due to some traits such as an “openness to experience” trait. In the present study, the NR-6 was only administered retrospectively to the NDE(-like) experience, which happened some months or years ago though, thereby limiting our conclusion regarding any causality between NDEs/NDE-like experiences and the subjective sense of connectedness with nature. Future studies are necessary to investigate the impact of NDEs on the construct of nature-relatedness.

The most frequently reported changes after a classical NDE correspond to a more altruistic and spiritual attitude, an important personal understanding of life and self, decreased fear of death, as well as a trend towards less materialist values [10,43,44,45,46,47,48,49]. Psychedelic studies show similar long-term changes, such as reduced death anxiety and lasting improvements in well-being [21,50,51,52,53,54]. While the overlap between NDEs and psychedelic experiences have been reported in terms of phenomenology (e.g., [23,30]), no direct comparison between NDE and drug-induced psychedelic experiences regarding their long-term psychological effects has been carried out yet. Interesting questions to investigate include: what are the underlying neurobiological mechanisms potentially linking the two experiences? Do NDEs and psychedelic states reflect closely related brain states albeit via different means of induction? The recently proposed ‘pivotal mental states’ model [55] bears relevance here. This article proposes that the experience of ego dissolution is a common feature of NDEs and (high-dose) psychedelic states, characterized by a quality of consciousness that is profoundly less ego-centric. Recent fMRI findings suggest that the degree of ego dissolution correlates with increased global functional connectivity in some brain areas such as the angular gyrus [56] and with default mode network integrity [57]. Although this is speculative, these patterns may be considered a good candidate for neural correlates of the experience of ego dissolution experienced during NDE(-like) as well. It is worth noting that this is mostly inconsistent with the phenomenon of ego inflation. Nonetheless, still very little is known about the sense of self that may characterize the different altered states of consciousness that humans can experience; a possibility is that both experiences could potentially emerge within a single subjective experience and consequently may not necessarily be antithetical.

To date, there have not been any systematic studies focused on the broader life and psychological impact of NDE-like encounters. Connectedness to nature and nature exposure are associated with improved mental health outcomes [31,41]; thus, it would be interesting to assess whether classical NDEs and/or NDE-like episodes are also associated with improved mental health [48]. NDE-like phenomenology may be reproducible in laboratory settings using various techniques (e.g., hypnosis, syncope through hyperventilation and orthostasis and Valsalva maneuver; [58,59]). If these lab models are faithful to the naturalistic phenomena, they could offer a useful means of assessing the longer-term psychological sequelae of NDEs and NDE-like episodes, e.g., as has been carried out with lucid dreaming (e.g., [60]) and psychedelic treatment (e.g., [50]).

Existing literature suggests that disturbance in the sense of the self should be viewed along a continuum [18]. Usually, healthy people have a constant and coherent sense of being an “embodied self” which encompasses our emotions, thoughts, and actions, and is generally felt to be distinct from other people and separate from the external environment [61,62]). However, anomalies to this principle do not necessarily indicate underlying psychopathology [61], and are even highly valued (e.g., as conducive to insight) in certain spiritual traditions. Moreover, such phenomena can be transiently induced via experimental means [63,64,65], and indeed, the psychedelic drug state can be considered one such example. Given the relevance of self-consciousness to our understanding of human consciousness in particular, investigating the nature of self-disturbances promises to offer fundamental insights into the nature of consciousness.

It is important to acknowledge the limitations of this study. First, volunteers enrolled in the study were self-selected and hence might not be representative of the broader population. Second, our study was cross-sectional and relied on short self-report measures. As our aim was to assess the sense of self, we relied on retrospective subjective measures of first-person experiences; only the individuals who experienced the NDEs know “what it feels like” to have had such experiences. As with psychedelic experiences [66], it is common for NDEs to be described as ‘ineffable’ [7,46]. Here, we decided to use a closed questionnaire format rather than spontaneous written narratives or freely expressed reports. The advantage of this approach is our ability to quantitatively assess the relevant phenomena using validated measures, but the limitation is that this constrains free expression and potential new learnings about the relevant phenomena. Third, our participants were Western, thus limiting generalizability to other populations. Fourth, it seems that there is a large difference in group sizes between NDE and NDE-like experiencers. Given the specificity of this population, the recruitment of participants was arduous and we were limited in our recruitment. Future studies should include a larger group of NDE-like experiencers. Other limitations are the lack of medical information regarding the presence of a life-threatening event and the lack of control groups or conditions. The EDI and EII are completed using a visual analog scale in which the zero is defined as “No, not more than usually”, thus allowing comparison with their usual experience of self. Moreover, we would like to mention that some experiencers of the present sample were also involved in other published studies from our research group due to the relative scarcity of NDEs and the challenge to recruit NDE experiencers. Finally, the retrospective and correlational design of our study does not permit conclusions to be made about any causal pathway. Hence, the present results need to be interpreted cautiously.

This study suggests that the experience of ego dissolution is a common feature of NDEs. The richness of the NDE was positively correlated with the intensity of this experience of ego dissolution and, less strongly, with the intensity of the experience of ego inflation and subjective connection with nature. In addition, we observed a positive correlation between EDI total scores and the intensity of the OBE and the sense of unity. Overall, our results are in line with existing literature suggesting that mystical-type experiences, including NDEs, may feature important disturbances in ego-boundaries and highlight the fact that NDEs in particular can be considered as a probe to explore human (self) consciousness.

The authors wish to thank J.-P. Jourdan from IANDS France (www.iands-france.org↗ (accessed on 13 July 2021).) for their help in recruiting NDE testimonies.

C.M., S.L. and H.C. designed the study. C.M. and G.F. have followed data acquisitions. C.M. have analyzed the data. All authors have interpreted results and have drafted and revised the manuscript. All authors have read and agreed to the published version of the manuscript.

This research was funded by the BIAL Foundation, the Belgian National Funds for Scientific Research (FRS-FNRS), the University and University Hospital of Liège, the fund Léon Fredericq, the Society for Psychical Research, the Fund Generet, the King Baudouin Foundation, DOCMA project (EU-H2020-MSCA–RISE–778234), the AstraZeneca Foundation, the European Union’s Horizon 2020 Framework Programme for Research and Innovation under the Specific Grant Agreement No. 945539 (Human Brain Project SGA2), the European Space Agency (ESA) and the Belgian Federal Science Policy Office (BELSPO) in the framework of the PRODEX Programme, the Center-TBI project (FP7-HEALTH- 602150), the Public Utility Foundation ‘Université Européenne du Travail’, “Fondazione Europea di Ricerca Biomedica”, the Mind-Care Foundation, the Mind Science Foundation and the European Commission. O.G. is research associate and S.L. is research director at the F.R.S-FNRS.

The study was conducted according to the guidelines of the Declaration of Helsinki (1964) and its later amendments, and approved the Ethics Committee of the Faculty of Medicine of the University of Liège (Code: 2013/192).

Informed consent was obtained from all subjects involved in the study.

Some or all data used during the study are available from the corresponding author by request.

The authors declare no conflict of interest.