A near-death experience (NDE) is a reported memory of a pattern of experiences that can occur when a person is close to dying (e.g. life-threatening situations, asphyxia, near-drowning, stroke, etc.), when they believe they are close to dying (e.g. shock due to loss of blood) and in the period between clinical death and resuscitation (e.g. due to cardiac arrest) (van Lommel
). NDEs have also been reported as occurring in non-life-threatening situations such as during grief and anxiety, epilepsy, syncope and Cotard’s syndrome (Charland-Verville et al.
). NDEs are often transformational, prompting (for example) enhanced intuitive sensibility; changes in life insight; greater understanding of self; and changes in spiritual and/or religious beliefs (Khanna and Greyson
; Schwaninger et al.
). Approximately 4% of adults in Western countries have experienced at least one NDE, although prevalence estimates should be treated with caution because the primary means of identifying NDEs is via self-report (e.g. individuals may be reluctant to share their experience following an NDE) (van Lommel
Although individual, cultural and religious factors influence the vocabulary individuals use to describe and interpret their NDEs, consensual scientific opinion appears to be that there is little variation in the components of NDEs (van Lommel et al.
). More specifically, NDEs are understood to involve one or a combination of the following features: (i) an out-of-body experience (OBE), (ii) seeing or moving through a tunnel, (iii) communicating with a being of light, (iv) observing a celestial landscape, (v) meeting with deceased persons, (vi) a life review, (vii) loss of sense of time and space and/or (viii) a conscious return to the body (Schwaninger et al.
; van Lommel
The typical format of NDE studies in human participants is that it follows either a retrospective (i.e. asking participants about their experience of a prior NDE) or prospective (i.e. exploring how participants’ life and perspective changes following NDEs) design. The principal reason for this is that NDEs typically occur unexpectedly, and concurrently assessing brain activity whilst an individual is experiencing an NDE would give rise to numerous logistical as well as ethical challenges. However, there does exist an electroencephalogram (EEG) study monitoring brain activity in rats following clinical death induced by euthanasia (Borjigin et al.
). In this study, EEG recordings identified four distinct stages of brain death: (i) cardiac arrest reflecting the time (~ 4 s) between the last regular heartbeat and the loss of an oxygenated blood pulse (i.e. clinical death; stage 1), (ii) a burst in low-frequency brain waves (~ 6 s; stage 2), (iii) increase in high-frequency gamma activity (~ 20 s; stage 3) and (iv) cessation of meaningful brain activity (stage 4). According to the study authors, the high-frequency neurophysiological activity in the near-death state (i.e. stage 3) exceeded levels found during the conscious waking state and may be similar to the highly lucid mental experiences reported by human near-death survivors.
Clearly, the extent to which findings from the aforementioned study using rats can be generalised to human participants remains highly questionable. However, in the absence of research examining human brain activity during an NDE episode, studies using mammals provide potentially useful information to guide future empirical enquiry. Another area of research that may help inform understanding of NDEs in human participants is studies assessing the neural correlates and wider participant experiences of meditation. For example, a sense of separation from the body, alterations in time and space perception and encountering mystical beings are experiences that have all been reported during meditation (Kundi
). Furthermore, increased gamma-band activity (i.e. similar to outcomes of the aforementioned rat study) has been observed in advanced Buddhist meditation practitioners both during and following meditation (Lutz et al.
). Indeed, when meditators were asked to mentally visualise and emotionally connect with encountering a “being of light” typical of an NDE, they displayed greater gamma activity and other neuro-electric changes in brain regions associated with positive emotions, imagery, attention and spiritual experiences (Beauregard et al.
The practice of using meditation to derive a better understanding of death is longstanding. This is particularly the case in Buddhism where ancient texts exist that describe meditation practices specifically intended to help spiritual practitioners prepare for, or gain insight into, the processes of dying and death. An example that has gained some popularity in the West is the eighth-century
Tibetan Book of the Dead
) along with more recent adaptations such as the
Tibetan Book of Living and Dying
). A related (but less well-known) text by the same eighth-century author is the
Profound Dharma of Natural Liberation Through Contemplating the Peaceful and Wrathful: Stage of Completion Instructions on the Six Bardos
). These texts outline specific phases that the consciousness is purported to progress through during and following death.
Another notable Tibetan Buddhist text is
Delok: Journey to the Realms Beyond Death
) that recounts the author’s experience of being a
. According to Tibetan Buddhism,
are individuals that experience (sometimes lasting hours or even days) NDEs and subsequently share their experiences as a means of assisting other spiritual practitioners (Baily
). In line with the content of each of the aforementioned Tibetan Buddhist works, the Dalai Lama (
) asserted that at the moment of death, a state of consciousness briefly manifests in all human beings which has the properties of being subtle, spontaneous, and without self-grasping. The Dalai Lama (
) also asserted that experienced meditators can deliberately induce this state during meditation such that when it naturally occurs at death, they can recognise and sustain it.
Additional relevant texts that exert a key role in Theravada Buddhism are the
Each of these discourses contains the
nine charnel ground contemplations
that are intended to help the meditation practitioner move beyond being attached to their body and gain insight into the processes of decomposition and dissolution that occur during and following death (Shonin and Van Gordon
). Other Theravada Buddhist texts such as the
acknowledge the existence of the
which can be interpreted as the “external consciousness” or “aspiring consciousness” that manifests after death (Anālayo
). Furthermore, accounts of the Buddha guiding his disciples to experience the hells and other realms of existence could also arguably be interpreted as a form of NDE.
There are several documented explanations as to why some Buddhist practitioners engage in meditation techniques intended to foster familiarisation with death. A key reason is to overcome attachment to the body and to the idea that the “self” exists as an enduring, independent entity (Sogyal
). More specifically, Buddhism asserts that suffering arises as a result of an individual’s “attachment” to both themselves and external phenomena (e.g. wealth, people, reputation, etc.; Feliu-Soler et al.
). The Buddhist notion of attachment has been defined as “the over-allocation of cognitive and emotional resources towards a particular object, construct, or idea to the extent that the object is assigned an attractive quality that is unrealistic and that exceeds its intrinsic worth” (Shonin et al.
, p. 126). Consequently, in the Buddhist meditation literature, reducing attachment (or augmenting non-attachment) is deemed to be an important feature of the path to psycho-spiritual wellbeing (Van Gordon et al.
). A second reason for increasing familiarity with death is that given it is a process that affects every living being, it is arguably wise to prepare for and/or try to understand it (Shonin and Van Gordon
). Furthermore, some Buddhist practitioners use meditation to induce so-called mystical experiences (i.e. such as those that comprise NDEs) in order to understand that such experiences are, in fact, not mystical but are “normal” dimensions of the mind and reality that can be accessed through meditation (Shonin et al.
Thus, in Tibetan Buddhism and to a lesser extent in other Buddhist traditions such as Theravada Buddhism, there exists the view that some advanced meditators can use meditation in order to gain insight into the state of consciousness that manifests after death. However, to date, no study has empirically investigated the phenomenon of the meditation-induced near-death experience (MI-NDE). Consequently, the following questions remain unanswered: (i) Are the MI-NDEs referred to in ancient Buddhist texts still experienced by advanced meditation practitioners today (i.e. does the MI-NDE exist as an empirically investigable phenomenon)?, (ii) What are the defining features of MI-NDEs and do they meet the criteria of a conventional NDE?, (iii) Is there a relationship between the duration and profundity of an MI-NDE?, (iv) Does familiarisation with the MI-NDE over time lead to more lucid and/or profound experiences of the after-death state? and (v) How can MI-NDEs advance scientific understanding of the NDE phenomenon and of the dying process more generally? The present study sought to address these questions by quantitatively assessing changes in the content and profundity of MI-NDEs elicited by advanced Buddhist meditators over a 3-year period (study 1) and employing qualitative analytical techniques (study 2) to identify common themes in terms of meditators’ experiences of the MI-NDE.
The present study employed mixed-methods and recruited advanced Buddhist meditators in order to conduct an initial empirical investigation of MI-NDEs. Compared to two control conditions that involved standard meditations without inducing an NDE, the MI-NDE condition prompted significantly greater pre-post increases in NDE profundity, mystical experiences and non-attachment. Furthermore, participants demonstrated significant increases in NDE profundity across the longitudinal 3-year study period. No significant relationship was observed between NDE profundity and duration of MI-NDE. Findings from the qualitative study demonstrated that participants (i) were consciously aware of experiencing an NDE, (ii) retained volitional control over the content and duration of the MI-NDE and (iii) elicited a rich array of non-worldly encounters and spiritual experiences.
Scores on the NDE Scale for the MI-NDE condition were considerably higher than the cut-off score for an NDE (i.e. ≥ 7; Greyson
) and ranged between 24 and 30 (total permissible range = 0–32). In conjunction with the sizeable difference in NDE Scale scores between the MI-NDE and control conditions (range for control meditation conditions = 6–10), this suggests that participants experienced a genuine form of NDE and that outcomes relating to the MI-NDE condition were not simply the product of a standard or profound form of meditation. Thus, it appears that the MI-NDE referred to in ancient Buddhist texts (i) exists as an empirically investigable phenomenon and (ii) is a valid form of NDE according to conventional assessment criteria. Furthermore, the fact that pre-post scores for mysticism and non-attachment were significantly greater for the MI-NDE versus control conditions demonstrates that the MI-NDE was more “spiritually potent” compared to standard meditation practices. This is consistent with findings from studies of “regular” NDEs that have reported significant gains in spiritual insights and awareness following an NDE (Khanna and Greyson
Given that NDEs (whether regular or meditation-induced) elicit spiritually meaningful insights, it is unsurprising in the present study that NDE profundity increased over time. This outcome is likely to be a function of “practice makes perfect” and participants continuing to refine the meditative skills that they employ whilst engaging in, and directing the content of, NDEs. However, no significant relationship was observed in the present study between NDE profundity and duration of a particular MI-NDE session. This accords with findings of no relationship between length of unconsciousness and perceived length of NDE from studies of medically caused NDEs (Parnia et al.
). A plausible explanation is provided in the Buddhist literature where some Buddhist teachers assert that for the spiritually adept (i) a single second can be experienced as a lifetime and (ii) the present moment is continuously changing and never actually crystallises into existence (i.e. it exists only as a relative concept) (Shonin and Van Gordon
). Thus, the absence of a significant relationship between NDE profundity and duration appears to support claims in both the Buddhist and empirical NDE literature that conventional limits of time do not apply during NDEs (Sogyal
; van Lommel
). This is consistent with the outcomes from the qualitative analysis conducted as part of the present study where participants reported that they experienced “timeless time” during the MI-NDE.
Study outcomes demonstrated both convergent and divergent factors in terms of the degree to which the MI-NDE differs from a regular NDE. Almost all of the 16 items on the NDE Scale received affirmative responses (i.e. 1 = mildly/ambiguously present or 2 = definitely present) by the majority of participants, suggesting that the features referred to in the NDE Scale (e.g. timelessness, OBE, encountering non-worldly realms and beings, feelings of immense peace and being united with the universe, etc.) also arise during an MI-NDE. The only exception to this was Item 2 (Were your thoughts speeded up?) that did not receive a single affirmative response. Furthermore, no participant responded with a score of 2 (i.e. feature definitely present) to Item 16 (Did you come to a border or point of no return?). A feasible explanation for these observations is that in order to reach advanced stages of meditative development, Buddhist meditators have to embrace the principle of “boundlessness” and seek to transcend relative concepts such as time and space (Van Gordon et al.
). Thus, in line with the aforementioned qualitative outcomes where participants reported experiencing “timeless time” and “spaceless space”, it is perhaps understandable why the present sample of advanced meditators did not provide affirmative responses to questions relating to spatial borders and/or the speeding up of psychological processes (i.e. because the concept of “speeding up” becomes redundant in the absence of time).
The qualitative analysis also identified a number of MI-NDE features that have not to date been recognised as a common feature of a regular NDE. More specifically, it appears that the MI-NDE can be distinguished from the NDE due to the fact (i) it can be consciously induced; (ii) participants retain volitional control over the content and duration of the MI-NDE; (iii) in the early stages of the MI-NDE, there manifests a phase—involving a sequence of visions and sensations—that participants attribute to becoming “untied” from the natural elements; (iv) participants retain a partial awareness over their worldly physical body; (v) participants experience scenes from past lifetimes (i.e. rather than only their current life); and (vi) participants perceive the content of the MI-NDE to be of the nature of “emptiness” and, in some cases, an expression or creation of their own mind.
None of the abovementioned MI-NDE features contradict or are incompatible with the established features of a regular NDE. Rather, we would argue that they add novel dimensions to the NDE and that their occurrence can be attributed to the fact that participants—all of whom were advanced Buddhist meditators—have dedicated decades of their lives to accruing meditative experience (as previously reported, on average, participants had practiced meditation for nearly 30 years and engaged in the MI-NDE practice three times per year). In other words, cultivating and refining the meditative and metacognitive skills to induce, and retain volitional control over NDEs, is inevitably going to afford individuals greater possibilities in terms of the range of NDE features they can experience. Furthermore, unlike regular NDEs where individuals are generally unconscious and only become aware of the fact they have experienced an NDE after the event (van Lommel
), participants in the present study reported that they retained meditative awareness throughout the entire NDE episode. Therefore, the participants’ recollection of the MI-NDE—that in many cases was captured within 24 h of the MI-NDE concluding—is likely to be less subject to recall bias.
Although findings from the present study appear to extend the component features of the NDE, they should be considered in light of their limitations. Of particular note is that some participant scores on the NDE Scale for the two control meditation conditions slightly exceeded the threshold (i.e. ≥ 7) for an NDE (standard meditation = 7.17 [SD = 1.34], standard meditation with death contemplation = 8.0 [SD = 1.28]). One explanation for this could be that participants were not familiar with the NDE experience at the high end of the continuum, and thus over-rated the intensity of their experience. Furthermore, as previously discussed, a small number of items on the NDE Scale did not receive a single affirmative response and, based on outcomes elicited during the qualitative analysis, appeared to be incongruous with some core Buddhist meditative principles. In the absence of a scale specifically designed to assess MI-NDEs (i.e. because until now the content of an MI-NDE has not been empirically defined), the NDE Scale was administered in the present study as it was deemed to have sufficient face validity to serve as a rudimentary assessment for an MI-NDE. However, the scale may not have adequate specificity in terms of differentiating between experiences arising during meditation versus those arising during NDEs. Furthermore, it may not accurately assess the profundity or full range of experiences that can arise during an MI-NDE. Additional study limitations were the fact that (i) participant experiences were exclusively assessed using self-report measures, (ii) the sample size was understandably small (i.e. because very few individuals possess the meditative experience necessary to induce an NDE during meditation) and (iii) the sample exclusively comprised Buddhist meditation practitioners meaning that interpretations of the MI-NDE arising due to religious predispositions were not controlled for.
The present study appears to confirm the existence of the MI-NDE referred to in ancient Buddhist texts. Findings demonstrate that some advanced Buddhist meditation practitioners use the MI-NDE to foster insight into death-related processes as well as the nature of self and reality more generally. In addition to adding empirical support in terms of the established features of a regular NDE, findings indicate that there are potentially other interpretations of, as well as other dimensions to, NDEs. Whilst the MI-NDE appears to be a valid form of NDE according to conventional assessment criteria, further research is required to replicate the present findings as well as advance understanding of the features that distinguish an MI-NDE from a regular NDE. A key implication is that the present study indicates it would be feasible—including ethically feasible—for future research to recruit advanced meditators in order to assess real-time changes in neurological activity during NDEs. To date, the health risks and ethical challenges associated with conducting such a study in human participants (i.e. as they experience a regular NDE) have rendered this possibility untenable.