There is an automatic impulse, felt in all humans, to trust what we see. Whether it be recognizing the face of your mother or navigating the busy streets of a college campus, you inherently trust your eyes to guide you. So, what happens when other people can’t see what you do? How is it possible that, under the correct conditions, our minds can fabricate people, animals, or even spirits, out of nothing more than hormones and neurochemicals? And what makes these hallucinations any less tangible, or believable, than the reality we experience everyday?
Hallucinations are defined as experiences involving the apparent perception of something not present. Typically, hallucinations are discussed within the bounds of psychedelic drugs such as LSD, mushrooms, and in the northern regions of Mexico peyote, a spineless cactus that contains the hallucinogen mescaline is often used by indigenous groups during religious rites. Powerful psychedelics like these are known for their ability to alter our thoughts, mood, and perception, which is why they are often taken in the context of upbeat social events such as concerts and music festivals. However, there also seems to be a spiritual component to the use of psychedelics. Timothy Leary, an American philosopher and psychologist of the late 20th century who was an advocate of psychedelic use, took mushrooms on a trip to Mexico. His son, Zach, remembers that his father “learned more in [his] 4 hours on mushrooms (psilocybin) than [he] did in [his] previous 20 years in psychology” after taking mushrooms in Mexico (Have a Good Trip). Leary was such a strong proponent of psychedelics that he conducted psychedelic experiments with his grad students, ultimately leading to his termination from Harvard University in 1963. He believed that “psychologists and psychiatrists want to use LSD in treating mental illness. LSD will be the number one cure for mental illness when the psychologists know how to use it”. Another corroboration for the spiritual element of hallucinogens is described by the musician Sting, who said that the psychedelic experience “takes the ‘it’ out of ‘me and it’. It becomes ‘me and thou’…whether it’s a tree, or it’s a river, or it’s a piece of rock, you realize that you’re connected”. When reporting his use of peyote, in the Netflix documentary Have a Good Trip: Adventures in Psychedelics, Sting claims that “everything was alive…the grass started talking to me…the trees are waving kinda musically at me…what the experience does, is it presents you with the idea of mortality, right here (points to his forehead), and you cannot dodge it. It’s your own mortality, the mortality of this planet…that is the central issue of consciousness”. While the reports of psychedelic experiences are wonderous in of themselves, psychedelics are not the only mediators of hallucinations.
There is a small fraction of people, those who have survived a Near Death Experience (NDE), who can share what it is like to have undergone an event that very few can relate to. A NDE is an unusual experience taking place on the brink of death and recounted by a person after recovery, typically an out-of-body experience or a vision of a tunnel of light. Many NDE survivors recall incredibly visceral and intense mystical-out-of-body experiences, mystical hallucinations, where they recall having interacted with benevolent ‘spirits from the heavens’. The mystical experiences reported from NDE survivors are strikingly similar to reported hallucinations resulting from the use of psychedelics. Psychedelic hallucinations and NDE induced hallucinations both tend to contain connections to nature, the heavens, and generally, the universe as a whole. In the Netflix series Surviving Death, one person describes NDEs as “blissful experiences in which they left their bodies and traveled to some other realm”. Another person, while telling his account of a NDE, said that “If I could touch a leaf, I became an aspect of that leaf…by having this opportunity, it truly healed my spirit” (Surviving Death). The parallels between NDE recollections and psychedelic experiences are uncanny, and may allude to them having similar neural origins. The intriguing part of NDE induced hallucinations is that these individuals claim to have had conscious experiences in the moments between death and resuscitation. So, what could be happening in their brains in the period of time after their hearts have stopped beating?
Officially, the mystical experiences the stem from NDEs can be defined as “peculiar states of consciousness in which the individual discovers himself to be one continuous process with God, with the Universe, with the Ground of Being, or whatever name he may use by cultural conditioning or personal preference for the ultimate and eternal reality” (Barrett, Frederick S., and Griffiths, 1970). Most research regarding spiritual, out-of-body experiences focuses on how psychedelic drugs can create pathways for these experiences; however, there is another category of mystical experience that doesn’t involve entheogens or alcohol at all. Many recordings of NDEs relay descriptions of religious or mystical experiences as well. In the case of mystical experiences induced by NDEs, these sacred encounters are all described in a relatively similar manner: there is a sense of time distortion, an unconditionally accepting being of light, a feeling of their ordinary senses being expanded, and typically after the event has occurred these individuals report that they are profoundly changed (Surviving Death). For these individuals, even after the body has died and there aren’t any brain waves active, they report incredibly visceral and welcoming experiences with the heavens before being tugged back into their bodies. According to Bruce Greyson, MD, in the Netflix documentary Surviving Death, somewhere between 10-20% of people whose hearts actually stop will report these dramatic near-death experiences. Stories reporting NDEs can be hard to believe because of the mainstream scientific idea that the physical world is all that exists, but maybe it is possible that the physical world is simply all that we know (Surviving Death).
When interviewing survivors of NDEs, there are a multitude of recollections that rise above typical experiences in the natural world. One survivor claims that the afterlife was “exploding with every color of the universe, there was an absolute shift of time and dimension. I experienced all of eternity in every second, and every second expanded into all of eternity” (Surviving Death). She even reported, “I could feel my spirit peeling away from my body…I was immediately greeted by this group of somethings…people, spirits, beings. I didn't recognize any of them, but they had been important to my life story somehow”. Her re-telling of her mystical experience follows a very similar trajectory to other NDE reports. In 1998, Raymond Moody, MD said that most “patients say they become aware of what’s described as a tunnel, a passageway, a portal, and they go into this tunnel. And when they come out, they come out into a very brilliant, warm, loving and accepting light” (Surviving Death). The commonalities of these NDE induced mystical experiences allude to the possibility of life after death; this ‘life’ would simply be a version of consciousness never experienced before, a life free of the bounds of the physical world as we’ve come to know it. Even more powerful is the fact that individuals of various religions and beliefs report similar experiences after temporary death, often unrelated to, or even disregarding, their religious origins.
I hypothesize that the root cause of the mystical hallucinations experienced during a NDE is related to serotonin and the 5HT2A (serotonin) receptors in our brains. The visual hallucinations connected to NDEs are very similar to the mystical or religious experiences induced by hallucinogenic drugs such as LSD or ‘magic mushrooms’ (psilocybin). Hallucinogens such as LSD are able to distort reality so vividly because they bind to various serotonin receptors in the brain with an agonist effect, meaning they mimic the effects of normally functioning serotonin receptors (Nichols, 2004). Serotonin is responsible for regulating mood, learning and reward systems, and is the primary neurochemical implicated in hallucinogenic research. Animal studies have shown that activating the 5HT2A receptors increases the excitability of the occipital cortex, creating pathways for visual hallucinations without external stimuli. These serotonin receptors mediate the visual hallucinations associated with psilocybin, and may also be responsible for the mystical experiences reported during NDEs (Kometer, Michael, et al., 2013). Recently, a new term is beginning to emerge colloquially in reference to psychedelics: entheogen. The appeal of the term entheogen is based in its etymology: entheogen stems from the Greek word ‘entheos’, meaning god within (Nichols, 2004). This new term suggests that there is a component to hallucinogenic drugs that mediates a connection to heavenly bodies.
One of the biggest questions raised while studying NDEs is what they might be able to tell us about the nature of consciousness. There is a common understanding that consciousness stems from brain activity, or more specifically, our ability to be aware of ourselves and the world we exist in originates in synaptic activity. Yet, if during an NDE “you get these very wide expansions of consciousness, even when the brain has ceased to function…it can’t be all brain” (Peter Fenwick MD, Surviving Death). Consciousness and the brain must be separate entities if it is true that one can exist without the other; however, this contradicts the basic understanding that in order to be conscious there needs to be an active brain at work. NDEs seem so incomprehensible as they raise more questions than answers. How do we know which came first, consciousness or the brain? Do they develop separately yet simultaneously, or are they irrevocably intertwined? Does consciousness exist somewhere outside of our minds, or is it restricted to the organ inside our skulls? While there are countless unknown variables, one thing is certain: consciousness is much more elusive and complex than we popularly consider it to be, and likely more complex than humanity will ever be able to understand.