I know your red flags are up. What does neuroscience have to do with spirituality, and what in the world is neurospirituality? Before we dive in, you must understand this is absolutely treacherous territory for science to venture into—and no less that psychedelics are implicated, as well. While it’s dangerous to discuss the realms of science and spirituality interacting, it’s not entirely impossible as long as you know exactly who Stephen Jay Gould is.
Paleontologist Stephen Jay Gould could have stopped all his work in 1981 after releasing his seminal title, The Mismeasure of Man, which dispelled the racist ideology of phrenology (the study of how shape and size of the cranium indicate mental capacity or character). Gould has been lauded as one of the greatest modern scientists that ever lived. After all, not many scientists get the opportunity to play themselves in a Simpsons episode. But in 1999, he went on to release Rocks of Ages: Science and Religion in the Fullness of Life, in which he introduced to the world the notion that science and religion could coexist, an idea he called Non-Overlapping Magisteria (NOMA).
NOMA works on the simple principle that science and the belief in spirituality can coexist while also inhabiting two completely separate domains, known as magisteriums. Gould believed science should not outwardly try to prove religion, and religion shouldn’t be utilized to alter the progression of science. Rather, he posited, they are two separate areas of life that often interact, but are distinctly different in nature. In theory, this works in harmony—until you throw a little neuroscience in the mix and the fundamentals of NOMA suddenly destabilize. This is the basis of neurospirituality—the brain mechanisms behind spirituality and religion. but we’re also interested in how psychedelics interplay with this emerging field. There is a historical precedent to all of this—and it begins with Timothy Leary.
The Good Friday Experiment
In 1962, Boston seminary students were given 30mg of psilocybin or placebo just before the Good Friday service, a day prior to Easter in which Christians refrain from eating meat. Although all twenty participants were white men, the study took place inside Boston University’s Marsh Chapel, which was headed by Howard Thurman, one of Martin Luther King Jr’s most notable mentors. The entire experiment was conducted by Harvard PhD student Walter N. Pahnke (with assistance from Timothy Leary). Participants were placed in the basement of Marsh Chapel while simultaneously a passionate Good Friday sermon held upstairs by Thurman was broadcast on a television in the basement. As expected, the double-blind aspect of the experiment went out the window quickly when it became obvious who was tripping out of the group. Nearly all participants who were administered psilocybin had significant mystical experiences that marked a critical pivot in their life.
Twenty-five years after this experiment, Rick Doblin tracked down nearly all the participants, and most stated that the Good Friday experiment was “one of the high points of their spiritual life.” One participant said:
“It left me with a completely unquestioned certainty that there is an environment bigger than the one I’m conscious of. I have my own interpretation of what that is, but it went from a theoretical proposition to an experiential one.”
Neurological Underpinnings of a Mystical Experience
A lot has changed since 1962. Humans walked on the moon, Street Fighter 2 was released in arcades, and fMRI technology was created to give humans clear spatial definition of the brain. With this, came the discovery of the Default Mode Network (DMN), a brain network that essentially comprises the seat of the ego and has been implicated in many psychedelic experiments. The DMN plays a crucial role in the development of social functionality, the perception of time, remembering the past and simulating the future, and the separation of “self” and “other.”
Within the DMN is the cingulate cortex and the medial prefrontal cortex, which are both rich in serotonin receptors, and which also happens to be the postsynaptic site of psychedelic activation. Under the influence of a psychedelic, these two areas do a dance called decoupling, which is less of a dance and more of an edging away from each other. Under acute psychedelic doses, when these two areas within the DMN lose integrity (or decouple from each other) the subjective experience generally falls into the scientific category of “oceanic boundless,” a feeling of oneness that refers to the “dissolution of ego boundaries associated with positive emotions ranging from heightened mood to sublime happiness and serenity or grandiosity.” This sense of oceanic boundlessness is also part and parcel of the “mystical experience,” which has been defined by psychedelic scientists according to various criteria, including a sense of oneness, transcendence of time and space, a noetic quality, and a deeply felt positive mood. These psychedelic experiences are often categorized by having components of “otherworldliness,” like feeling a presence greater than yourself.
These neurochemical shifts within the DMN are usually a precursor to religiously induced or psychedelically induced spiritual or mystical experiences. If you’ve read my work, then you’re well aware of the extent to which the DMN is implicated in a variety of subjective psychedelic experiences. The DMN is almost always implicated when a person has extraordinarily intense trips on any psychedelic. However I’ve often questioned whether the DMN is as integral to the psychedelic experience as we think it is, or if focusing on the DMN is simply the best solution we have right now in this early stage of psychedelic science. According to Michael Van Elk, a professor in the cognitive psychology department at the University of Leiden and the founder of PRISM (Psychedelic, Religious, Spiritual and Mystical) lab, the “fact that the DMN is popping up in all these different domains is more related to the way we set up our studies and the limitations of the neuroimaging techniques that we use.” He adds that the DMN is also often used in a reverse-inference based reasoning, such as, “’Hey, we see a reduced activity in the DMN, so the person must be less focused on the self.’ We already know that these types of inferences are highly problematic for many reasons: One is that a single brain network can perform many different functions and there is simply no one-to-one mapping between network and function—otherwise we end up with good old phrenology.”
Van Elk brings up a great point. Just because the Default Mode Network has been heavily implicated in psychedelic science doesn’t necessarily mean that alterations within the DMN are exclusively reserved for psychedelic modulation. The brain isn’t that simple—and the last thing we need psychedelics to do is spark a resurgence in phrenology. Been there, done that, and the field of neuroscience suffered a massive setback. In the 19th century, scientists thought bumps on our head corresponded to our behavior and intelligence. This naive understanding of the brain led people to make wildly-absurd and incorrect (and often racist) assumptions based on ethnicity and gender. Neurospirutality doesn’t do this. It takes an innovative approach to discerning spiritual acceptance through techniques like brain lesion network mapping.
Neurospirituality Explained: The Brain on Spirituality
Spirituality is defined as the belief or acceptance that certain actions and events within an otherwise rational reality are the result of forces that are impossible to explain with objective reasoning. Another definition of spirituality involves the idea that existence is linked to a purpose that’s usually defined in a reality outside our physical universe. Neurospirituality, on the other hand, is the study of the neurological mechanisms of spirituality within an individual. It’s not my idea, it belongs to Michael Ferguson at Harvard Divinity School. He started his pursuit of objectively measuring spirituality when in a 2018 study he placed devout Mormons under task-based fMRI, a neuroimaging process that reveals connectivity in the brain while conducting a certain action. That action was pushing a button every time they felt the “spirit” through prayer. Latter-day Saint (LDS), or Mormon, spiritual life is so amenable to task-based fMRI, Ferguson explained, “is that LDS people routinely report to one another in real time when they are ‘feeling the Spirit.’ The fact that this type of spiritual self-awareness and reporting is commonplace within LDS religious culture makes LDS spiritual practice a perfect match for task-based fMRI.”
Ferguson found brain activation in their nucleus accumbens, medial prefrontal cortex, and frontal attentional regions. Some of those areas you’ve probably never heard of, but there’s a good chance you’ve heard of the medial prefrontal cortex before. It’s an active part of the Default Mode Network.
Neurospirutality really came to the forefront after Ferguson conducted “lesion network mapping” on a group of participants. Through a complex array of datasets of patients who had brain lesions due to surgery, along with accompanying questionnaires given just after and in some cases decades after the surgery, Ferguson was able to identify brain networks like the Central Executive Network (CEN), also known as the Fronto-Parietal Network (FPN), and its relation to another part of the brain called the Periaqueductal Grey (PAG), which sounds like a desperate color in a box of crayons. Science is all about acronyms.
Your PAG generally has an inverse relation with your CEN, which means your PAG and CEN don’t have functional connectivity—almost like two neighbors who keep the peace, but never invite each other over to share a joint. The CEN is an area in the brain generally responsible for goal-oriented behavior and problem-solving. When it comes to intense cognitive tasks that require focus, the CEN is the area. The PAG is a small area of the brain: It’s actually the fluid that surrounds the cerebral aqueduct in the midbrain and is pretty vital for things like compassion, empathy, and the inhibition of pain. Ferguson found that the people in his study who had the least acceptance of the role of spirituality in their lives generally had lesions that sat on top of areas known for high functional connectivity with the PAG, like the amygdala and other areas of the Default Mode Network. Interestingly, people who had lesions that were on areas of the brain that had a little to no connectivity with the PAG (like the Central Executive Network) also showed an increase in spiritual acceptance that was measured by the Temperament and Character Inventory (TCI), a test that measures personality traits. The network that would normally inhibit spirituality was now going full throttle in the opposite direction; Ferguson likened it to a moving car without the brakes. People who had lesions in this area were experiencing hyperreligiosity (a psychiatric condition in which intense religious beliefs may impact a person’s normal functioning). A positive functional connection between a brain lesion and the CEN indicated increased spiritual acceptance.
Correlations Between Neurospirituality and Psychedelics
The only neuroscience study I could find about psychedelics’ relationship with the periaqueductal grey comes from research published in August 1999 by Martina Erdtmann-Vourliotis and Peter Mayer at Otto von Guericke University Magdeburg. They found that LSD and MDMA had high neuronal activity in the periaqueductal grey, the same area identified by Michael Ferguson in neurospirituality two decades later. They hypothesized this could be due to the ample amounts of serotonin in the PAG, the neuro neuromodulator released while tripping on classic psychedelics.
Surprisingly, another part of the brain Ferguson discussed in his investigation into neurospirituality was also identified in this same study. Researchers found that with LSD and MDMA, and even modestly with THC, there is high neuronal activity in the nucleus accumbens, an area of the brain involved in the sensation of pleasure. (On the other hand, substances like cocaine and morphine had a low activity in the nucleus accumbens). Ferugson also saw this nucleus accumbens correlation when patients reported feelings of spiritual acceptance. The same part of the brain, the nucleus accumbens, is active while a person is tripping on psychedelics and when a person is inclined to accept spirituality into their lives.
How do you measure psychedelic-induced spirituality?
Neuroimaging, which looks at blood flow within the brain, is responsible for most of our understanding of how psychedelics interact with the brain. It also gives us a better understanding of the many brain areas that are active when a person is embracing spirituality. However there are other measurements that can tell us more about psychedelics and spirituality.
Psychology uses the Five Dimensions of Altered States of Consciousness (5D-ASC) to assess the quality and direction of a psychedelic trip. The 5D-ASC was invented by Adolf Dittrich and evaluates the strength of a psychedelic trip based on areas of “visionary restructuralization”’ (which includes seeing complex and imagery and audio-visual synesthesia), oceanic boundlessness, and anxious ego-dissolution (feeling of anxiety and disembodiment). This is what the 5D-ASC scale looks like when participants are given varying doses, ranging from 75μgto 200μg, of LSD, compliments of Dr. Liechti.
Notice there is a “spiritual experience” metric, but it only occupies one of eleven measurements on this scale. The 5D-ASC was constructed around the psychedelic experience, but there is another scale specifically built for spiritual experiences, called the mystical experience questionnaire.
The Mystical Experience Questionnaire (MEQ) was created by Pahnke (same researcher from the Good Friday experiment) and was designed to analyze psychedelic-induced mystical and spiritual experiences. More recently, the Hood Mysticism scale is a 32-question test that developed to classify the mystical experience into three categories: extrovertive mysticism, introvertive mysticism, and religious interpretation. Extrovertive mysticism is when one finds unity with the vastness of the physical universe and everyone (and everything) within it. Ideas like “we are all one” fit into this category. Introvertive mysticism works on the principle that the physical universe and all that’s within it must be removed or transcended in order to experience “oneness with nothingness.” Religious interpretation is a third factor that accounts for spirituality as expressed by a person’s specific religion. Interpretation can alter expressions of extrovertive and introvertive mysticism, but it has been suggested that the core of mystical experiences exist independent of any religious interpretation. Still, according to Van Elk, new psychometric scales need to be created to evaluate a psychedelic trip.
“I think the field is in need of newer and better instruments and scales to assess what happens during a psychedelic experience. Many of the existing instruments are heavily theory-laden and bring in specific assumptions as of how a psychedelic experience should be viewed and interpreted. For instance, the M-scale is directly inspired based on the perennialist philosophy of Walter Stace and Aldous Huxley. On the other hand, scales like the 5D-ASC might miss out on aspects of the experience that still seem important to many people who’ve had these experiences.”
In Huxley’s The Perennial Philosophy, he suggests that all world religions share a single mystical origin or universal truth. It’s like a unifying theory of mysticism—and it was inspired by Huxley’s use of psychedelics.
There have been attempts to integrate both the MEQ and the Hood Mysticism Scale like the MEQ30, but as psychedelic science gets more complex new quantification methods will be needed. We may even get to the point in which each psychedelic substance has its very own psychedelic-mysticism assessment scale.
Science is only as accurate as the measurements it can obtain. Our understanding of neurospirituality and psychedelics is still poorly understood by science (so much so, that most of you never heard of the term neurospirituality prior to reading this article). All of this is fairly new, and never before in history have we had the tools to discover scientific biomarkers of the subjective experience of a spiritual experience induced by psychedelics.
The Future of Psychedelics and Spirituality
The investigation of psychedelics and spirituality would be relatively at the same place it was since the Sixties without the advent of novel neuroimaging techniques like fMRI and the subsequent discovery of entire brain networks like the Default Mode Network and the Central Executive Network, both of which are heavily modulated by psychedelics. The reason why Michael Ferguson’s work in the realm of neurospirutality is so ground-breaking is that it represents the first time in which we can visualize the spiritual experience within the brain. At the time of writing this, Ferguson’s neurospirituality is entirely focused on spirituality obtained from religion—while psychedelic-induced mysticism and spiritual acceptance have not been evaluated. In fact, this article is the first to potentiate the possibility of neurospirutality being implemented in the psychedelic space.
There are more questions than answers at this point regarding what psychedelics can bring to the idea of neurospirituality. Sure it’s a delicate conversation that has an enormous amount of pitfalls if not done properly, but that doesn’t mean science (or religion) should shy away from it. An interesting angle emerges when you bring in the objectiveness of psychedelics (serotonin receptors in the brain activating) combined with the subjective experience of psychedelics (seeing or communicating with a grandiose force). We know people have mystical experiences as a direct result of taking an acute dose of psychedelics. The neurological correlations of this phenomena have been seen in a multitude of neuroimaging studies over just under a decade. However, being able to see spirituality increase or decline from the suppression of certain areas of the brain through neurospirituality is completely new to humanity—so new that Ferguson began teaching his first class on neurospirituality at Harvard this Fall.
It’s also important to note that not every psychedelic experience is mystical, and just because a person has spiritual tendencies doesn’t mean they have a lack of cognition due to certain areas activating (or suppressing other areas). Like Van Elk mentioned, we don’t want to go down a path of phrenology when determining the quantification of the spiritual experience and how psychedelics can induce it. The brain is more complex than we can imagine, yet with each quality scientific study, we’re slowly chipping away at this enigma that’s trapped inside all of our heads—and with each psychedelic trip, our understanding of neural activities gets even more complex.