Tuesday, February 20, 2024

Mystical Experience Through Ecstatic Epilepsy Triggered in the Anterior Insula

People with ecstatic epilepsy have epileptic auras in which they have mystical experiences.  In recent years, there has been growing evidence that this experience is triggered in the anterior insula in the temporal lobe of the brain.  This raises the question of whether all religious experience can be explained as rooted in the brain, and perhaps crucially in the anterior insula, as a product of the evolutionary history of the brain.  Does this show that there is a natural desire for religious experience as rooted in our evolved human nature?  If this is so, then we must wonder whether this is or is not a sign of the real existence of a transcendent realm of divinity that is the object of mystical experience.


To begin, despite the difficulties of definition in this whole area of human experience, we must define what we mean by mystical experience; and in doing that, we must also define religious experience in so far as it is rooted in mystical experience.  I have found William James in The Varieties of Religious Experience (1902) to be a helpful starting point.

James distinguished two branches of religion--institutional religion and personal religion.  Institutional religion is about theology, ceremony, and ecclesiastical organization, by which the social life of religious believers is structured--the external life of a religious group.  By contrast, personal religion is about the inner life of each believer as he conducts his own religious feelings, thoughts, and activities.  James chose to concentrate on personal religion because it seemed more fundamental than institutional religion.  Theological, ceremonial, and ecclesiastical traditions of every religion depend upon the personal religious experience of their founders.  For example, Paul is often considered the founder of the Christian church, but his authority to preach to the early Christian churches depended on his mystical experiences--such as his conversion on the road to Damascus--in which he saw and heard Jesus Christ and received a direct revelation from God.

James proposed:

"Religion, therefore, as I now ask you arbitrarily to take it, shall mean for us the feelings, acts, and experiences of individual men in their solitude, so far as they apprehend themselves to stand in relation to whatever they may consider the divine.  Since the relation may be either moral, physical, or ritual, it is evident that out of religion in the sense in which we take it, theologies, philosophies, and ecclesiastical organizations may secondarily grow" (James 1987: 36).

He then proposed defining mysticism as having four marks.  1.  Ineffability:  By this negative trait, no mystical experience can be adequately reported in words, because it can be known only by direct experience--by being felt rather than understood.  2.  Noetic quality:  Although it is a state of feeling, a mystical experience does convey a profound mental clarity or revelation of the deepest truths about the universe, often an ecstatic sense of oneness with Everything or the Transcendent Order.  3.  Transiency:  Mystical states can be experienced for only brief periods of time--from a few minutes to an hour or two.  4.  Passivity:  Although mystical states can be facilitated by exercises such as meditation, prayer, and reading of spiritual texts, when the mystical consciousness arises, it feels as though it was compelled by a higher power beyond the person's will (James 1987: 343-44).


Ecstatic epilepsy is a rare form of focal epilepsy in which people have mystical experiences during the aura before the onset of convulsive epileptic seizures (Picard 2023).  (In Greek, ekstasis means "standing outside oneself.")  Epilepsy affects a small minority (between 4 and 10 per 1,000) of every human population.  It has occurred in every culture throughout history.  It is most easily recognized in its convulsive form, in which people suddenly fall to the ground, lose consciousness, and writhe with seizures. 

In ancient Greece, it was called the "sacred disease" because it appeared to be caused by divine inspiration.  Around 400 BC, Hippocrates (or someone belonging to the Hippocratic school of medicine) wrote "On the Sacred Disease," in which he began by dismissing the popular belief in epilepsy's divine origin: "The disease called sacred . . . appears to me no more sacred than other diseases, but has a natural cause from which it originates, like other affections."  And, in particular, epilepsy is caused by the brain: "Men ought to know that from nothing else but the brain come joys, delights, laughter and sports, and sorrows, griefs, despondency, and lamentations."

Since the end of the nineteenth century, neurologists have understood that epilepsy is caused by sudden, abnormal electrical discharges in the cortex of the brain (Sacks 2012).  In generalized seizures, the electrical discharge comes from both hemispheres of the brain simultaneously.  In a grand mal seizure, the person falls to the ground with convulsive twitching of the muscles and loses consciousness within seconds.  In a petit mal seizure, a person loses consciousness for only a few seconds without realizing what has happened.  And even the people around him might not notice anything unusual, as they continue talking with him.

In contrast to such generalized seizures, partial or focal epilepsy arises from a particular area of brain damage or sensitivity that can be genetically inherited or acquired by injury.  Focal conscious seizures are often called "auras," which are sometimes warnings that convulsive seizures with loss of consciousness will soon follow.  During an aura, depending on the location of the seizure in the brain, there will be different kinds of sensory or psychic hallucinations.  So, for example, a seizure in the olfactory area of the brain might produce strange smells, or a seizure in the visual cortex might produce visual hallucinations.

"The symptoms of partial seizures depend on the location of the focus:  they may be motor (twitching of certain muscles), autonomic (nausea, a rising feeling in the stomach, etc.), sensory (abnormalities or hallucinations of sight, sound, smell, or other sensations), or psychic (sudden feelings of joy or fear without apparent cause, deja vu or jamais vu, or sudden, often unusual, trains of thought).  Partial seizure activity may be confined to the epileptic focus, or it may spread to other areas of the brain, and occasionally it leads to a generalized convulsion" (Sacks 2012: 134).

What are here identified as "hallucinations" need to be distinguished from illusions and delusions.  In his Principles of Psychology, James explained:

"Hallucinations usually appear abruptly and have the character of being forced upon the subject. . . .They are often talked of as mental images projected outwards by mistake.  But where a hallucination is complete, it is much more than a mental image.  A hallucination is a strictly sensational form of consciousness, as good and true a sensation as if there were a real object there.  The object happens not to be there, that is all" (James 1983: 758-59). 

In ecstatic temporal lobe epilepsy, the hallucinations are mystical experiences of ecstatic or transcendent joy or heavenly bliss, with a feeling of certainty or clarity in the revelation of divine truth (Picard 2023).  For example, one of the first clear reports of ecstatic epilepsy came from Fyodor Dostoevsky, who described his epileptic seizures in his letters and notebooks, and then he described characters in five of his novels as having similar experiences--such as Prince Myshkin in The Idiot (Voskuil 2013).  On one evening before Easter, Dostoevsky was talking with friends about religion.  Then, when a bell tolled midnight, he shouted, "God exists, He exists."  Later, he described his experience in a letter:

"The air was filled with a big noise, and I tried to move.  I felt the heaven was going down to earth, and that it had engulfed me.  I have really touched God.  He came into me, yes God exists, I cried, and I don't remember anything else.  You all, healthy people, can't imagine the happiness which we epileptics feel during the second or so before our fit. . . . I don't know if this felicity lasts for seconds, hours, or months, but believe me, for all the joys that life may bring, I would not exchange this one.

We might assume that people who are already predisposed to religious belief are most likely to have religious seizures.  But doctors who study ecstatic epilepsy have reported some cases of people with no religious belief having a religious conversion as a result their mystical seizures.  Kenneth Dewhurst and A. W. Beard (1970) provided some examples of this.  One was a bus conductor who had an ecstatic seizure while collecting fares:

"He was suddenly overcome with a feeling of bliss.  He felt he was literally in Heaven.  He collected the fares correctly, telling his passengers at the same time how pleased he was to be in Heaven. . . . He remained in this state of exaltation, hearing divine and angelic voices, for two days.  Afterwards he was able to recall these experiences, and he continued to believe in their validity."

But then, three years later, after three seizures over three days, he said that his mind had "cleared," and he had lost his faith.  His religious conversion had been overturned, and he had been converted to atheism!   One of Fabienne Picard's epileptic patients was an atheist physicist who became a Christian after having experienced ecstatic seizures.  Oddly, then, these ecstatic conversions can go from atheism to religion or from religion to atheism.

Gschwind and Picard (2016) surveyed 52 cases of epileptic patients who had had ecstatic auras.  Some of the most common descriptions of what the patients reported included:  ineffable joy, extreme happiness as if one being in Heaven, feeling union with the whole world and with god, feeling like an orgasm, bright and expanding light, complete mental clarity, everything is joined together in one whole, certainty immune to rational doubt, and intense feelings of bliss and well-being.


In 2009, Picard and A. D. (Bud) Craig proposed the hypothesis that the primary brain structure involved in ecstatic epilepsy was the anterior insula deep in the temporal lobe.

I have written previously about Craig's studies of the insula.  He has shown that the insular cortex is a crucial part of the neural network of the brain that supports interoceptive self-awareness and self-ownership of one's body and the social emotions in which concern for oneself is extended to concern for others.  In understanding this, social neuroscience provides the evolved biological ground in the brain for what John Locke identified as human self-ownership or self-concern that is extended to concern for others in mammalian animals like humans.  The Lockean natural right to property is rooted in this natural sense of self-ownership.

The most dramatic evidence for the anterior insula hypothesis to explain ecstatic epilepsy has come from Picard's treatment of epileptics at the University Hospitals of Geneva, Switzerland (Picard 2023).  Working with a patient with ecstatic epilepsy, who was undergoing presurgical evaluation with intracerebral electrodes, she recorded spontaneous seizures that were associated with electrical discharges in the anterior insula.  Moreover, her ecstatic auras could be reproduced through electrical stimulation of her anterior insula.  Even more amazing than that, Picard found that she could induce ecstatic auras by the electrical stimulation of the anterior insula in one patient with temporal lobe epilepsy who had never had ecstatic experiences previously!

If we're persuaded by this evidence that ecstatic epilepsy is somehow connected to the anterior insula, then the next question would be how to explain this:  What exactly is happening in the anterior insula to cause ecstatic seizures?  Picard's primary hypothesis for answering this question proposes "that temporary disruptions to activity in the anterior insula could interrupt the generation of interoceptive prediction errors, and cause one to experience the absence of uncertainty, and thereby, a sense of bliss," because this would "mimic perfect prediction of the body's physiological state" (Picard 2023: 1372).

Craig has claimed that the posterior insula is the primary place in the brain for the representation of interoceptive signals--the signals of the internal physiological state of the body--and integrating those signals with signals from the external environment.  The signals are combined with information from limbic and frontal cortices, and then they are represented as consciously experienced feelings in the anterior part of the insula.

Picard has extended Craig's theory through the theory of predictive coding that has become popular with many neuroscientists (Clark 2023).  The idea of predictive coding is that rather than passively perceiving reality, our mind actively predicts it.  Before our brain receives external signals from our environment and internal signals from our body, our brain has already made top-down predictions about what those signals are likely to be; and then when the real bottom-up signals arrive in the brain, they are compared with the prediction.  The mismatch between the prediction and the real incoming signals provides a prediction error, which can then be used to change the future prediction.

Picard's theory is that an epileptic seizure in the anterior insula can interrupt the predictive coding system, so that a person in the ecstatic state will feel the internal state of his body and the external state of his environment as if he had predicted them perfectly.  This would create a sense of clarity, certainty, and unity with everything in the world, resulting in a feeling of perfect, even heavenly, bliss.

Even if this theory proves not to be completely correct, it does look like the kind of theory that would explain how an epileptic seizure in the anterior insula could produce an experience of mystical ecstasy in contact with the divine.

Of course, this does not mean that ecstatic epilepsy is the only source in the brain for religious experience.  There are other ways in which the brain might facilitate human access to the divine (Nelson 2011; Newberg 2018).


Does this mystical experience affirm the reality of the supernatural realm that fulfills our deepest longings for eternal happiness?  Some of us will say no, because, as James said, it's a hallucination--"a strictly sensational form of consciousness, as good and true a sensation as if there were a real object there," but "the object happens not to be there, that is all."  Others will say yes, because, as C. S. Lewis said, the natural desire for Joy manifest in mystical experience is a sign of the real existence of the object that would satisfy that desire.  I see no way to prove which answer is correct.

Even if we are convinced by a neurological explanation of how mystical experiences arise in the brain, that does not prove that those experiences are pure hallucinations.  After all, God could be using the neural apparatus of the brain as a medium for revealing His truth--a natural cause for a supernatural Revelation.

Something like this might have been intimated by Hippocrates at the beginning of "On the Sacred Disease" when he said that epilepsy was "no more divine than other diseases" that have natural causes.  At the end of his essay, he declared:

"The disease called the Sacred arises from causes as the others, namely, those things which enter and quit the body, such as cold, the sun, and the winds, which are ever changing and are never at rest.  And these things are divine, so that there is no necessity for making a distinction, and holding this disease to be more divine than the others, but all are divine, and all human."

In my next post, I will consider the case of St. Paul.  His mystical vision on the road to Damascus might have been caused by an ecstatic epileptic seizure.  But it's not clear to me that that would deny the possibility that it was also a revelation from God.


Clark, Andy.  2023.  The Experience Machine: How Our Minds Predict and Shape Reality. New York: Pantheon Books.

Dewhurst, Kenneth, and A. W. Beard.  1970.  "Sudden Religious Conversions in Temporal Lobe Epilepsy."  British Journal of Psychiatry 117: 497-507.

Gschwind, Markus, and Fabrienne Picard.  2016.  "Ecstatic Epileptic Seizures: A Glimpse into the Multiple Roles of the Insula."  Frontiers in Behavioral Neuroscience 10:21.

James, William.  1983.  Principles of Psychology.  Cambridge, MA: Harvard University Press.

James, William.  1987.  The Varieties of Religious Experience.  In Writings 1902-1910, 1-477.  New York: The Library of America.

Nelson, Kevin.  2011.  The Spiritual Doorway in the Brain: A Neurologist's Search for the God Experience.  New York: Dutton.

Newberg, Andrew.  2018.  Neurotheology: How Science Can Enlighten Us About Spirituality. New York: Columbia University Press.

Picard, Fabienne.  2023.  "Ecstatic or Mystical Experience Through Epilepsy."  Journal of Cognitive Neuroscience 35 (9): 1372-1381.

Picard, Fabienne, and A. D. Craig.  2009.  "Ecstatic Epileptic Seizures: A Potential Window on the Neural Basis for Human Self-Awareness."  Epilepsy and Behavior 16: 539-546.

Sacks, Oliver.  2012.  Hallucinations.  New York: Random House.

Voskuil, Piet H. A.  2013.  "Epilepsy in Dostoevsky's Novel."  Frontiers in Neurology and Neuroscience 31: 195-214.

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