I’m as sworn to radical rationalism as the next neo-Darwinian materialist. That said, over the years I’ve had to “quarantine,” for lack of a better word, a few anomalous personal experiences that have stubbornly defied my own logical understanding of them.

Once, for instance, I was staying at a hotel in Fort Lauderdale when I had a vivid dream in which there was a knock at the door. I opened it to find my mother’s good friend, Sally, trembling and distraught. “It’s Blaze,” she said to me, weeping inconsolably about her golden retriever. “I can’t find him. He’s not here.” It was such an odd dream that I even shared it with my father the next morning over breakfast. “Weird,” he said, shrugging his shoulders. Later that day at my mom’s house, the phone rang. It was Sally. “It’s Blaze,” she said immediately, sobbing into the phone. “We put him to sleep this morning. I keep expecting him to be in the house but he’s not here, Jesse.”

I can live with the uncertainty surrounding these very few incidents without getting all … unscientific. “Think of all the dreams you’ve had that haven’t come true,” I can tell myself. “So you get one that seems like a premonition. Big deal.” In any event, none of these events have been particularly meaningful to me, just minor hiccups in a naturally ordered universe.

Except for one. Possibly. When my mother died in early 2000, we had a final farewell that some researchers might consider paranormal. At the time, it did strike me as remarkable—and after all these years, I still can’t talk about it without getting emotional. The night before she died at the age of 54 (after a long battle with ovarian cancer), I was sleeping in my mother’s bedroom alongside her. The truth was that I’d already grieved her loss a few days earlier, from the moment she lapsed into what the Hospice nurses had assured us was an irretrievable coma. So at this point, waiting for her body to expire as a physical machine wasn’t as difficult as the loss of “her” beforehand, which is when I’d completely broken down. It had all happened so quickly and, I suppose being young and in denial about how imminent her death really was, I hadn’t actually gotten around to telling her how very grateful I was to have had her as my mom and how much I loved her. But then, around 3am, I awoke to find her reaching her hand out to me, and she seemed very much aware. She was too weak to talk but her eyes communicated all. We spent about five minutes holding hands: me sobbing, kissing her cheeks, telling her everything I’d meant to say before but hadn't. Soon she closed her eyes again, this time for good. She died the next day.

I didn’t quite see the experience as “supernatural” when it happened. And I'm not sure I do today either. But I also didn’t have a name for the experience then. In fact, one didn’t even exist. It does now: terminal lucidity.

Let’s have a more detailed look at the phenomenon in question. The term was coined only five years ago by German biologist Michael Nahm. His 2009 article in The Journal of Near-Death Studies was the first modern review article on the curious subject of cognitively impaired people becoming clearheaded as their death approaches. According to him, cases of “terminal lucidity” had been recorded for millennia, from accounts by classical scholars such as Hippocrates, Cicero and Plutarch to 19th-century medical luminaries like Benjamin Rush (who wrote the first American treatise on mental illness). It’s just that, apparently, no one had thought to label or conceptualize these elusive incidents in any formal way before.

Here’s how Nahm defined terminal lucidity in that original article:

The (re-)emergence of normal or unusually enhanced mental abilities in dull, unconscious, or mentally ill patients shortly before death, including considerable elevation of mood and spiritual affectation, or the ability to speak in a previously unusual spiritualized and elated manner.

The author characterizes terminal lucidity as one of the more common, but lesser known, ELEs (or “end-of-life experiences”). Others on his list include deathbed visions, apparitions, near-death/out-of-body experiences, telepathic impressions, and so on.

But terminal lucidity is a vague concept, needless to say. First of all, what exactly should qualify as the time period “shortly before death”: minutes, hours, days … months? In a follow-up article by Nahm appearing that same year in The Journal of Nervous and Mental Disease, and coauthored with the psychiatrist Bruce Greyson of the University of Virginia, we get some clarification on this. Of 49 case studies of terminal lucidity, the vast majority (84 percent) occurred within a week of death; 43 percent, in fact, transpired the final day of life.

They divide the phenomenon into two general classes, however. In the first subtype, “the severity of mental derangement improve[s] slowly in conjunction with the decline of bodily vitality.” This occurs in some patients with chronic mental illness when their psychiatric symptoms become less pronounced, or disappear altogether, starting around a month before their deaths. Thus, the lucid periods emerge gradually, like clouds parting. The authors offer three Russian case studies from the 1970s as examples, all schizophrenic patients “without prior lucid intervals, living in seemingly stable psychotic mental states for many years.” One man who’d been completely catatonic for nearly two decades allegedly “became almost normal” before he finally passed away.

In the second subtype of terminal lucidity, the authors tell us, “full mental clarity can appear quite abruptly and unexpectedly just hours or days before death.” In one study, 70 percent of caretakers in a British nursing home said they’d personally observed people with dementia becoming lucid shortly before their deaths. (That figure sounded far more impressive to me before I realized there were only 10 respondents.) A 92-year-old woman with advanced Alzheimer’s disease, for instance, hadn’t recognized her family for years, but the day before her death, she had a pleasantly bright conversation with them, recalling everyone’s name. She was even aware of her own age and where she’d been living all this time. “Such incidents happen regularly,” write Nahm and Greyson.

In another example of this second, more abrupt subtype, earlier this year the authors detailed the extraordinary case of a young German woman named Anna (“Käthe”) Katharina Ehmer, who died in 1922. Her case is especially valuable, according to them, because it was witnessed by two highly respected and influential local figures: Wilhem Wittneben, the chief physician at what was then one of the largest insane asylums in Germany (Hephata), and Friedrich Happich, the director of that same institution. Over the years, both Wittneben and Happich relayed the experience many times in speeches and writings, and their independent descriptions of the incident cross-verified each other.

Käthe was among the most profoundly disabled of the patients at the asylum. Happich paints a vivid picture of her mental status. “From birth on,” he writes, “she was seriously retarded. She had never learned to speak a single word. She stared for hours on a particular spot, then fidgeted for hours without a break. She gorged her food, fouled herself day and night, uttered an animal-like sound, and slept … never [taking] notice of her environment even for a second.” As if that weren’t enough, Käthe suffered several severe meningitis infections over the years that had damaged her cortical brain tissue.

Yet, despite all this, as the woman lay dying (shortly after having her leg amputated from osseous tuberculosis—talk about bad luck), Wittneben, Happich, and other staff members at the facility gathered in astonishment at her bedside. “Käthe,” wrote Happich, “who had never spoken a single word, being entirely mentally disabled from birth on, sang dying songs to herself. Specifically, she sang over and over again, ‘Where does the soul find its home, its peace? Peace, peace, heavenly peace!’” For half an hour she sang. Her face, up to then so stultified, was transfigured and spiritualized. Then, she quietly passed away.”

The religious undertones make my eyebrows rise in spontaneous cynicism, but at face value, one has to admit that the story of Käthe Ehmer is something of a puzzle. And in their extensive literature review on the subject—not an easy task, given that “terminal lucidity” couldn’t be used as a search term prior to that first 2009 article—Nahm and Greyson found a total of 81 references to similar cases, reported by 51 different authors. Nineteenth century physicians and psychiatrists, they point out, wrote most of these accounts. By the 20th century, they speculate, doctors simply stopped reporting these incidents altogether because they failed to jive with contemporary scientific materialism.

Yet, even if terminal lucidity is a genuine phenomenon, who’s to say there isn’t a logical scientific explanation, one involving some unknown brain physiology? Nahm and Greyson don’t discount this possibility entirely, but for cases involving obvious brain damage (such as strokes, tumors, advanced Alzheimer’s disease) that should render the patient all but vegetative, not functioning normally, it’s a genuine medical mystery. According to the authors, terminal lucidity also isn’t all just in the perceiver’s head. Rather, they write, “it seems to be more common than usually assumed, and reflects more than just a collection of anecdotes that on closer scrutiny emerge as wishful thinking.” This then, to them, leaves open the possibility of something more spiritually significant, with the “transcendantal subject” (i.e., the soul) loosening itself from the physical substrate of the brain as death approaches and being able to enter “usually hidden realms.”

I remain a skeptic. Still, I really don’t know how my mother managed those five minutes of perfect communion with me when, ostensibly, all of her cognitive functions were already lost. Was it her immortal soul? One last firestorm in her dying brain?

Honestly, I’m just glad it happened.