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This Eerie State of Consciousness Makes Your Brain Feel Broken—but It May Be Keeping You Alive

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That eerie feeling when the world suddenly becomes unfamiliar has a name: jamais vu.
While the phenomenon is relatively mysterious, researchers suggest that it could have a similar purpose to déjà vu, which may be a built-in version of “fact-checking.”
Jamais vu isn’t always a random event, either; studies show that you may be able to intentionally induce it.

On a cloudy, nondescript day, Akira O’Connor was driving along the M1 motorway in England when, suddenly, the controls of his car became totally unfamiliar. He had to consciously think about how to control the car: moving his right hand up and left hand down on the wheel would move it counterclockwise, which in turn would make the car go left. Bewildered, O’Connor pulled over to get his bearings. Within a minute, everything felt normal again, and he was able to drive home safely.

O’Connor, PhD, a psychology professor at the University of St. Andrews in Scotland, had experienced the psychological phenomenon known as jamais vu. Compared to its counterpart, déjà vu, very little is known about these fleeting feelings of unfamiliarity. But recent research has aimed to uncover its roots, leading to speculation that—despite the danger it put O’Connor in—jamais vu could be your brain protecting itself.

While déjà vu occurs when an experience that you know hasn’t happened before feels familiar, jamais vu is the inverse: a disconcerting feeling of unfamiliarity for something that should be known. What distinguishes the phenomenon from a simple memory malfunction is that, ultimately, all of the knowledge is still there. Take a musician who experiences jamais vu while playing a song. They still know how to play the instrument—it’s the sense of familiarity with the process that is lost, making it momentarily feel foreign.

Jamais vu doesn’t strictly occur with routine activities, such as driving or playing music. It can also take place when you encounter previously known faces, places, and even words. However, it appears that the glitch may be more likely to transpire alongside states that diminish your brain’s processing abilities. For instance, fatigue, stress, and certain neurological conditions (particularly temporal lobe epilepsy) all make the list.

But just because jamais vu occurs in a variety of settings doesn't mean it occurs often. Though exact figures vary, researchers agree that healthy individuals are far less likely to experience the phenomenon than déjà vu, which only occurs a couple of times a year itself. That infrequency—in addition to it being a subjective personal experience—makes jamais vu extremely difficult to study in a controlled setting.

However, O’Connor and other researchers solved part of that problem. Led by Chris Moulin, PhD, a cognitive neuropsychology professor at Grenoble Alpes University in France, the team used word alienation tasks to induce jamais vu–like feelings. In one part of the experiment, researchers instructed participants to copy the word “the” 120 times and pause at any point if the word felt peculiar. Fifty-five percent stopped before completing the task fully, reporting a variety of strange sensations the researchers defined as jamais vu.

The researchers also hypothesized that the rate of jamais vu–like feelings depended on the word’s frequency of use in everyday life—the idea being that common words are more likely to generate the disconnect present in jamais vu, as they already have familiarity established. The results supported their idea, as trials with high-familiarity words (like “door” and “money”) caused higher rates of jamais vu than those with low-familiarity words (like “sward” and “usury”).

In an article for The Conversation, Moulin and O’Connor explained how their findings support the idea that jamais vu signals when something has become too fluent, helping people snap out of that repetitive processing. “It makes sense that this has to happen,” they wrote. “Our cognitive systems must stay flexible, allowing us to direct our attention to wherever is needed rather than getting lost in repetitive tasks for too long.”

The researchers’ conclusion mirrors a popular theory that characterizes déjà vu as an evolutionary adaptation. With the dissonance between familiarity and actual experience, déjà vu helps the brain become aware that there’s a mismatch in memory, acting almost like a fact-checking process. Could detecting the inverse problem—that is, a known setting seeming unfamiliar—through jamais vu mean it’s a biological safety net as well?

O’Connor thinks it’s an intuitive conclusion to arrive at, especially in the context of doing something repeatedly: “In a kind of evolutionary sort of way, it does make sense to say that’s a stop mechanism in your brain.” However, he notes the use of the term “evolutionary” is intentionally provocative, and there’s currently no concrete evidence to support or refute the claim.

Moulin follows the same line of thought. “It could be a byproduct of how we’re hardwired,” he says. “[But] the fact that it doesn’t happen much makes me think that it might just be a meaningless glitch.”

Before researchers uncover the theoretical purpose of jamais vu, Moulin says they still need to accomplish the basics—like what jamais vu even looks like to begin with. “That would be the best thing—just simply that we can measure something that’s different in the brain of somebody who says they’re having jamais vu,” he says. “There’s a whole bunch of related phenomena, and it would be nice to know if they are all the same thing.”

Despite this uncertainty, there are already hints as to what regions of the brain might be involved with jamais vu. The phenomenon’s high occurrence in patients with temporal lobe epilepsy—a condition involving seizures in the brain’s temporal lobe, an area associated with memory processing—suggests its physiological roots lie in that region. And a study published in Nature Neuroscience in 2017 identified potential pathways within this area for these errors to occur. Researchers from the University of Massachusetts Medical School found evidence that the interpeduncular nucleus (IPN), a group of neurons in the midbrain, controls familiarity signaling—judgment of whether an experience is brand-new or familiar. Their experiments with mice found evidence the IPN balances its judgments based on input from two other areas within the midbrain: The ventral tegmental area signals whether or not an experience is novel, while the medial habenula relays information on its familiarity.

These independent, yet overlapping patterns could be key to explaining where the disconnect between novelty and familiarity occurs with jamais vu. But that requires further study—research that Moulin believes has great potential, regardless of outcome. “You can see the building blocks for lots of interesting metacognitive subjective experiences by studying that kind of thing,” he says. “Even if it is just a weird quirk, it’s a weird quirk that tells us something about how the mind operates.”

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This Eerie State of Consciousness Makes Your Brain Feel Broken—but It May Be Keeping You Alive

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