Science Studies Deja Vu

By Zach Schepis

Photo courtesy of frankieleon.

A man walks into a memory clinic.

No, this is not the setup to a cheap joke told from the comfort of a bar stool. Stay prescient; try to remember.

He is joined by his wife. Together they enter the pale fluorescent glow of the observation room. A psychologist is waiting to test the man’s ability of recollection.

Something isn’t quite right. Although the patient has never been here, he claims exactly the opposite. His tone gradually becomes more and more insistent. Surely he has been to this exact same room, seen this exact same doctor before. He knows his memory has already been tested.

His wife snaps.

“There you have it!” she exclaims, bordering on manic exhaustion. “You have permanent deja vu.”

Observing this bizarre scene unravel from the other room is Chris Moulin. At this point in time Moulin is quite young, not yet the esteemed cognitive neuropsychologist who will later go on to study at England’s Leeds University and France in the years ahead.

No, here he’s an employee of the memory clinic. Yet this unusual interaction has piqued an irreversible spark in the budding psychologist’s imagination. Later that night he returns home to research the phenomenon we commonly refer to as deja vu (the French term for “already seen”).

Much to his chagrin, Moulin’s inquiries yield few insights into the condition.

“I was very surprised to discover there was so little available on the subject,” Moulin tells BTR. “That one particular case I observed, that’s really what got me started in this field.”

Most have experienced the odd sensation at some point. In fact, more than half of all individuals between the ages of 15 and 25 will eventually have an encounter with deja vu. Yet reliving the fleeting feeling on more than a daily basis is extremely rare. It’s the stuff of nightmares.

Scientists call it recollective confabulation. It’s fancy jargon that equates to what Moulin refers to as an “honest form of lying.” The memory becomes so confused that it begins to fabricate false recollection of events. Sometimes even the recollection of recollecting can be triggered, casting a chiaroscuro of uneven memories bathed in both darkness and light.

So how rare is this condition? Extremely. It took Moulin and his team of researchers more than a decade to find 13 people suffering from it. To be fair, this kind of study isn’t exactly popular in the scientific community.

“There’s not many other people in the world working on this,” admits Moulin. “I probably get one or two emails a month, predominately from people in English-speaking countries. I’d say there’s probably only 20 people experiencing this condition right now in the world.”

That being said, assembling 13 of these individuals in the same room offered invaluable consolation that they weren’t completely mad, that there were others out there just like them.

In the beginning, several common threads began to emerge. Most of the patients were much older–in their mid to late 70s. Throughout their lives, damage to the memory banks of the brain or subsequent cell-loss in those regions proved to be potential catalysts. Other cases involving younger individuals linked epilepsy as a predominant cause.

Photo courtesy of Wikimedia Commons.

“Deja vu has only started to be taken seriously as a field of scientific study over the past 10 years,” says Moulin. “It was considered to be ‘too mystical’ before then. However it was 19th century European neurologists who first noticed that patients would undergo strange mental states of awareness before fits of epilepsy.”

While there is still no proven theory to explain exactly why deja vu occurs in epileptics or healthy people, scientists have pinpointed the temporal lobe of the brain as the seat where it occurs. In fact, sending electrical currents through this region can even induce the phenomenon (don’t try this at home!).

Imagine the temporal lobe is a loaded gun. For the majority of the population, this gun will misfire from time to time. But for epileptics suffering from recollective confabulation, this gun misfires permanently.

In most cases, those who suffer from this persistent deja vu aren’t aware that it’s occurring. There are always exceptions, however, and the rabbit hole seems to have a way of going just a bit deeper.

It’s a case that publications are heralding as one of the strangest instances of deja vu ever recorded in medical history. A 23-year-old British man has been living with a persistent case of the phenomenon for more than eight years now.

To Moulin, individuals like this are an anomaly inside an anomaly. They don’t fit the old age bracket, haven’t sustained brain damage or trauma, and aren’t epileptics. To make matters even stranger, they’re aware that they have a memory condition, yet can’t seem to break it.

“Their kind of category is unknown, their diagnosis is unknown,” admits Moulin. “It’s quite depressing for them; they can’t even turn on the television, read the paper, or sometimes even leave their apartment because they feel as though they’ve already done it all before.”

It’s this third, unexplainable category of patients that Moulin has been working with most recently. A variety of techniques have been employed to break the endless cycle of falsified recognition, however none have been successful as of yet.

In one instance an individual was shown a film he had never seen before. Seconds into the movie he would immediately lose interest, even become sad, announcing that he’d seen it before and no longer wanted to watch it.

However, when shown a film he had seen before, but many years ago, the patient would still possess a desire to sit through it–claiming his memory condition prevented him from remembering it in its entirety.

It’s the realization of the memory condition that makes this third group of recollective confabulators particularly hard to treat. In a sense, it’s the perfect answer. It reveals the patient is aware that his or her mind is playing tricks, yet on the other hand the feeling of recognition is so intense that it simply can’t be escaped through logic alone.

“We’re not computers regurgitating information,” says Moulin. “We relive moments and they feel quite real and strong to us. That’s one of the main things I’ve learned from these patients.”