



Pat's daughter Susan began to scour the Internet, looking for information about her mother's repeated déjà vu episodes. She eventually came across the work of Chris Moulin, a neuropsychologist at Leeds University, in England. Moulin and several colleagues had published two scientific papers describing something they called persistent "déjà vécu" — literally translated, the feeling of having "already lived through" something. The cases seemed to match Pat's condition, and Susan sent Moulin an e-mail message asking for help.

Image Credit... Photomontage by Gerald Slota

Chris Moulin's office is located on the top floor of the psychology department at Leeds, in an oddly asymmetrical brick building at the center of campus. The room is cramped but spare, with a small collection of books in one corner, a pair of soccer cleats stashed under a chair and a set of framed Tintin cartoons on the wall. Moulin is 32 years old, with red, close-cropped hair, a matching beard and glasses and a penchant for jeans and sneakers. Today he's one of only a handful of scientists studying déjà vu-like illusions, but like most of us, he once thought of déjà vu as just an occasional, odd event in his own life. Translated literally from the French as "already seen," déjà vu can be, for some people, a strange and unsettling experience; for others, thrilling or even spiritual. Occurring at seemingly random times, lasting from a few seconds to a few minutes, it often comes with a feeling of approaching premonition. Not only does the situation feel familiar, but a vision of the future also seems just beyond the searchlights of your conscious mind.

The accepted scientific definition of déjà vu, put forth in 1983 by a Seattle-based psychiatrist named Vernon Neppe, is "any subjectively inappropriate impression of familiarity of the present experience with an undefined past." Beyond the definition, however, the scientific understanding of this "inappropriate familiarity" remains murky. Religion and parapsychology have offered their own explanations, citing déjà vu as evidence for everything from clairvoyance to past lives. Because the phenomenon is difficult if not impossible to reproduce in a laboratory, though, researchers like Moulin have traditionally had limited means to dispel the conventional wisdom. At the beginning of his career, he says, "I didn't know anything about déjà vu, and it didn't really interest me."

In December 2000, Moulin was a postdoctoral student in neuroscience at the University of Bristol, working at a memory clinic in a hospital nearby in Bath, when he received a strange referral letter from a local doctor. It described an 80-year-old Polish immigrant whose wife said that he was suffering from "frequent sensations of déjà vu." The doctor had suggested to the man — a former engineer identified by his initials, A.K.P. — that he set up an initial appointment at the memory clinic. A.K.P. responded that he had already gone and didn't see the point of going back. The problem was, as the doctor knew, he hadn't actually ever been there.

Intrigued, Moulin started visiting A.K.P. and his wife at home. "He was very witty and articulate, able to look after himself," Moulin recalls. But A.K.P.'s wife was frustrated by his déjà vu, and he experienced other mental problems, including memory loss and confabulation, the use of subconsciously invented stories to cover memory deficits. His déjà vu episodes seemed to be "practically constant," as Moulin and colleagues outlined in a 2005 paper in the journal Neuropsychologia:

He refused to read the newspaper or watch television because he said he had seen it before. However, A.K.P. remained insightful about his difficulties: when he said he had seen a program before and his wife asked him what happened next, he replied, "How should I know, I have a memory problem!" The sensation. . .was extremely prominent when he went for a walk — A.K.P. complained that it was the same bird in the same tree singing the same song.. . .When shopping, A.K.P. would say that it was unnecessary to purchase certain items, because he had bought the item the day before.

Searching the modern scientific literature, Moulin found one case that echoed A.K.P.'s, that of an 87-year-old woman, who, according to a brief journal article from 2001, "reported that she was continuously reliving the past and felt that a significant part of her daily experiences had happened before." Moulin's mentor, Martin Conway, a pioneer in the understanding of episodic memory, also recalled a paper by the Harvard psychologist Daniel Schacter in the mid-1990's. Schacter had described B.G., a man in his 60's, who claimed to recognize people and situations he'd never encountered.

Those cases persuaded Moulin that A.K.P. was more than an anomaly, and the clinic began sending him any patients with conditions that sounded similar. A month later, a referral letter arrived for M.A., a 70-year-old woman with what the doctor described as pervasive déjà vu. M.A. also found newspapers and television overwhelmingly familiar, and had even quit playing tennis, claiming that she knew the outcome of every rally. Moulin quickly discovered that in contrast to ordinary déjà vu experiences, in which the sensation instantly seems misplaced, neither A.K.P. nor M.A. recognized that something odd was happening. To them, the experiences simply felt like memories. "When we have déjà vu, we don't act on it," Moulin says. "But these people refused to watch television, they stopped reading the newspaper." The patients were what cognitive scientists call "anosagnosic" — unaware of their condition. They also found situations to be more than just familiar; they believed that they were really recalling them, so much so that they invented memories to justify that belief. They were, to use Tulving's phrase, time traveling to a reality that had never existed.