"For me it's mystical, and seems an intriguing starting point to study the process of memory storage."įor decades, researchers have believed that deja vu is usually a false memory-a kind of sleight of hand of the brain by which a few familiar features trick us into thinking we are reliving a past experience.
"Everyone tends to associate this with the question of has there been a previous life," he says. Meanwhile, Sno is planning a study using firsthand accounts of deja vu experiences.
The theory will have to be proved by more than analogy, of course. By putting the two side by side, first in a scrambled form, then gradually bringing them into sharper focus that reveals them to be two different people, Sno was able to provide an arresting photographic analogy of deja vu. Sno says he found a way to illustrate that hypothesis when he saw a picture of Abraham Lincoln in a Dutch newspaper that reminded him of a photo of Sigmund Freud. However, say the two psychiatrists, what happens in deja vu is that while clusters of holographic data may comprise totally different memories, portions of them may be identical, momentarily fooling us into thinking we are re-experiencing something. The implication is that, just as in a hologram, there is enough information tucked into any one cluster of brain cells to evoke an entire memory. As a model for brain function, it helps explain how memories can be revived by stimulating a section of the brain and, at the same time, why the memory remains even after that section is surgically removed. The holography principle, used in three-dimensional photography, is that any part of a photographic plate has enough information stored in it to reproduce the whole picture. That idea has been around for a while, but Sno and Linszen base their new wrinkle on the theory, put forth in recent years, that memories are stored in the brain in the form of holograms. Herman Sno and Don Linszen contend that deja vu is really a false memory, triggered by a current experience that has some features in common with an earlier one. Writing in the December American Journal of Psychiatry, Drs.
Now a couple of Dutch psychiatrists at the Academic Medical Center in Amsterdam have pitched in yet another, derived from one of the newer-fangled notions about memory itself. South African neuropsychiatrist Vernon Neppe, author of a book on the subject, put the number of existing theories at 44, and has since added one or two more. Explanations to date have included everything from reincarnation, a notion favored by 19th-century Romantic poets, to the modern biological view that it is a disturbance of the temporal lobe of the brain. While descriptions of the deja vu experience go back at least as far as Saint Augustine, nobody yet has come up with a definitive theory of what causes it. Intrigued by the mystery, he had begun compiling literary references to the subject when he was in high school, wrote his senior thesis on it in medical school and then became a dermatologist-leaving the solution to others.īut Kohn can take heart. There was one more coincidence that the young man wasn't aware of Kohn happened to be something of an authority on the phenomenon of the "already seen"-better known as deja vu. He was "overwhelmed" by the feeling that some time in the past "he had stood on just such a street and had gazed at just such an arrangement of tweed suits and striped shirts." More than that, there were the same weather, the same traffic noise and an uncanny foreknowledge that a stranger like Kohn would engage him in just the sort of conversation they were having. As Kohn recounted the incident in the Journal of the Medical Society of New Jersey, the young man explained in an awe-struck voice that although this was his first trip to New York, everything seemed eerily familiar. Steven Kohn noticed an apparently bewildered young tourist standing in front of a haberdasher's shop. Walking in Manhattan's Greenwich Village one drizzly morning, Dr.