Déjà Vu Finally Recognized as Mainstream Science
Have you ever experienced that strange feeling that you’ve been in a situation exactly like this before, yet can’t recall when? Everything feels hazy, leaving you feeling both unfamiliar and familiar?
Most of us are baffled by the peculiar sense of familiarity when doing something for the first time. We feel that we have been here before or have done this before, but we know it is impossible. In fact, according to several surveys, about two-thirds of us have experienced déjà vu at least once in our lives.
This phenomenon, known as déjà vu, has puzzled philosophers, neuroscientists, and writers for a very long time.
Déjà vu – means “already seen” in French – was coined in 1876 by French philosopher and psychologist Émile Boirac. (Image: Patrick Chauvel, MD / Health.clevelandclinic.org)
Starting from the late 1800s, many theories began to emerge regarding what might cause déjà vu, [the term means “already seen” in French].
People speculated that déjà vu might arise from a mental dysfunction or perhaps a form of brain issue. Or it could be a temporary glitch in the normal functioning of human memory.
Déjà Vu: From Mystique to Mainstream Science
At the beginning of this century, a scientist named Alan Brown – PhD, Professor of Psychiatry and Epidemiology at Columbia University Medical Center (USA), and author of many books on déjà vu – decided to review all that researchers had written about déjà vu up to that point.
Alan Brown – PhD, Professor of Psychiatry and Epidemiology at Columbia University Medical Center (USA), author of many books on déjà vu. (Image: Columbiapsychiatry)
Specifically, in 2003, Alan Brown published a paper in the Psychological Bulletin reviewing lesser-known aspects of déjà vu and connecting that information with existing models in cognitive psychology and memory research. Essentially, his groundwork laid the foundation for the research community to gain a deeper insight into this phenomenon in the years to follow. Since then, he and several scientists have brought the study of déjà vu into mainstream science.
Much of what he found had an air of mystique, linked to the supernatural—concepts like past lives or psychic abilities.
In addition to these mystical associations, déjà vu presented another hurdle for researchers. This experience typically lasts no more than a few seconds and offers no warning of when it will occur, making it extremely challenging to study. Most of what is known about déjà vu is based on surveys.
From all this research, Alan Brown was able to gather some fundamental findings about the déjà vu phenomenon.
For instance, Alan Brown determined that about two-thirds of people experience déjà vu at some point in their lives. He found that the most common trigger for déjà vu is a scene or location, followed by conversations.
He also reported suggestions over a century or more in medical literature about a possible link between déjà vu and certain types of brain seizure activity.
Alan Brown’s review brought the topic of déjà vu into a more scientific realm, as it appeared in a scientific journal that cognitive researchers tend to read, as well as in a book for scientists. His work acted as a catalyst for scientists to design experiments to investigate déjà vu.
Déjà Vu Experiments in Psychological Laboratories
Driven by Alan Brown’s work, a research team led by Professor of Cognitive Psychology Anne Cleary (from Colorado State University, USA) conducted experiments aimed at testing hypotheses regarding the potential mechanisms of déjà vu.
Professor Cleary’s team investigated a nearly century-old hypothesis suggesting that déjà vu can occur when there is spatial similarity between a current scene and an “unlabeled” scene in your memory. Psychologists refer to this as the Gestalt Familiarity Hypothesis (a school of psychology that emerged in Austria and Germany in the early 20th century).
For example, imagine you are passing by the nursing station in a hospital on your way to visit a sick friend. Although you have never been to this hospital before, you might feel as if you’ve been there.
The underlying cause of this déjà vu experience could be the layout of the scene, including the arrangement of furniture and specific objects in space, resembling a scene you have experienced in the past.
Researchers state that people have experienced this phenomenon long before it was named. (Image: Internet)
The arrangement of the nursing station—furniture, items on the counter, how it connects to the corners of the hallway—might resemble the setup of a welcome desk with signs and furnishings in the hallway at the entrance to a school event you attended a year prior.
According to the Gestalt Familiarity Hypothesis, if the previous situation with a similar layout does not come to mind, you may be left with a strong sense of familiarity regarding the current situation.
To investigate this idea in the lab, the team of scientists used virtual reality to place individuals in specific circumstances. This way, researchers could visualize the environment in which the participants found themselves.
As predicted, déjà vu was more likely to occur when individuals were in a scene with a similar spatial arrangement of elements as a previous scene they had viewed but did not consciously recall.
This study suggests that one contributing factor to déjà vu may be the spatial similarity of a new scene to a scene in memory that is currently not consciously recalled.
However, this does not mean that spatial similarity is the only cause of déjà vu. It is very likely that multiple factors may contribute to making a scene or situation feel familiar. Further research is underway to investigate additional factors that may be involved in this mysterious phenomenon.
The French term déjà vu was coined in 1876 by French philosopher and psychologist Émile Boirac. According to researchers, people have experienced this phenomenon long before it was named.
Over the centuries, people have often regarded déjà vu as evidence of their beliefs. Sigmund Freud viewed déjà vu as repressed desires. Carl Jung suggested that this experience is related to the collective unconscious. Plato described something resembling déjà vu as evidence of past lives. And of course, there is a modern notion embraced by Hollywood that déjà vu is the result of a glitch in the Matrix….
While no one has yet pinpointed the exact cause of déjà vu, it is reassuring that science is finally taking this strange phenomenon seriously.
“I believe that research on déjà vu will shed light on the processes that help us understand memory better at a broader level than just trying to understand déjà vu itself,” says Anne Cleary, Professor of Cognitive Psychology and memory researcher at Colorado State University, USA.
