Sometimes we think we knew what was about to happen. Mystically minded people tend to see this as a gift of divination. But maybe the science is right and it’s just a cognitive illusion?
For many, déjà vu is just a fleeting, creepy “I’ve been here before” feeling. However, for some, this becomes a real mystical experience: they seemed to know what would happen next: for example, that a girl in a white shirt would pass from the left. How to explain it? Should we look for signs of the supernatural in these phenomena – for example, clues about past lives?
Don’t jump to conclusions like that, says Ann Cleary, a memory researcher at Colorado State University. Ann is one of the world’s deja vu experts. Using laboratory experiments to induce and then explore this state in test subjects, she theorized why it is accompanied by a feeling of “I knew this would happen.”
Premonitions in hindsight
The Cleary project revealed a strong bias in people experiencing deja vu in everyday life: they supposedly knew what would happen next. But in the laboratory, their predictions do not come true, so this is nothing more than a feeling, and a deceptive one at that. “If this illusion is just a feeling, why do people believe so much that they actually predict what will happen next? Maybe it’s a cognitive illusion.”
To test this theory in the lab, Cleary and her colleagues placed a control group in a setting very similar to the famous Sims video game. Participants were asked if they experienced deja vu. Then the virtual scene turned left or right, and the subjects were again asked if they guessed which way it would turn. In a later experiment, participants were asked to rate whether the scene itself was familiar to them, both before and after the turn.
After summarizing the results, the scientists found that when déjà vu was accompanied by strong feelings of prediction, it correlated with what we would call “experiencing in hindsight.” That is, after the fact that the scenery turned, the person reported that he knew what kind of turn was supposed to happen. But the experiment was organized in such a way that people could not know this in any way, since the turns were made completely randomly.
That “I knew this was going to happen” feeling was very strong when the déjà vu was happening, and especially strong when the scene was rated as very familiar by the contestant. It was nothing more and nothing less than a strong bias after the fact.
cognitive illusion
Cleary’s team concluded that the high degree of familiarity that accompanies déjà vu also affects postdictive bias, the one that works “in hindsight.” “If the whole scene after the turn seems very familiar to us, it can make the brain think that we got it right,” comments Ann Cleary. “And because it’s all so familiar, we’re pretty sure we knew what was going to happen.”
Deja vu as a phenomenon of memory
So the “I knew this would happen” belief is part of the prediction illusion that often accompanies deja vu, Cleary says. According to her previous experiments, déjà vu is a memory phenomenon in which we try to recover a fragment of it, but we cannot “catch” it. It is similar to the feeling when the forgotten word “spins on the tongue.” Previous experiments in her lab showed that when subjects were shown in front of Sims scenes they had previously seen but forgotten, more cases of déjà vu occurred.
Since Cleary began studying déjà vu more than a decade ago, many subjects have told her about their experiences of this state, including when they were quite sure they had predicted something. And it’s not that these people believed in the supernatural – many of them were, according to the scientist, skeptics, such as her colleagues, memory researchers.
New research
Cleary’s work continues by joining forces with neuroscientists at Emory University who work with patients diagnosed with medial temporal lobe injuries that cause severe, recurrent déjà vu.
Ann Cleary also organizes experiments in which déjà vu can be experienced through the auditory channels rather than visually. “Déjà entendu” is a phrase used when a person has heard something before but cannot “catch” the memory. This is another side of the question to which Cleary and her students are ready to devote new research.