That odd moment when you walk into a place & swear you’ve been there, even though you know you haven’t, isn’t just you. Scientists have studied déjà vu for years through some unusual experiments. It turns out that the brain has a lot of ways of tricking itself. Here are six interesting things scientists have actually found. Which one do you think is the strangest?
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Electrical stimulation in the temporal lobe can trigger déjà vu
Doctors discovered in neurosurgery labs that zapping certain parts of the brain can set off instant déjà vu. Patients reported feeling as though they were somewhere familiar or even that they had dream-like memories when the electrodes hit the temporal lobe. This is also true in epilepsy cases. Some people feel a sense of déjà vu right before a seizure.
People experience less déjà vu when they’re older
Questionnaires & surveys show déjà vu changes as you age. Teenagers & young adults say they get it a lot, but older adults report it far less, which could be due to stress and fatigue. In fact, one study estimated that around 60% of people have experienced déjà vu at least once. But how often that happens depends quite a lot on your age.
Your brain’s right-side experiences it more
Neurologists compared left vs. right brain stimulation and found something interesting. Déjà vu shows up a lot more often on the right. Patients with epilepsy had electrodes placed in both sides of the temporal lobe, and they reported stronger déjà vu when the right side was activated. That makes sense, since it’s where your hippocampus & rhinal cortex work together.
Some people suffer from “déjà vécu”
Experiencing déjà vu just once can be strange. Now imagine feeling it all the time. For some people, that’s a reality. They feel as though every single thing they do has already happened before. It happened to at least two dementia patients in an experiment, as well as someone with anxiety. Doctors called this “déjà vécu.” It means “already lived.”
Hypnosis can create déjà vu
In 2009, a group of researchers used hypnosis to see how it would affect people’s sense of déjà vu. Participants were told under hypnosis that certain new words would feel familiar later on. When those words actually appeared, the volunteers swore they’d seen them before. But they hadn’t. Clearly, hypnosis can make your brain play all sorts of tricks on you.
Some amnesia patients still experience déjà vu
Even memory loss can’t block déjà vu completely. In one case study, patients with serious amnesia (aka people who couldn’t recall events from just minutes before) still claimed to have feelings of déjà vu. The research found this could be connected to damage in the temporal lobe.
The following sources were consulted in the preparation of this article:
- The dreamy state: hallucinations of autobiographic memory evoked by temporal lobe stimulations and seizures
- Validation Study of Italian Version of Inventory for Déjà Vu Experiences Assessment (I-IDEA): A Screening Tool to Detect Déjà Vu Phenomenon in Italian Healthy Individuals
- Memory scrutinized through electrical brain stimulation: A review of 80 years of experiential phenomena
- Disordered memory awareness: recollective confabulation in two cases of persistent déjà vecu
- Déjà Vu in the Laboratory: A Behavioral and Experiential Comparison of Posthypnotic Amnesia and Posthypnotic Familiarity
- Déjà Experiences in Temporal Lobe Epilepsy
