In French, déjà vu literally translates to “already seen”, and describes the phenomenon of having the strong feeling that the experience you’re having right now has already been experienced by you in the past. It’s clearly not a glitch in the Matrix, but scientists have been struggling for centuries to explain what prompts a feeling of déjà vu – and why. But now a team of neuroscientists just might have an answer.
Led by Akira O’Connor from the University of St Andrews in the UK, the team figured out how to trigger a feeling of déjà vu in a lab setting – making something that’s spontaneous, fleeting, and unpredictable a little bit easier to nail down. They did this by slightly tweaking a neat trick used by neuroscientists to implant false memories in the minds of their participants.As Jessica Hamzelou explains for New Scientist, this involves reciting a list of related words, such as bed, pillow, night, and dream, but deliberately leaving out the single, most obvious word that links them all – in this case, sleep.
The participants are later asked about all the words they were told, and more often than not, will swear they heard “sleep”, along with the others. So that’s how you implant a false memory, but it’s not quite the same thing as déjà vu. So O’Connor and his team added a step. In the first part of the experiment, where the participants were hearing the related words, the researchers asked them if they’d heard a word starting with “S”. Of course, they hadn’t, so the participants replied “No.” Later, when the participants were asked to recall all the words they’d heard, they knew from earlier that they hadn’t heard a word starting with “S”, but at the same time, the false memory of sleep had been implanted, so it somehow felt familiar.
“They report having this strange experience of déjà vu,” O’Connor told Hamzelou.Trying this technique out on 21 participants, the researchers observed what was happening in their brains as they experienced the feeling of déjà vu.Interestingly, even though the technique involved a memory exercise and the participants were given a false memory, the parts of the brain related to memory weren’t the ones that lit up in the fMRI scans.
At the International Conference on Memory in Budapest, Hungary, last month, O’Connor told his peers that during the experience of déjà vu, frontal areas of the brain associated with decision-making were activated. Source: This new study might actually explain the weirdness that is déjà vu