Do you get Déjà Vu?

Audience: Middle School Students

[That strange feeling when you know you’ve seen this before, but you also know you haven’t.] Photo by Buddha Elemental 3D from Unsplash

Introduction: Why Studying Déjà Vu Matters

Have you ever scrolled through your phone, looked at a social media post and thought, “haven’t I already seen this before?” but the post is brand new. That’s some classic déjà vu. Déjà vu is defined as a feeling of having already experienced the present situation. Understanding déjà vu can offer insight into how memory and perception work (since that is what triggers it). It can help scientists explore connections between the conscious and subconscious mind. Studying déjà vu matters because it reveals the complexity of human memory, perception, and how our brains interpret reality.

How the Brain Processes Information and Memory

Short-term memory refers to the brain systems involved in storing information for a short period, usually up to around 30 seconds. An example of this would be  watching a reel, and then forgetting it two minutes later. Long-term memory refers to the brain systems involved in storing events for a long time. For example, you may be able to remember a memorable trip abroad from a couple years ago better than a conversation from four hours ago. The brain regions involved include the temporal lobe, which focuses on memory and recognition, and frontal lobe, which focuses on decision-making and awareness. So how does the brain process information? In the brain, genetically determined circuits are the foundation of the nervous system. Neuronal circuits are formed during embryonic development and modified through interactions with the internal and external environment. Sensory circuits (five senses) bring information to the nervous system. Motor circuits send information to muscles and glands. For the reflex circuit, sensory touch stimulus directly triggers an immediate motor response. When the brain gets a signal from many circuits, a complex response is created by the brain. Déjà vu may occur when your brain experiences a “memory glitch” which is when the brain processes cause memories to misfire or overlap.

Possible Causes of Déjà Vu (Scientific Findings and Studies)

Here are some “memory glitch” scenarios that can cause you to experience déjà vu. First up, the memory mismatch theory: déjà vu occurs when the brain mistakenly perceives a new experience as familiar due to overlapping memory patterns. This is supported by studies on false memories and recognition errors. Next, the dual processing theory is when two cognitive processes (familiarity and recollection) are out of sync, leading to a false sense of recognition. There are also a lot of neurological explanations for déjà vu: Temporal lobe epilepsy is linked to déjà vu, since feelings of déjà vu are often reported before seizures. Scientists are also using brain simulations to further their findings. This includes experiments that artificially trigger déjà vu sensations using brain stimulation or virtual reality.

Common Misconceptions, New Discoveries, and Ongoing Research

Before concluding, it's important to clear up some common misconceptions. Firstly, déjà vu is not a sign of supernatural events, past lives, or psychic ability. Additionally, it’s not necessarily a sign of a brain disorder. Nevertheless, everyone can experience déjà vu and it’s completely normal. Scientists and doctors have been making recent discoveries as well, so the reasoning and findings can change in the future. Some MRI and cognitive studies showing déjà vu correlates with healthy memory functioning. Others suggest it may help detect errors or inconsistencies in memory. Like all STEM puzzles, there is always ongoing research. Scientists keep exploring how sleep, stress, and attention affect déjà vu. Additionally, using AI and virtual simulations to recreate déjà vu in lab settings can be helpful in drawing conclusions and discovering new findings.

Conclusion

In summary, déjà vu is a fascinating glimpse into how our brains process and store experiences. Understanding déjà vu helps unravel the mysteries of memory and perception, which can be quite complex. The next time you feel déjà vu, it may be your brain revealing just how intricate and extraordinary your memory truly is. So ask yourself, do you get déjà vu?

Bibliography

Huizen, Jennifer. “What to Know about Short-Term and Long-Term Memory Loss.” Medicalnewstoday.com, Medical News Today, 29 Oct. 2021, www.medicalnewstoday.com/articles/memory-loss?utm_source=chatgpt.com#memory-loss-causes

‌ The University of Queensland. “Lobes of the Brain.” Queensland Brain Institute, 2018, qbi.uq.edu.au/brain/brain-anatomy/lobes-brain

‌

“How Your Brain Processes Information.” Www.brainfacts.org, www.brainfacts.org/core-concepts/how-your-brain-processes-information

“The Mechanics of Déjà Vu.” Psychology Today, 2025, www.psychologytoday.com/us/blog/common-sense-science/202505/the-mechanics-of-deja-vu

Thompson, Valerie. “Dual Process Theory - an Overview | ScienceDirect Topics.” Sciencedirect.com, 2014, www.sciencedirect.com/topics/psychology/dual-process-theory

‌

Mayo Clinic. “Temporal Lobe Seizure - Symptoms and Causes.” Mayo Clinic, 2019, www.mayoclinic.org/diseases-conditions/temporal-lobe-seizure/symptoms-causes/syc-20378214

‌

neurominded. “Déjà Vu: The Neuroscience behind the Mysterious Phenomenon.” Inspire the Mind, 29 Aug. 2023, www.inspirethemind.org/post/d%C3%A9j%C3%A0-vu-the-neuroscience-behind-the-mysterious-phenomenon

‌

Obringer, Lee Ann. “How Déjà vu Works.” HowStuffWorks, 11 Apr. 2006, science.howstuffworks.com/science-vs-myth/deja-vu.htm

‌

Craven, Julia. “How Does Science Explain Déjà Vu? It’s a Brain Glitch with a Purpose.” Popular Science, 23 Nov. 2024, www.popsci.com/science/deja-vu-science/