Have I Read this Before? The Brain Regions Involved in Déjà Vu
By Honoreé Brewton
There are conflicting sources regarding the first usage of the term déjà vu, a French term meaning “already seen” (Merriam-Webster), but it can be traced back to the late 1800s (Brown, 2003). Early psychologists who studied the phenomenon classified it as a disorder or illusion of memory. One of those psychologists, William James, explained in his textbook, “There is a curious experience which everyone seems to have had—the feeling that the present moment in its completeness has been experienced before…” (James, 1890). The science behind déjà vu is complex and still a bit of a mystery. Researchers continue to study how the brain functions during déjà vu and its associated pathologies.
Researchers continue to study how the brain functions during déjà vu and its associated pathologies.
Dr. Anne Cleary, a cognitive psychologist at Colorado State University, studies human memory and déjà vu. In a CNN article, she explains her thoughts on the phenomenon. “[J]ust because something fails to be recalled doesn’t mean that the memory isn’t still ‘in there’ somewhere… [t]hese types of memories might be what drive the sense of familiarity that presumably underlies déjà vu.” In a 2009 study, Cleary and colleagues tested the hypothesis that déjà vu stems from similarities between a new situation and a situation from one’s past. They enlisted participants to observe multiple scenes, with some sharing similar images or shapes. Participants who viewed a novel scene that was arranged similarly to a previously observed scene were more likely to report feelings of déjà vu (Cleary et al., 2009). This supports the notion that feelings of déjà vu are driven by familiarity and similarity to previous experiences.
Dr. Akira Robert O’Connor is a cognitive psychologist at the University of St. Andrews in Scotland, and he investigates how humans make decisions about their memories. In an article published by Scientific American, he explains that déjà vu may occur when certain brain regions that recall familiar contexts get activated erroneously. When this happens, another part of the brain fact-checks this familiarity with one’s past experiences and finds there is no matching memory. He says of the phenomenon, “All of these experiences I’m having don’t quite match up… it feels like an error.”
Participants who viewed a novel scene that was arranged similarly to a previously observed scene were more likely to report feelings of déjà vu.
In a study conducted under O’Connor’s supervision, researchers used functional Magnetic Resonance Imaging to identify multiple brain regions that were activated during so-called “mnemonic conflict,” or memory conflict, in déjà vu (Urquhart et al., 2021). These regions include the medial prefrontal cortex, which is involved in memory and decision-making (Euston et al., 2012); the parietal cortex, which is involved in sensory perception (Yao et al., 2020); and the anterior cingulate cortex, which is involved in emotion regulation and goal-directed behaviors (Rolls, 2019). In this study, researchers were able to pinpoint regions of the brain that may be involved in the déjà vu phenomenon.
It can be difficult to investigate déjà vu in a laboratory setting because the experience occurs spontaneously. However, neuropathologies like epilepsy provide another angle for researchers to study. According to Dr. Jean Khoury, a neurologist at the Cleveland Clinic, epilepsy can cause miscommunication between brain regions that are involved in memory storage and familiarity, such as the hippocampus and the parahippocampal gyrus (Brain and Spine, 2022). Within the temporal lobe (an area that helps us remember language, recognize people, and understand emotions) rests the rhinal cortex, and stimulating the rhinal cortex of epileptic patients can induce feelings of déjà vu (Bartolomei et al., 2012). It’s important to note that déjà vu does not always signal an epileptic episode.
Approximately two-thirds of the world population experiences déjà vu at least once in their lifetime (Brown, 2003), and the frequency at which it occurs decreases as we get older (Brown, 2003; Funkhouser & Schredl, 2010). Research shows that it occurs more frequently in people with higher education status (Adachi et al., 2003) and in people who watch more movies and travel regularly (Cleary, 2008). Studying epilepsy patients can further our understanding of the déjà vu phenomenon; vice-versa, déjà vu can help us better understand the mechanisms of epilepsy.
When was the last time you experienced déjà vu?
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Written by Honoreé Brewton
Illustrated by Sneha Chaturvedi
Edited by James Cole, Liza Chartampila, Lauren Wagner, and Zoe Dobler
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References
Adachi, N., Adachi, T., Kimura, M., Akanuma, N., Takekawa, Y., & Kato, M. (2003). Demographic and psychological features of déjà vu experiences in a nonclinical Japanese population. The Journal of nervous and mental disease, 191(4), 242–247. https://doi.org/10.1097/01.NMD.0000061149.26296.DC
Bartolomei, F., Barbeau, E. J., Nguyen, T., McGonigal, A., Régis, J., Chauvel, P., & Wendling, F. (2012). Rhinal–hippocampal interactions during déjà vu. Clinical Neurophysiology, 123(3), 489-495. https://doi.org/10.1016/j.clinph.2011.08.012
Brain and Spine. (2022, October 24). Deja Vu: What It Is and Why It Happens. Cleveland Clinic. Retrieved February 9, 2023, from https://health.clevelandclinic.org/deja-vu-what-it-is-and-when-it-may-be-cause-for-concern/
Brown, A. S. (2003). A review of the déjà vu experience. Psychological Bulletin, 129(3), 394–413. https://doi-org.libproxy.lib.unc.edu/10.1037/0033-2909.129.3.394
Cleary, A. M. (2008). Recognition Memory, Familiarity, and Déjà vu Experiences. Current Directions in Psychological Science, 17(5), 353–357. https://doi.org/10.1111/j.1467-8721.2008.00605.x
Cleary, A. M., Ryals, A. J., & Nomi, J. S. (2009). Can déjà vu result from similarity to a prior experience? Support for the similarity hypothesis of déjà vu. Psychonomic bulletin & review, 16, 1082-1088.
Euston, D. R., Gruber, A. J., & McNaughton, B. L. (2012). The role of medial prefrontal cortex in memory and decision making. Neuron, 76(6), 1057–1070. https://doi.org/10.1016/j.neuron.2012.12.002
Funkhouser, A. T., & Schredl, M. (2010). The frequency of déjà vu (déjà rêve) and the effects of age, dream recall frequency and personality factors. International Journal of Dream Research, 3(1), 60–64. https://doi.org/10.11588/ijodr.2010.1.473
James, W. (1890). The principles of psychology, Vol. 1. Henry Holt and Co. https://doi.org/10.1037/10538-000
Merriam-Webster. (n.d.). Déjà vu. In Merriam-Webster.com dictionary. Retrieved February 9, 2023, from https://www.merriam-webster.com/dictionary/d%C3%A9j%C3%A0%20vu
Rolls E. T. (2019). The cingulate cortex and limbic systems for emotion, action, and memory. Brain structure & function, 224(9), 3001–3018. https://doi.org/10.1007/s00429-019-01945-2
Urquhart, J. A., Sivakumaran, M. H., Macfarlane, J. A., & O’Connor, A. R. (2021). fMRI evidence supporting the role of memory conflict in the déjà vu experience. Memory (Hove, England), 29(7), 921–932.https://doi.org/10.1080/09658211.2018.1524496
Yao, J. D., Gimoto, J., Constantinople, C. M., & Sanes, D. H. (2020). Parietal Cortex Is Required for the Integration of Acoustic Evidence. Current biology : CB, 30(17), 3293–3303.e4. https://doi.org/10.1016/j.cub.2020.06.017
