Behind the Brain

Deja Vu. It’s the feeling of familiarity in an unfamiliar setting. Until recently, most scientists couldn’t explain this strange phenomenon. But over the last decade, several studies have come out with neurological explanations for deja vu. But before looking at our most modern scientific explanation, let’s take a stroll through history.

Supernatural Explanations

In the years 500-400 BC, Hindu and Greek texts talked about past lives and reincarnations. They then mentioned how memories from past lives similar to a new experience in this life could be a cause of deja vu. During the Middle Ages in medieval Europe, brought a more ominous aspect to deja vu, thinking of it as an omen from divine beings. Then, in 1788, a German philosopher, Arthur Schopenhauer brought back the idea of reincarnation to Europe. However, a French scientist in 1876, Emile Boirac, classified deja vu as scientific, calling it a phenomenon related to memory, rather than spirituality, thus causing the development to more scientific theories.

1900s Scientific Theories

1. Memory Malfunction Hypothesis (1930s): When classifying a new experience, the brain might mistakenly recognize it as a memory, thus causing deja vu.
2. Freud’s Psychoanalytic Theory (1940s): Freud (considered the father of psychology) proposed that deja vu was the brain recognizing repressed memories such as subconscious desires or traumas.
3. Temporal Lobe Epilepsy Connection (1955): A neurosurgeon called Wilder Penfield thought deja vu was a precursor to seizures in the temporal lobe.
4. Dual Processing Theory (1960s): Psychologists suggested that deja vu happens when perception and memory recall aren’t coordinating.
5. False Memory Hypothesis (1980s): Researchers thought that certain situations incorrectly activated certain parts of the brain, causing deja vu.

The Modern 21st Century Explanation

In 2012, researchers found that deja vu happens in brain circuits that differentiate from active memory recall and familiarity, thus proposing that deja vu may be due to familiar situations that we haven’t actually explored before. How can they be familiar if we haven’t explored them? Alan Brown published papers on this topic, highlighting that the positioning of certain furniture, the layout of a building, or even conversations could trigger deja vu. VR studies that showed that participants placed in multiple similar buildings experienced higher levels of deja vu, supported Brown’s thesis, thus making his theory one of our best explanation of deja vu.