Jamais vu: how repetition can make familiar things seem strange

Repetition has an odd effect on the mind. Consider déjà vu: the occasion when we mistakenly feel that a new situation has happened before, producing an eerie impression of familiarity.

Yet our work suggests that déjà vu offers a glimpse into how the memory system operates.

Our research showed that it occurs when the brain region responsible for detecting familiarity falls out of step with reality. Déjà vu acts as an alert to that mismatch: a form of "fact checking" within the memory system.

Repetition, however, can produce an even stranger effect.

The reverse of déjà vu is "jamais vu", in which something you know is familiar suddenly seems unreal or somehow new. In recent research that has just received an Ig Nobel award for literature, we examined the process underlying this experience.

Jamais vu can happen when you look at a well-known face that abruptly appears odd or unfamiliar. Musicians may experience it briefly when they lose their place in a passage they know extremely well. You may also have felt it when travelling to a familiar location, becoming disorientated or viewing it with "new eyes".

It is rarer than déjà vu and may be even more disconcerting. When people describe it in questionnaires about everyday experiences, they offer accounts such as: "While writing in my exams, I write a word correctly like 'appetite' but I keep looking at the word over and over again because I have second thoughts that it might be wrong."

In ordinary life, repetition or prolonged staring can bring it on, although neither is essential. One of us, Akira, experienced it while driving on the motorway and had to stop on the hard shoulder so that his unfamiliarity with the pedals and steering wheel could "reset". Fortunately, it seldom occurs outside the laboratory.

Inducing jamais vu through repetition

We know relatively little about jamais vu. However, we suspected it would be quite straightforward to produce in a laboratory. Asking somebody to repeat something continually often causes it to seem confusing and devoid of meaning.

That was the central approach in our jamais vu experiments. In the first study, 94 undergraduate students repeatedly wrote the same word. They did this using twelve words, ranging from common examples such as "door" to less frequent ones such as "sward".

Participants were instructed to write each word as quickly as they could. They could stop whenever they wished, and we gave several possible reasons for doing so, including feeling strange, boredom or a painful hand.

The most frequent reason for stopping was that the task had started to feel strange. About 70% stopped at least once because they experienced what we classified as jamais vu. This generally happened after roughly one minute (33 repetitions), typically when writing familiar words.

In a second experiment, we used only the word "the", on the basis that it is the most common word. On this occasion, 55% of participants stopped writing for reasons that matched our definition of jamais vu (although after 27 repetitions).

Their descriptions ranged from "They lose their meaning the more you look at them" to "seemed to lose control of hand". Our favourite was: "it doesn't seem right, almost looks like it's not really a word but someone's tricked me into thinking it is."

From school punishment to laboratory research

It took around 15 years for us to write up and publish this scientific study. In 2003, we followed a hunch that repeatedly writing a word would make people feel odd. One of us, Chris, had noticed that repeatedly writing lines as a punishment at secondary school made him feel peculiar, as though the writing was not real.

The 15-year delay was because we were not as clever as we had imagined. The idea was not as novel as we believed. In 1907, Margaret Floy Washburn, one of psychology's overlooked founding figures, published an experiment with a student demonstrating the "loss of associative power" in words stared at for three minutes. Over time, the words became strange, lost their meaning and appeared fragmented.

We had simply reinvented the wheel. These introspective approaches and investigations had fallen out of favour within psychology.

What jamais vu reveals about the mind

Our distinctive contribution is the proposal that repetition-driven changes and losses of meaning are accompanied by a specific sensation: jamais vu.

Jamais vu tells you that something has become excessively automatic, fluent or repetitive. It helps us "snap out" of our current processing, and the sense that things are unreal is actually a reality check.

This need for such a mechanism is understandable. Cognitive systems must remain flexible, enabling us to direct attention where it is required rather than becoming trapped in repetitive activities for too long.

We are still only beginning to understand jamais vu. The leading scientific explanation is "satiation" - overloading a representation until it no longer makes sense.

Related theories include the "verbal transformation effect", where saying a word repeatedly activates its so-called neighbours. For instance, listeners may initially hear the looped word "tress" again and again, but then report hearing "dress," "stress," or "florist".

It also appears connected with research on obsessive compulsive disorder (OCD), which has examined the consequences of compulsively staring at objects, including lit gas rings. As with writing repeatedly, the effects are unusual and reality can begin to slip away, but this could help us understand and treat OCD.

If continually checking that a door is locked makes the task lose its meaning, it becomes hard to tell whether the door is actually locked, creating a vicious cycle.

Ultimately, we are pleased to have received the Ig Nobel prize for literature. Winners of these prizes produce scientific work that can "make you laugh and then make you think".

We hope that our research into jamais vu will encourage further research and deliver deeper insights in the near future.

Akira O'Connor, Senior Lecturer in Psychology, University of St Andrews and Christopher Moulin, Professor of cognitive neuropsychology, Université Grenoble Alpes (UGA)

This article is republished from The Conversation under a Creative Commons licence. Read the original article.

An earlier version of this article was published in September 2023.