“I began to indulge in the wildest fancies as I lay there in the dark, such as that there was no such town, and even that there was no such state as New Jersey. I fell to repeating the word 'Jersey' over and over again, until it became idiotic and meaningless. If you have ever lain awake at night and repeated one word over and over, thousands and millions and hundreds of thousands of millions of times, you know the disturbing mental state you can get into."

— James Thurber, “ My Life and Hard Times ,” 1933

Maybe you’ve done this as a kid. Maybe as an adult. Maybe you wondered if it was just your brain. But when you say the same word repeatedly, it suddenly seems like gibberish.

Dog, dog, dog, dog, dog, dog, dog, dog, dog, dog, dog, dog, dog, dog, dog, dog, dog.

Wait, was that a word? Didn’t it mean something a minute ago?

Semantic Satiation

This fascinating psychological phenomenon — when a word loses meaning after being repeated over and over without interruption — is called semantic satiation.

What that means is that neural systems in the brain can be fatigued by repeated stimulation, explains David Balota, a researcher and professor of psychology and neurology at Washington University in St. Louis.

“It’s just like anything you can tire,” he says. “If you lift a barbell, basically the system eventually gets tired. Think of that in a neural system: You eventually start losing the ability of these neurons to fire with repeated exposure.”

Interestingly, words with just one definition are more likely to lose their meaning during semantic satiation than words with multiple shades of meaning. For instance, every time I hear the word “dog,” I think of the same furry creature I know as a dog. But a word with various definitions, such as “cabinet” (a kitchen cabinet, a presidents cabinet of advisors), may not trigger neural fatigue in the same way.

The suggestion is that the connection between the word and its meaning and pronunciation (something known as lexical representation) starts to break down through repeated exposure to the word. When you hear "dog," you are unable to recall what that word means, making it seem nonsensical.

“My bet is this is just the consequence of any system. The more you use it, the less it will be available for the future,” Balota says. “It takes time for the neurons to re-energize themselves to where the effect of semantic satiation returns to baseline and allows you to recognize the word ‘dog’ again — typically just a few minutes."

Similar Phenomenon

Balota also studies verbal transformation effect, which is similar to semantic satiation. Here, the idea is that when you say “dog, dog, dog” repeatedly, the word typically changes to another similar-sounding word like “fog.”

“If you think about it, we have to have something in the brain that allows us to recognize this is the word ‘dog,’ ” he says. “ And it’s not necessarily the meaning of the word ‘dog,’ because there is a difference between the lexical representation for dog and your meaning for the word ‘dog.’ One allows you to recognize that’s the stimulus for the word ‘dog’ and the other allows you to access the meaning of the word ‘dog.’ ”

The word “dog” gets tired so that, by repeating it, the word becomes fatigued enough that another lexical representation, which isn’t quite as fatigued (like the word “fog”), takes over.

It’s similar to semantic satiation in the sense that it’s just another demonstration of what happens when the neural workings for your representation of a word become worn out, Balota explains.

Older adults, who process information differently, are less likely to suffer the effects of semantic satiation. Reaction time increases with age, so the theory is that the attentional system of the senior brain — which is highly related to working memory — isn’t as well tuned to the same representation of the word (like dog) as someone younger. In other words, older adults have processed the word “dog” (or any other word, for that matter) more often than younger people, so they are less likely to satiate a word in the same way. Eventually, their minds wander and they start thinking of other things before the point of nonsensicalness comes into play.

Where It Really Gets Interesting

This leads to other curious phenomena, one in which you want to experience a type of semantic satiation, like during meditation. When you sit down to meditate and employ a mantra word such as “om” to chant repeatedly, you want to clear your mind with that chant and wipe away any meaningful thoughts you’re holding at the moment. Chanting “om” allows you to focus on being in the moment and, in a sense, to use a type of semantic satiation to clear your mind, wiping thoughts away just like the word “dog” was erased when you said it over and over.

Likewise, studies show a hurtful or negative word can lose its power when said repeatedly for 45 seconds, making the hurtful word ineffective. This can be beneficial to someone who needs to neutralize a negative word. Imagine being called greedy and being hurt by the term — until you repeat it so frequently that it loses its power to harm you.

Got all that? It's a confusing topic, but now you know why it happens. (Try this word play at home — but be prepared for questions!)