Mental Floss

What Is the Tetris Effect?

Anyone who has ever played ‘Tetris’ knows how addictive the ’80s video game can be. Scientists say the Tetris Effect may even have psychological benefits for people coping with PTSD.
ByBeth Robertson|
The addictive ’80s game might also have psychological benefits.
The addictive ’80s game might also have psychological benefits. | Brandenads/Wikimedia Commons/Public Domain (Tetris); enjoynz/DigitalVision Vectors/Getty Images (background)

We all have hobbies, whether they involve art, sports, gaming, or anything else. But have you ever taken part in these activities for so long and with such intensity that you find yourself dreaming about them? If so, you’ll be happy to know that there is an explanation for this phenomenon—one that might hold the key to treating post-traumatic stress disorder (PTSD), learning how the brain forms dreams, and discovering how amnesia affects the brain. It’s called the Tetris Effect.

  1. Tetris Terminology
  2. Tetris to Treat PTSD
  3. Blocking Out Dreams

Tetris Terminology

Coined by journalist Jeffery Goldsmith in 1994 after the classic video game, the Tetris Effect is a phenomenon in which, after focusing on a repetitive task for an extended period of time, a person will find elements of that experience appearing in their thoughts and dreams. Using Tetris as an example, a person who has played the game for hours may start seeing mundane objects as forms that can be arranged or begin dreaming of falling blocks and potential solutions to a level they may be stuck on.

These visual effects have been dubbed cognitive afterimages: repetitive impressions that linger in the mind, such as music that gets stuck in your head, phantom phone vibrations, thinking in the voice of characters from books or TV shows, or more specific things like chess players seeing chess boards and pieces in their mind’s eye. They demonstrate the brain’s ability to hold onto and replay experiences. 

Tetris to Treat PTSD

A fascinating element of this effect is its potential ability to treat flashbacks in people with PTSD. In a 2020 study, two groups of participants were asked to take part in either standard therapy (Eye Movement Desensitization and Reprocessing, or EMDR), or standard therapy with the addition of 60 minutes of Tetris every day for approximately six weeks. After six months, the Tetris-playing group showed more volume in their hippocampuses and reported fewer PTSD symptoms, while the non-Tetris group experienced no changes.

Dr. Emily A. Holmes, a neuroscientist at Uppsala University who was not involved in the 2020 study, told ABC News why Tetris may decrease flashbacks. “Your brain can’t do two things of the same type at once,” she said. “You can’t both have a really vivid image and play Tetris.”

Blocking Out Dreams

Another interesting study into the Tetris Effect was conducted by Robert Stickgold in 2000. He experienced the effect on a rock-climbing vacation in the late 90’s: after ascending a particular mountain, he then dreamed about the same mountainside he had been climbing all day. Stickgold, a sleep researcher at Harvard, set out to discover why. 

He shared his question with a group of his students, who suggested he further investigate the effect with Tetris (rather than mountain climbing) since its repetitive gameplay was most likely to trigger the phenomenon.

Stickgold’s investigations revealed some intriguing characteristics. For one, novice Tetris players were more likely to experience the effect than masters, suggesting that the more inexperienced the brain is in a specific subject, the more likely it is to revisit the task in dreams. 

Second, the effect appears to also be present in people with amnesia. In one of Stickgold’s experiments, five of the participants had damage to their hippocampus and possessed no short-term memory, meaning that they could not remember having played the game the previous day. Yet, three of the five still had dreams about falling blocks. Stickgold noticed one of the participants placing her fingers on the correct computer keys the next day despite not remembering the game. 

“She did not quite know what she was doing, and yet she did know what she was doing,” Stickgold told Scientific American. “In a way, this is Freud’s unconscious—things activated in our brain that are in fact memories that guide our behavior, but are not conscious.”

There is still much to learn about the Tetris Effect and how it may alter our brains. Sleep and dreams have always been difficult for scientists to decipher, but a 1980s video game is proving to be an unlikely key to unlocking these mysteries.

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