If you play a lot of Tetris, you may notice aspects of the game seeping into your everyday life. Regular gameplay can cause a psychological phenomenon called the “Tetris Effect,” and a surprising number of people experience it daily.

What Is The Tetris Effect?

The Tetris Effect gets its name from the legendary 1984 video game. In case you forgot, the goal of Tetris is to fit together tetromino shapes as they fall from the sky to make a solid line. When you complete a line, it disappears. However, the Tetris Effect doesn’t take hold during gameplay—it comes later.

People who play Tetris for long periods of time see the shapes of the game in the real world and their dreams. These individuals look at parking lots, buildings, or supermarket shelves and know which game pieces would fit perfectly in the open spaces. The underlying cause of this effect is repetition.

Even though we call this phenomenon the Tetris Effect, plenty other games can trigger it. Some people see products on a shelf and know which type of Angry Bird they would need to knock everything down. Even jigsaw puzzles, dominoes, pool, or chess can cause these sensations.

Again and Again and Again

Why do we love repetition in games so much? It has something to do with our dreams and the way we learn. In 2000, Doctor Robert Stickgold and his Harvard Medical School colleagues conducted a study to figure out what was happening in subjects’ brains after repeatedly playing Tetris.

Out of the 17 subjects involved in the study, 60 percent reported that they dreamed about the images in the game. By notating when the study participants saw the shapes during their sleep cycle, Stickgold and his researchers deduced that dreaming is one way the brain reinforces learning.

Adam Sinicki, a psychology writer, explains Stickgold’s findings on the website Health Guidance:

“What’s going on then instead is that the brain is ‘practicing’ the skills that it thinks it is likely to need during the day. As you are consistently repeating the same tasks, your brain assumes that you are likely to need those skills again. You will form new neural networks by repeatedly using the same skills, and these will then fire and strengthen during the day and night in order to allow for improved performance.”

A more recent study showed that test subjects’ cerebral cortex grew in size after playing Tetris for 1.5 hours a week for three months. This solidified the idea that when we learn something new, our brains become more and more efficient with repetition. Our synaptic connections become stronger and activate quicker the more we do something.

Tetris Your Way to Happiness

We know the key to mastering a new skill a result of how much time we spend working on it, but can we apply this process to our personal habits and mental health? The answer is yes. We can change our outlook with positive thinking and practice, practice, practice.

It’s easier for our brains to recognize and latch onto negative experiences. This self-preserving trait helped us avoid threats back in our hunter-gatherer days. However, since we no longer need to assess our safety constantly, the negativity loop can be detrimental to our mental health.

The good news is that we can rewire our brains by building positive habits. Like researchers discovered with the Tetris studies, the more we do something, the faster and more efficient our brains get at that task. The situation is no different when trying to make positive responses more automatic, rather than always seizing on something negative.

Shawn Achor, the author of The Happiness Advantage, writes, “We can retrain the brain to scan for the good things in life-to help us see more possibility, to feel more energy, and to succeed at higher levels.”

That’s even better than a good game of Tetris.