Tetris: Infiltrating Dreams and Memories Since 1984

Just before this past holiday season, I took what I thought was a novel approach to reducing daily stress: I started playing Tetris for about 15 minutes each day. After about a week I found that it was indeed helping me wind down at the end of each day, but I also noticed that my gameplay was improving much faster than I’d expected. Then a few days later, it happened—I started dreaming about tetrominoes, the little four-block figures at the heart of the game.

As strange as it sounds, this phenomenon is common to many if not all regular Tetris players. In 1994, a Wired magazine article dubbed the game’s entry into dreams and real-life the Tetris effect. The author, Jeffrey Goldsmith, described a weeklong Tetris bender in Tokyo in which he started to visualize tetrominoes in floor tiles and unconsciously tried to combine people, cars, and trees when out of the house. Tetris seems like the most potent video game equivalent of an earworm, and playing it regularly more or less ensures that its shapes will come back to visit in unexpected places.

The Tetris effect is a well-known example of hypnagogic imagery, or images that appear during the transitional state from wakefulness to sleep. Many people see, feel, taste, or smell sensations they experienced that day just before falling asleep (the period known as hypnagogia), especially when their experiences are novel. But Tetris appears to have a unique effect on the brain, as shown by a 2000 study by Harvard psychiatrist Robert Stickgold. Stickgold recalled that when he was mountaineering in Vermont, he could still feel the rocks under his hands as he was drifting off to sleep. Intrigued at this phenomenon and not wanting to press study volunteers into climbing a mountain, he decided to study the effects of Tetris instead. Interestingly, he also ran the study on five amnesiacs who had short-term memory loss due to brain damage. All his participants, even the amnesiacs, reported seeing falling tetrominoes while falling asleep, but none could report seeing the computer, keyboard, or any other details about the environment. The amnesiacs could not remember the name or face of the study administrator or having played Tetris at all, but they still reported seeing “shapes floating down a screen.”

Stickgold theorized that the brain seemed to have extracted the tetrominoes and stored them in the neocortex, where general information and facts are stored apart from actual events. This is in contrast to the hippocampus, the area of the brain containing information about life events, and an area permanently damaged in someone with complete amnesia. Stickgold also posited that the study supports the theory that sleep seems to function as a pre-defined time to process and store recent memories.

Since the Tetris effect was formally named 22 years ago, a number of research groups have found the game to have interesting and wide-reaching effects on the brain and cognition. Moderate daily use increases general cognitive functions like critical thinking and general processing, as well as cerebral cortex thickness. This might explain why even casual players are able to rapidly improve their gameplay. The game may have some niche uses in psychology and medicine as well. A 2009 Oxford University research group found that Tetris could be useful in reducing or lessening PTSD flashbacks, and a separate study found that playing the game corrected amblyopia (lazy eye) in adolescents more effectively than patching the patient’s well eye.

Despite its simplicity and age, the lowly Tetris is still one of the most intriguing and useful games out there. Not too shabby for a 32-year-old Soviet side project.

Image credit: @joefoodie / CC BY 2.0