The Tetris effect occurs when people devote so much time and attention to an activity that it begins to pattern their thoughts, mental images, and dreams.

The Tetris effect takes its name from the video game Tetris.

People who played Tetris for a prolonged amount of time could find themselves thinking about ways different shapes in the real world can fit together, such as the boxes on a supermarket shelf, the buildings on a street, or hallucinating pieces being generated and falling into place on an invisible layout.

In this sense, the Tetris effect is a form of habit. They might also dream about falling tetrominos when drifting off to sleep or see images of falling tetrominos at the edges of their visual fields or when they close their eyes. In this sense, the Tetris effect is a form of hypnagogic imagery.

Other examples

The Tetris effect can occur with other video games. It has also been known to occur with non-video games, such as the illusion of curved lines after doing a jigsaw puzzle, or the involuntary mental visualization of Rubik’s Cube algorithms common amongst speedcubers.

On a perceptual level, sea legs are a kind of Tetris effect. A person newly on land after spending long periods at sea may sense illusory rocking motion, having become accustomed to the constant work of adjusting to the boat making such movements (see “Illusions of self-motion” and “Mal de debarquement).

On a mental level, computer programming has resulted in dreams about coding. Mathematicians have reported dreaming of numbers or equations, for example, Srinivasa Ramanujan, or Friedrich Engels who remarked:

“last week in a dream I gave a chap my shirt-buttons to differentiate, and he ran off with them”.

Place in cognition

Stickgold et al. (2000) have proposed that Tetris imagery is a separate form of memory, likely related to procedural memory.

This is from their research in which they showed that people with anterograde amnesia, unable to form new declarative memories, reported dreaming of falling shapes after playing Tetris during the day, despite not being able to remember playing the game at all.

A study, conducted by Lynn Okagaki and Peter Frensch in 1994, showed that participants who played Tetris for twelve 30-minute sessions (with no previous experience of the game) did much better than the control group in both the paper-pencil test version of spatial skills as well as the computerized version.

The conclusions drawn from this experiments were that video games such as Tetris had a positive effect on three areas of spatial skills including mental rotation, spatial perception and spatial visualization in those who played for a prolonged period continuously.

In 2009, the BioMed Central (BMC) study about the Tetris effect used an MRI to scan the brains of subjects. The experiment tested two groups of people, one of which was the group who played Tetris for 30 minutes a day and the other one was the group who didn’t play at all.

The researchers found, by using the MRI images, that the gray matter of the subjects who played Tetris had thickened, compared to the people who had never played it.

The result proves that this game is responsible for physical cognitive development, which also improves memory capacity. Tetris has been found to act upon this flexibility of brain matter by thickening it.

According to the BMC study, it appears to link gray matter plasticity to the brain’s efficiency, but there is no substantial research making these claims that have been published at this time. It can be assumed that playing Tetris affects the brain in a healthy way, such as allowing your brain to operate more efficiently.

Another 2009 Oxford study suggests that playing Tetris-like video games may help prevent the development of traumatic memories.

If the video game treatment is played soon after the traumatic event, the preoccupation with Tetris shapes is enough to prevent the mental recitation of traumatic images, thereby decreasing the accuracy, intensity, and frequency of traumatic reminders.

We suggest it specifically interferes with the way sensory memories are laid down in the period after trauma and thus reduces the number of flashbacks that are experienced afterward,” summarizes Dr. Emily Holmes, who led the study.

Game Transfer Phenomena

A series of empirical studies with over 6,000 gamers have been conducted since 2010 into Game Transfer Phenomena (GTP), a broadening of the Tetris effect concept coined by Dr. Angelica B. Ortiz de Gortari in her seminal thesis on GTP.

GTP is not limited to altered visual perceptions or mental processes but also includes auditory, tactile and kinaesthetic sensory perceptions, sensations of unreality, and automatic behaviors with video game content.

GTP establishes the differences between endogenous (e.g., seeing images with closed eyes, hearing music in the head) and exogenous phenomena (e.g., seeing power bars above people’s head, hearing sounds coming from objects associated with a video game) and between involuntary (e.g., saying something involuntarily with video game content) and voluntary behaviours (e.g., using slang from the video game for amusement).


The earliest known reference to the term appears in Jeffrey Goldsmith’s article, “This Is Your Brain on Tetris“, published in Wired in May 1994:

No home was sweet without a Game Boy in 1990. That year, I stayed “for a week” with a friend in Tokyo, and Tetris enslaved my brain. At night, geometric shapes fell in the darkness as I lay on loaned tatami floor space. Days, I sat on a lavender suede sofa and played Tetris furiously. During rare jaunts from the house, I visually fit cars and trees and people together. […]

The Tetris effect is a biochemical, reductionistic metaphor, if you will, for curiosity, invention, the creative urge. To fit shapes together is to organize, to build, to make deals, to fix, to understand, to fold sheets. All of our mental activities are analogous, each as potentially addictive as the next.

The term was rediscovered by Earling (1996), citing the use of the term by Garth Kidd in February 1996. Kidd described “after-images of the game for up to days afterward” and “a tendency to identify everything in the world as being made of four squares and attempt to determine ‘where it fits in’“.

Kidd attributed the origin of the term to computer-game players from Adelaide, Australia. The earliest description of the general phenomenon appears in Neil Gaiman’s science fiction poem “Virus” (1987) in Digital Dreams.

The ending of The Witness resembles the Tetris effect, where the unnamed protagonist is taken out of the game’s virtual reality and sees the game’s puzzles in real-world objects.

*This article was originally published at