I went to the Internet to look up what it’s called when I go to bed and involuntarily start reliving some activity I tried that day. Does no one else get this? If I go skiing, I fall asleep feeling like I’m skiing. Same for if I’ve been on a boat or on roller coasters or, apparently, hiking along the Grand Canyon. I can’t find a specific name for that phenomenon, which makes me suspect it’s not as common as I figured. It seems to be one of many odd features of hypnagogia, the transitional period between wakefulness and sleep.

But the search led me to this. From the Wikipedia: Tetris Effect.

The Tetris Effect refers to when people spend so much time on an activity — like, say, a particularly addictive video game — that it begins to dominate their thoughts, mental images and dreams.

One of the first published references to the term came in 1996, or, as it was better known to Tetris-effect sufferers, . Australian researched Garth Kidd called it, “a tendency to identify everything in the world as being made of four squares and attempt to determine ‘where it fits in.'” In an article for Philadelphia’s CityPaper that same year, Annette Earling described:

Raised pulse rate, tightened stomach muscles, strange dreams, and the squares… ohhh, the falling squares. I saw them everywhere, and when I didn’t see them in skylines or grocery aisles, I had only to close my eyes and there they were behind my eyelids, falling faster and faster as I furiously rotated them mentally.

According to the Wikipedia, the Tetris Effect is not limited to Tetris. Computer programmers pouring over code, rowers and mathematicians have reported comparable experiences — and lord knows the combination of copy-editing, basic html and bizarre hours required by my job on the ol’ WCSN.com prompted some similar strangeness.

The Tetris Effect as specific to Tetris is now known by the term Game Transfer Phenomenon, which is basically exactly what it sounds like. If you ever play a car-racing game for a while then drive a real car, you’re probably familiar.

But the Tetris Effect, as specific to Tetris, has some beneficial effects too. This is perhaps predictable: A 1994 study showed that people who played 12 30-minute sessions of Tetris improved against a control group in spatial skills, specifically mental rotation, spatial perception and spatial visualization.

Also the Tetris skills seem to develop in the unconscious, procedural memory, as opposed to the declarative memory where facts and knowledge reside. A research paper in 2000 “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.”

And — and here’s where it gets really weird — a 2009 study suggested that playing Tetris immediately after traumatic events can help prevent traumatic memories. The focus on the Tetris shapes prevents people from replaying the trauma in their mind, in turn “decreasing the accuracy, intensity, and frequency of traumatic reminders.”

So if you ever see something really messed-up happen that you think might haunt you forever, grab your nearest Gameboy, I guess.

The Tetris Effect should not be confused with the similarly named but entirely different phenomenon called “L’effet Tetris,” which is French for The Tetris Effect.