Can playing Tetris ease our minds after a trauma? A study suggests it can.

When Hephaestus drove an ax into Zeus' forehead, out of his broken skull stepped Athena – fully armoured and ready for battle, according to one Greek myth. If only we had such godly grey matter. A human mind may spend hours working on a thing as common as a memory, churning out proteins to cement a recollection among neurons. Without such biological processes, though, there are no long-term memories.

And not all memories are equal. Memories from a colourful experience during, say, the family trip to Legoland probably won't cause lasting harm. But after a traumatic incident such as a car crash, rich recollections become a source of distress – what psychologists call "intrusive memories." The hours-long process that yields intrusive memories is a tempting target for scientists who want to ease victims' symptoms of trauma.

"Unlike most mental health problems, we know that intrusive memories come from a traumatic event. But the science question is how on earth do we tackle that?" Emily Holmes, a professor of psychology at the Karolinska Institute in Sweden and leader of a new study on the subject, told The Washington Post.

New research, which Holmes and her colleagues published Tuesday in the journal Molecular Psychiatry, took a unique approach to disrupting the way vivid memories are formed.

Victims of motor vehicle accidents who played the video game Tetris, during the crucial period six hours after the traumatic event, reported having fewer intrusive memories in the week after the experience.

The idea was not that playing Tetris – for the unfamiliar, a block-dropping puzzle game first released in 1984 – wiped anyone's mind. But, crucially, the game competed for the brain's visual attention.

"Our brain has limited capacity, but that's a problem we can exploit," Holmes said. "A person can't think of two visual things at the same time."

Sensory memories that linger after trauma are predominantly visual. "It's seeing the red car crash into you again, or seeing the glass shatter again," Holmes said. Tetris engages those same brain processes, too, she pointed out. "Tetris is a highly absorbing visual game – it's all symbols, no text. In your mind's eye, you see the blocks coming down. It requires visual attention and your working memory as you're trying really hard to position those blocks."

The trial study consisted of 71 patients who were involved in a motor vehicle accident and ended up in the emergency department at Oxford's John Radcliffe Hospital. Half of the patients played Tetris on a Nintendo DS. Their games lasted for about 20 minutes, including an uninterrupted stretch of 10 minutes or longer.

The scientists made sure that the Tetris players knew how to go beyond mashing the controller buttons. "We're trying to encourage them to play it in a visual way," Holmes said, "and draw on their mental imagery." Random gameplay, or even playing a nonvisual game, would not be as effective.

Researchers tasked the other group with simply jotting down what they did at the hospital, such as texting, reading or filling out crosswords.

Each patient kept a journal for a week after the accident. Any time a patient had an intrusive memory, she or he recorded the instance. The patients who played Tetris after the accident reported having an average of about nine intrusive memories - 62 percent less than the average number of distressing memories experienced by non-players.

Playing Tetris, according to Holmes, dulled or blurred visual memories. "The memory becomes less intense. It takes the edge off of it," she said. This was crucial for intrusive memories, which return because they are "overly vivid."

It would be premature for emergency departments to begin handing out Game Boys in the lobby. Mark Salter, a British consultant psychiatrist who advises the media for the Royal College of Psychiatrists, told CNN that, "The study is small . . . and not everyone plays Tetris or is computer literate." (But, he added, the idea held promise. "What's exciting about this is that it happens quickly.")

Of the accident victims in the emergency department invited to play Tetris, about half agreed to participate in the study. Those who played the game responded positively. The study quoted one Tetris novice – a woman, in her 60s, who had never played the game before – as saying, "It certainly took my mind off of it at a time when I probably would have sat brooding and feeling very sorry for myself … when you're running the whole thing through your mind and you're on your own at a vulnerable time after the ambulance crew have left you."

Still, Holmes and her co-authors are not yet convinced that Tetris would work well as a medical intervention. Rather, Holmes said she viewed the research as validation of a decade's worth of laboratory work. Previous studies suggested that visual tasks – not just Tetris but sketching, or visual games similar to Tetris like Candy Crush – would dull competing memories. This was a proof-of-concept test, she said, demonstrated in a real world situation.

Holmes said that other patient groups, such as mothers who underwent emergency C-sections or traumatic childbirths, would be worth investigating as well. Future clinical trials, she said, would only be a matter of funding.

The study raised a few questions it was not designed to answer – could Tetris, played in the same way described in the study, dull visual memories we would prefer to retain vividly?

When asked if playing video games in daily life could work this way, Holmes said, "It is possible that inadvertently performing a competing task affects intrusive memories that we would want to remember. Some people like to have intrusive memories – such as a vacation." But given how young this field was, she added, it would be too early to say for sure.

© Washington Post