Study: Playing Tetris Can Help Reduce Flashbacks

LONDON (Nov. 11) -- Picture the scene: You're lying in a hospital bed after being pulled out of a terrifying car crash. The doctors haven't found any physical injuries, but before you're allowed to leave, they hand you a Game Boy and insist you play Tetris for 10 minutes.

That might sound a little unreasonable (you're unlikely to rack up a high score in such a shaken state), but it could be seriously beneficial for your future mental health.

According to a new study by a team from Oxford University's department of psychiatry, playing that classic block-stacking game after a traumatic event can significantly reduce the occurrence of flashbacks -- the intrusive and unwanted recurring memories that are symptomatic of post-traumatic stress disorder.


And that protective effect appears to be exclusive to heavily visual video games such as Tetris. Researchers discovered that games that rely on word or language skills can actually produce more frequent flashbacks.

To unravel Tetris' soothing qualities, the Oxford researchers asked 60 mentally healthy volunteers to sit through an emotionally stressful 21-minute video containing clips of fatal car accidents and patients undergoing surgery. After a 30-minute wait, 20 participants were asked to play Tetris for 10 minutes, another 20 played the general-knowledge game Pub Quiz Machine 2008 and the final 20 did nothing. Over the next week, participants recorded their flashbacks in a diary.

The scientists found that Tetris players had around half as many flashbacks of the video as the no-game group, while those who played the general knowledge quiz had the highest level of intrusive memories.

In another experiment detailed in the study, which was published in the journal PLoS One, volunteers were asked to wait for four hours before starting play. Over the following seven days, the Tetris group again experienced fewer flashbacks than other participants.

"Both groups enjoyed the games," noted Emily Holmes, the lead researcher on the study. "But as predicted, only one had the effect of reducing intrusive memory."

So why does Tetris have this apparently unique impact? It all has to do with the way the brain creates flashbacks.

The process begins when our perceptual experience of the world (what we see, hear, taste and smell) and our conceptual experience (how we actually piece all of that sensory information together and create context) are thrown out of balance. In a combat situation, for instance, a soldier can find his conceptual experience overwhelmed by the sheer amount of perceptual information coming his way.

That imbalance can prevent the trooper from remembering the battle as a coherent set of events, leaving him instead with a memory comprised of perceptual experiences, such as the sight of muzzle flashes, the smell of gun oil and the sound of a shell-burst. Such context-free, sensory-heavy memories can cause great distress when they unexpectedly pop back into the mind, causing the sufferer to feel as though he's reliving the original incident.

However, there is a six-hour period after the initial trauma -- when the memory of the incident is being forged -- in which it's possible to act against the flashback. Each channel of the brain can only process a set amount of information. So if our perception information channel is concentrating on a visual task, such as recognizing the shape and color of different Tetris blocks, fewer resources can be applied to the job of developing images of the trauma, Holmes and her colleagues reasoned.

That theory also explains why participants who played the Pub Quiz game experienced more flashbacks. That game requires players to respond to written general-knowledge questions, a task that probably competes with the verbal and conceptual processing of the trauma. And as a person's contextual understanding of the trauma diminishes, the flashback-generating perception channel again gains the upper hand.

These findings could eventually help revolutionize the treatment of PTSD. However, Holmes says she has a long way to go before the lessons learned from this research can be put into practice.

"This is basic science. We're still trying to understand how the human mind and this phenomenon of intrusive memory works," she said. "But after a couple more studies, it would be nice to move in a more clinical direction."