In a series of experiments, Oxford scientists have learned that Tetris, the popular puzzle video game that debuted more than a quarter-century ago, may have a unique ability to limit the effect of traumatic memories.

Earlier studies at Oxford had shown that playing Tetris after traumatic experiences could reduce flashbacks in healthy volunteers. Not all video games have this special ability, however. A newer series of experiments show that while Tetris lessened flashbacks, Pub Quiz Machine 2008--a trivia quiz game--actually increased their frequency.

The Oxford team showed a film containing traumatic scenes of injury to study volunteers. After a 30-minute wait, 20 volunteers played Tetris for 10 minutes, 20 played Pub Quiz for 10 minutes and 20 did nothing.

The group that played Tetris had "significantly fewer flashbacks" of the film than those who did nothing. Interestingly, the Pub Quiz players experienced far more flashbacks. In a second test, the post-film wait was extended to 4 hours. Again, the Tetris group had substantially fewer flashbacks.

"Our latest findings suggest Tetris is still effective as long as it is played within a four-hour window after viewing a stressful film," said Dr. Emily Holmes of Oxford University's Department of Psychiatry, in a statement.