Study subjects who played the computer game had fewer 'flashbacks'
Playing the computer puzzle game Tetris can help reduce the effects of traumatic stress, UK researchers say.
Volunteers were exposed to distressing images, with some given the game to play 30 minutes later, the PLoS One journal reported.
Players had fewer "flashbacks", perhaps because it helped disrupt the laying down of memories, said the scientists.
It is hoped the study could aid the development of new strategies for minimising the impact of trauma.
However, the researchers accept translating their findings into practical applications could prove difficult.
Post Traumatic Stress Disorder (PTSD), often associated with experiences during conflict, can affect anyone who has suffered a sudden and shocking incident.
One of its main features is the "flashback", in which the distressing sights, sounds or smells of the incident can return in everyday life.
The Oxford University experiment works on the principle that it may be possible to modify the way in which the brain forms memories in the hours after an event.
A total of 40 healthy volunteers were enrolled, and shown a film which included traumatic images of injuries.
Half of the group were then given the game to play while the other half did nothing.
The number of "flashbacks" experienced by each group was then reported and recorded over the next week, and those who played Tetris had significantly fewer.
Dr Emily Holmes said it might produce a "viable approach" to PTSD treatment, although she acknowledged that a lot needed to be done to translate the experiment into something that could be used to help real patients.
She said: "We wanted to find a way to dampen down flashbacks - the raw sensory images of trauma that are over-represented in the memories of those with PTSD.
"Tetris may work by competing for the brain's resources for sensory information.
"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 afterwards."
She stressed that no conclusions could be drawn on the general effects of computer gaming on memory.
Dr Holmes added: "We are not saying that people with PTSD should play Tetris but we do think it is hugely valuable to understand how the brain works and how it produces intrusive flashback memories.
"Because we cannot study the genesis of real flashback memories during real trauma we need to find other approaches and this sort of cognitive science can give us models to help us better understand emotional memory."
Professor David Alexander from the Aberdeen Centre for Trauma Research stressed it was ethically impossible to simulate an event so catastrophic as the type of incident which can lead to post-traumatic stress disorder.
"The volunteers here knew that something was going to happen, but they were not going to be harmed - a genuinely traumatic incident is different in scale, and is usually completely unexpected and marked by feelings of loss of control."
He said that post-traumatic stress was normally detected and diagnosed only weeks after the event, rather than in the hours immediately afterwards, and it was very difficult to predict which people were likely to develop it.