Procrastinating proves useful


Playing Tetris could help reduce the effect of post-traumatic stress disorder (PTSD), a study by Oxford University psychologists has suggested.

Volunteers were shown distressing images and those who played Tetris afterwards experienced a significantly lower number of flashbacks.

Dr Emily Holmes of the Department of Psychiatry, who led the research, hopes that this could be developed to minimise the effect of trauma.

In the study, 40 healthy volunteers were shown a video which included scenes of human surgery, fatal road accidents and drowning for 12 minutes. Following a 30 minutes interval, half of them played Tetris for ten minutes, while the other half did nothing.

Over the next week, the participants kept a diary in which they recorded any flashbacks they experienced. The group who played Tetris had less than half the number of flashbacks. The probability that this was due to chance was less than one percent.

On returning to the lab, both groups were asked 32 true-or-false questions, and both groups remembered the same level of detail, so playing Tetris had no effect on how much they remembered, but only on the effect the memories had.

Dr Kadosh acknowledged that this was still at a preliminary stage. She said that: “This is only a first step in showing that this might be a viable approach to preventing PTSD…There is a lot to be done to translate this experimental science result into a potential treatment”.

She also stressed that no conclusions could yet be drawn about the general effects of computer gaming on memory.

The experiment was unrealistic in that the volunteers knew that the disturbing event would happen, and that they were safe, so a genuine shocking experience may have made them react in different ways. PTSD is also usually only detected weeks after the events, rather than 30 minutes, as in the study.

PTSD can affect anyone who has suffered a shocking and sudden incident. Flashbacks are hallmark of this condition.

The study was unique in being the only current potential treatment that would be applied before PTSD has set in. It is hoped that such a treatment has the potential to reduce the frequency of flashbacks more effectively by acting before the memory can become fixed in the brain.

The experiment depended on three elements. Firstly, the mind is considered to have two channels of thought, one is sensory and deals with our actual perceptions of the world, while the other is conceptual and gives our perceptions context by drawing meaning from our experiences. So, in a conversation, one channel would see and hear the person speaking while the other would interpret this. Secondly, that there are limits to each stream of thought. Thirdly, that there is only a short time to interfere with the way in which our memories are retained.

It is thought that Tetris should interfere with the way in which the image is retained in the sensory part of our brain, while the understanding of the images would remain unchanged. It is already known that memories are set within about six hours of the experience, and then they become etched, increasing the probability of flashbacks. Tetris can help to block the process of such memories being formed because it requires ‘visuospatial skills’.

The skills that are required in recognising the shapes and acting upon their positions quickly are the same kind of mental abilities that are used to provide the foundations for flashback images.

Dr Holmes said: “Tetris may work by competing for the brain resources for sensory information. We suggest [Tetris] 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.”

It has been shown that Tetris does not only provide a distraction. Mentally demanding tasks have previously been tested on volunteers who had viewed disturbing material, such as counting backwards in threes, but these lacked the spatial element. As such, they have actually increased the frequency of flashbacks.

Psychology student Peter Browne said: “This study is interesting because it’s looking for a way to prevent symptoms rather than treat them once they’ve started to occur, and it’s a simple cognitive intervention involving no drugs, making it cheaper to implement and easier to persuade people to try it.”

The group is hoping to develop this research further, hopefully to create an intervention to reduce flashbacks experienced in PTSD.