Wednesday January 7 2009
Tetris is a puzzle video game
Scientists have claimed that “playing the video game Tetris after a major shock could reduce the symptoms of post-traumatic stress disorder,” The Daily Telegraph reported. The newspaper said the researchers found that playing the computer game shortly after trauma helped to prevent bad memories and flashbacks.
The aim of playing Tetris was to provide a form of mental stimulation (visiospatial cognitive stimulation) that would, as the researchers put it, serve as a 'cognitive vaccine’ to prevent the flashbacks associated with PTSD from developing. This study has demonstrated its potential if used during the immediate aftermath of a traumatic event.
However, the study has several important limitations due to its small sample size and study methods. This includes the fact that it was necessary to stimulate ‘trauma’ by making the participants watch a film. How accurately this represents real life traumatic experiences is questionable. The study has positive findings, but possible applications will need much further research and consideration.
Where did the story come from?
Emily Holmes and colleagues from the University of Oxford carried out this research. The work was funded by a Royal Society Dorothy Hodgkin Fellowship, awarded to the lead author. The study was published in the peer-reviewed medical journal Public Library of Science (PloS) One.
What kind of scientific study was this?
This experimental study investigated the possibility of developing a ‘cognitive vaccine’ that would prevent the flashbacks associated with post traumatic stress disorder (PTSD). These flashbacks are a feature of the disorder, and can occur up to six months after people experience extreme emotional or physical trauma. Currently, there are successful treatments for PTSD, but a lack of early intervention treatments to prevent the full disorder from developing.
The researchers base their theory of using cognitive stimulation to prevent PTSD symptoms on the fact that the brain has selective resources and limited capacity. They say there is also the possibility that there is a ‘six-hour window’ after an event in which to disrupt the consolidation of memories. Flashbacks were chosen to be studied as they are the hallmark symptom of PTSD. As flashbacks are visiospatial mental images, the researchers thought that a visiospatial computer game such as Tetris might compete for the mind’s resources to generate mental images if exposure occurred within six hour after a traumatic event.
The researchers used the ‘Trauma Film’ method because this technique can generate flashbacks similar to those of PTSD. Previous studies have also demonstrated that the frequency of these flashbacks can be manipulated by the viewer who completes cognitive visiospatial tasks while watching the film.
Here, the researchers wanted to test whether an effect could be obtained from similar cognitive stimulation, which was experienced shortly after the traumatic film rather than during it. As standard neuropsychological visiospatial testing was considered impractical, Tetris was chosen because it is known to intrude upon image-based memory (people see images of the game at a later time after playing).
For the study, the researchers recruited 40 participants who each watched a 12-minute film of trauma, injury or death. The participants were then given a 30-minute interval before being randomly divided so that half received the 10-minute visiospatial intervention (playing Tetris) while the other half were left to sit quietly with no intervention. During the following week, the participants kept a daily diary of their flashbacks and then returned to the laboratory for clinical testing of flashback symptoms. They also completed a recognition memory test of the film to see whether their voluntary memory of the film remained intact.
What were the results of the study?
The two test groups were comparable in age (22-24) and had no differences in levels of depression or anxiety. They also did not differ in their mood response to the film. During the 10-minute intervention period, those playing the game experienced significantly fewer flashbacks than those sitting doing nothing. During the following week, those in the Tetris group reported significantly fewer traumatic flashbacks than those in the non-intervention group. These results were also confirmed by clinical testing. Recognition memory testing showed no difference between the groups in voluntary memory.
What interpretations did the researchers draw from these results?
The researchers conclude that playing the visiospatial game Tetris 30 minutes after seeing traumatic material reduces involuntary flashbacks while simultaneously preserving voluntary recall memory of the event.
They suggest that in the aftermath of a traumatic event, aspects of human memory may be influenced using cognitive stimulation, and that this has implications for novel preventative treatments.
What does the NHS Knowledge Service make of this study?
This study has demonstrated the potential use of cognitive stimulation in the immediate period following traumatic exposure for the prevention of PTSD. However, the study has several important limitations:
- With only 40 participants, the study was small, and there is the possibility that the findings were arrived at by chance. Additionally, the participants were all young and healthy and may not be representative of all population groups.
- Although the study used ‘simple random assignment’ to allocate people into the two groups, this cannot be assumed to be a carefully controlled trial. Neither the participants nor the assessors were blinded (unaware) as to whether the person had played Tetris or not. As the participants may have also known the objective of the study, this is likely to bias their reporting of flashbacks, however unintentionally. For example, those who played the game could have been influenced so that they thought about the game instead of the film.
- Although the Trauma Film has previously been demonstrated to induce flashbacks, it is not directly comparable to experiencing real life trauma (either personally or through others), which may have involved real pain and suffering. This short 30-minute duration of ‘traumatic’ exposure would not be representative of many traumatic situations, such as a war zone. Additionally, the one-week assessment period used here is unlikely to cover the longer duration of PTSD experienced in real-life.
- The opportune time for cognitive exposure to be effective is said to be in the six-hour period after a traumatic event, which would make its use as a therapy difficult to implement in many cases. Here, the treatment took place just 30-minutes after the event, a time period that would be impossible in most trauma cases.
- The news reports have focused on the game Tetris because this was used in the study. However, this was only used for ease of testing, and other visiospatial cognitive tasks may be similar or more effective.