London: Playing visually demanding computer games such as Tetris can help block flashbacks of traumatic events, reducing the risk of a person suffering from post-traumatic stress disorder, a new study suggests.
Unwanted, intrusive visual memories are a core feature of stress- and trauma-related clinical disorders such as posttraumatic stress disorder (PTSD).
"This work is the first to our knowledge to show that a 'simple cognitive blockade' could reduce intrusive memories of experimental trauma via memory reconsolidation processes," said senior study author Emily Holmes of the Medical Research Council Cognition and Brain Sciences Unit in the UK.
"This is particularly interesting because intrusive memories are the hallmark symptom of PTSD.
"Currently, there are recommended treatments for PTSD once it has become established, that is, at least one month after the traumatic event, but we lack preventative treatments that can be given earlier," said Holmes.
Previous research has shown that people who played the computer game Tetris shortly after viewing film of traumatic events experienced fewer intrusive memories over the following week, when they played within 4 hours of viewing the footage.
But it's unlikely that people would be able to receive such immediate treatment following a traumatic event in the real world, so Holmes and colleagues wanted to see whether they might be able to use a similar cognitive procedure to change older, already established memories a day later.
The research draws on existing memory work exploring the theory of reconsolidation as a way of making established memories malleable and vulnerable to disruption, following the reactivation of that memory.
They hypothesised that playing Tetris - an engaging visuospatial task - after memory reactivation would create a "cognitive blockade" that would interfere with the subsequent reconsolidation of visual intrusive memories. As a result, the frequency of intrusive memories would be reduced over time.
In two experiments, the researchers had participants view films that contained scenes of traumatic content as a way of experimentally inducing intrusive memories. Participants then returned to the lab 24 hours after watching the film.
In the first experiment, half of the participants had their memories of the film reactivated by viewing selected stills from the film footage, followed by a 10-minute filler task, and then 12 minutes of playing Tetris; the other participants completed only the filler task and then sat quietly for 12 minutes.
The results showed that the participants who had their memories reactivated and played Tetris experienced significantly fewer intrusive memories over the next week than the participants who came to the lab and simply sat quietly for the equivalent period of time.
A second experiment with four groups replicated the findings from first experiment. Importantly, it showed that neither reactivation nor Tetris was enough to produce these effects on their own - only participants who experienced both components showed fewer intrusive memories over time.