Past studies have indicated that people who played the computer game Tetris within 4 hours of watching video footage of traumatic events were less likely to have fewer unwanted memories of those events.
However, Holmes and colleagues note that it is unrealistic to expect people who are involved in a traumatic event to play a computer game in the 4 hours following. But could doing so within 24 hours help reduce occurrence of unwanted memories?
Twenty-four hours after watching the film, half of the participants were shown stills from it as a way of reactivating their memories. They then took part in a 10-minute filler task - allowing time for memory reconsolidation to begin - followed by 12 minutes of playing Tetris. The other half of the participants acted as controls, only taking part in the filler task before sitting quietly for 12 minutes.
Over the next week, all participants were required to keep a diary of any intrusive memories that occurred - defined as "scenes of the film that appeared spontaneously and unbidden in their mind."
The team's findings - published in the journal Psychological Science - revealed that the participants whose memories were reactivated before playing Tetris experienced fewer intrusive memories from the film than the control group.