Melbourne: The best way to `remember` something important is to remember it while you are asleep, suggests a new study.
The research, led by Bjorn Rasch of the University of Basel in Switzerland, claims reactivating newly learned memories during sleep rather than when awake does a better job of strengthening the memory trace.
The work could have clinical implications for treating disorders such as post-traumatic stress disorder (PTSD).
The study involved training subjects in a spatial memory task to learn an object’s location in a grid. At the same time an odour was released - the idea being to associate the memory with the smell.
One group then went to sleep, while the second group stayed awake.
After about 20 minutes, while the sleeping group’s brain wave patterns were in slow wave sleep (SWS), both groups were subjected to the same odour again to reactivate the memory.
After another 20 minutes, the sleeping group were woken, and both groups were given a similar task, but the objects were in different locations and without the odour.
Half an hour later they were asked to recall the position of the cards from the original task.
Rasch and colleagues found both groups were correct about 60 per cent of the time without any odour assistance.
But once the odour was added to the test, the non-sleeping group were only correct about 42 per cent of the time, compared to the sleeping group’s 84 per cent.
"As we expected, reactivation during waking destabilized memories. In contrast, reactivation during SWS immediately stabilized memories, thereby directly increasing their resistance to interference," ABC Science quoted the researchers as saying.
The study appears in this week’s Nature Neuroscience.