Researchers say brain stimulation during sleep could improve memory processes.

Sleep is thought to consolidate memories by transferring recent experiences from the hippocampus to the frontal cortex for longer term storage.

Now, researchers from the US have found a way to improve this natural process by mildly stimulating the brain while asleep.

Participants were trained and tested on a realistic visual discrimination task in which they had to detect potentially threatening hidden objects and people such as explosive devices and enemy snipers.

The researchers found that when participants received stimulation during overnight visits to their sleep laboratory, they showed improved performance in detecting targets in similar but novel situations the next day compared to when they did not receive the stimulation, suggesting an integration of recent experience into a more robust and general memory.

The experts say overnight memory changes correlated with stimulation-induced neural changes, which could be used to optimise stimulation in future applications.

They also believe the findings provide a method for enhancing memory consolidation without disturbing sleep.