Scientists have found a way to wiping out painful memories without using drugs.
They have shown that when we recall a powerful memory, there is a brief window of opportunity it which it can be 'rewritten' for the better.
The finding could one day be used to help soldiers erase the horrors of battle, as well as those haunted by memories of car crashes and sufferers of crippling phobias.
Although much research is being carried out into ways of blocking traumatic memories, most of it centres on drugs that could have unwanted side-effects.
Characters in the Eternal Sunshine of the Spotless Mind had their bad memories wiped. Now scientists think they can do it for real
Elizabeth Phelps, of New York University, said: 'Our results suggest a non-pharmacological, naturalistic approach to more effectively manage emotional memories.
To create bad memories, Professor Phelps gave a group of volunteers mild electric shocks while they looked at a picture of a coloured square. This taught them to associate the image with fear.
On the second day they given the picture-shock combination once more, before being repeatedly shown the picture alone.
When the were shown the 'scary' picture again on the third day, their fear had all but gone, and the effect lasted for at least a year, the journal Nature reports.
For the technique to work, two things about the procedure on the second day were key.
The volunteers had to be given the picture-shock combination at the start of the second day, as a means of bringing the painful memory back to the surface.
And the repeated showing of the picture minus the shock, had to occur shortly afterwards.
The technique worked when the image was repeatedly shown within 10 minutes of giving the picture-shock combination, but not when it was shown six hours later.
With animal experiments giving similar results, it seems that our memories are not set in stone. Instead, they can updated with new information during a brief period between being retrieved and re-stored.
It seems that our memories are not set in stone and bad ones can be retrieved and re-stored within a six hour period
Professor Phelps said: 'Timing may have a more important role in the control of fear than previously appreciated.
'Our memory reflects our last retrieval of it rather than an exact account of the original event.'
Researcher Dr Daniela Schiller said: 'Our research suggests that during the lifetime of a memory there are windows of opportunity where it becomes susceptible to become permanently changed.
'By understanding the dynamics of memory we might, in the long run, open new avenues of treatments for disorders that involve abnormal emotional memories.'
The researchers are unsure exactly how the finding would be put into practice on patients.
But they believe it offers hope of a more natural alternative to memory-erasing drugs under research.
Earlier this year, Dutch researchers showed that beta-blocker drugs used to treat heart disease can impact on memory.
Other researchers have had success with anaesthetic gases.
However, the field is not without its critics, with some claiming that holding onto and reviewing bad memories helps us learn from our mistakes.
The ability to remove memories has been the stuff of science fiction for decades.
In the film the Eternal Sunshine of the Spotless Mind, a couple played by Kate Winslet and Jim Carrey, used a technique to erase memories of each other when their relationship turned sour.
