It's a dream long held by science-fiction writers: that one day we will be able to erase painful memories and create happy ones. But now scientists at Oxford University say that fiction is closer to reality than we might have thought. For they are on the cusp of developing technology that will enable us to rub out difficult episodes from the past, and make the best ones even better. By electronically tinkering with brain waves that cement our memories in place, we may soon be able to treat conditions including amnesia and post-traumatic stress disorder by removing what causes us distress altogether, said researcher Laurie Pycroft. Using the same techniques we will be able to insert what are being described as'memory prostheses' to enhance our recollections or even create new ones. The idea was the basis for the 1990 film Total Recall, based on a short story by Philip K Dick, in which Arnold Schwarzenegger's character Douglas Quaid takes a virtual vacation – only to discover the life he thought he was leading was a lie.