Researchers have found they can use drugs to wipe away single, specific memories while leaving other memories intact. By injecting an amnesia drug at the right time, when a subject was recalling a particular thought, neuro-scientists discovered they could disrupt the way the memory is stored and even make it disappear.

The research suggests memories can be manipulated because they act as if made from glass, existing in a molten state as they are being created, before turning solid. When the memory is recalled, however, it becomes molten again and so can be altered before it once more resets.

The researchers used propranolol, a drug normally used to treat hypertension in heart disease patients but also known to cause memory problems. They treated 19 accident or rape victims for 10 days with the drug or with dummy pills, while they asked to describe their memories of a traumatic event that happened 10 years earlier.