The spotless mind? Scientists have begun testing chemicals that can 'delete' memories

Trauma could potentially be treated by erasing memories

9. In Eternal Sunshine of the Spotless Mind Jim Carrey and Kate Winslett medically erase each other from their memories (AP)

Scientists are testing chemicals that could delete and even re-write stressful or fear forming memories.

Potentially damaging memories of traumatic incidents can form memories that shape a person's life. Scientists are hoping this research could one day help form medical treatments for people suffering with post traumatic stress disorder (PTSD) or battling addictions.

To demonstrate the unreliability of memory, researchers at the University of Washington asked adult volunteers to respond to a survey about their eating or drinking habits before the age of 16. After a week, the respondents were handed an analysis of their answers that falsely stated they had been ill after drinking rum or vodka as a teenager.

One in five participants not only did not spot that a lie had been inserted, but also recalled false memories about the 'incident' and said they were less keen on drinking the alcohol since being sick from it.

Studies such as this can help to look at other possible treatments for mental health issues, according to Popular Science.

PTSD and addiction disorders hang onto memories which can trigger problematic behaviours, they report, such as cravings induced just by seeing drug paraphernalia or the feeling of terrifying fear from hearing loud noises.

Studies have since discovered chemical compounds that have been effective in subduing and deleting memories of mice, leading researchers to wonder if the same compounds would be effective on humans.

In June, research by Emory University in Georgia found a drug used to treat PTSD, SR-8993, actually worked to prevent fear memories forming in mice.

The rodents were strapped to a wooden board for two hours where they were unable to move. The stress of the experience created a heightened sense of fear like that experienced by people with PTSD, but mice given SR-8993 were less likely to feel an increased sense of fear after the event.

In a separate study, researchers found the drug Latrunculin A could 'erase' memories of an event days after it occurred. Mice were trained to consume methamphetamine in a visually distinctive sensory room filled with various scents. Rodents that were injected with Latrunculin A two days later did not seek out the methamphetamine when they were returned to the same environment, but the other rodents did.

In July, a team at the Massachusetts Institute of Technology conducted a study that found the individual memories of mice leave recognisable molecular signatures in the brain’s hippocampus region. The team genetically engineered a mouse so that its hippocampal cells would be tagged with a protein when activated which the researchers could switch on later. The mouse was placed in an unfamiliar cage for a day, before being moved into a noticeably different cage which was scented and had black walls.

At the same time, they gave it an uncomfortable shock and switched on the tagging protein to briefly activate cells that had been active in the old cage. When they put the mouse back in the old cage, it froze as if afraid, suggesting a false memory had been 'shocked' there.

Scientists are now hoping that continued research will explain how the brain's neurons encode each memory and thus provide better treatments for people plagued by traumatic memories.