“Brainwashing” is a term usually used to describe the instilling of beliefs or attitudes into someone’s brain, which in general contradict that person’s own beliefs and their system of values.

However, you can now use the term to mean removing memories or principles from one’s brain, as scientists have managed to achieve just that. The procedure has only been successfully tested in rats so far. To be more exact, frightening memories were permanently erased from the brains of the studied mice. The obliteration was achieved by artificially enhancing the production of a certain enzyme, which selectively “deletes” memories from the brains of animals.

The enzyme artificially manipulated is also present in the human brain – it is calcium/calmodulin kinase II (CaMKII). This groundbreaking progress is just a small step towards the development of a drug capable to help those struggling with post-traumatic stress disorder.

When dealing with the mice, the scientists tested the enzyme’s effects in a Pavlovian experiment. The mice were trained to fear a cage and a tone, associating them with receiving an electric shock. After some time, mice that weren’t touched by the enzyme enhancement were placed in a cage. The result was the one expected – the mice displayed signs of fear. The mice whose brains were altered to erase the frightening memories had no fear-related reaction.

The engineered mice were then again manipulated and the enzyme production was reduced. They were again placed in the stressful environment, and the mice again had not type of fearful reaction. The second part of the experiment proves that the memory-erasing process is permanent. The most astounding part of the experiment is that one can choose what memories to erase, as the mice were still afraid of cats, just not of cages. In other words, erasing a memory that produces a certain fear leaves other memories, responsible for other fears, undamaged.

So far, no method to enhance the enzyme’s productivity in humans was found, nor is there a known way to introduce more ready-made enzyme into the human brain. The procedure from “Eternal Sunshine of the Spotless Mind” has yet to become reality and not fiction, but researchers are still conducting studies and experiments that may lead to the development of a treatment in the future.