False memories have been implanted into mice. A team was able to make the mice wrongly associate a benign environment with a previous unpleasant experience from different surroundings. http://www.bbc.co.uk/news/science-environment-23447600 The brains of genetically engineered mice were implanted with optic fibres in order to deliver pulses of light to their brain. Known as optogenetics, this technique is able to make individual neurons respond to light.
Just like in mice, our memories are stored in collections of cells, and when events are recalled we reconstruct parts of these cells – almost like re-assembling small pieces of a puzzle.
It has been well documented that human memory is highly unreliable, first highlighted by a study on eyewitness testimonies in the 70s. Simple changes in how a question was asked could influence the memory a witness had of an event such as a car crash.
when mice recalled a false memory, it was indistinguishable from the real memory in the way it drove a fear response in the memory forming cells of a mouse’s brain.
The mouse is the closest animal scientists can easily use to analyse the brain, as though simpler, its structure and basic circuitry is very similar to the human brain.
“If you want to grab a specific memory you have to get down into the cell level. Every time we think we remember something, we could also be making changes to that memory – sometimes we realise sometimes we don’t,” said Xu Liu of the RIKEN-MIT Center for Neural Circuit Genetics.
“Humans are highly imaginative animals. Just like our mice, an aversive or appetitive event could be associated with a past experience one may happen to have in mind at that moment, hence a false memory is formed.”
The study was an “impressive example” of creating a fearful response in an environment where nothing fearful happened.
A possibility in the future is erasing memories said Rosamund Langston from Dundee University.
“Episodic memories – such as those for traumatic experiences – are distributed in neurons throughout the brain, and in order to make memory erasure a safe and useful tool, we must understand how the different components of each memory are put together.
“You may want to erase someone’s memory for a traumatic event that happened in their home, but you certainly do not want to erase their memory for how to find their way around their home.”