Memories of a particularly difficult period or frightening event can haunt us for years. They can crop up in dreams and can be triggered at seemingly random times. But what if you could erase them for good?
The idea sounds like science fiction movie, and was actually the core concept of Charlie Kaufman’s movie, Eternal Sunshine of the Spotless Mind, where two estranged lovers have their memories of each other deleted. However, researchers at the University of Toronto believe such a procedure could soon be a reality.
Always on your mind
The work is aimed at treating people suffering from post-traumatic stress disorder or PTSD: those who have involved in military combat, experienced atrocities, suffered a serous accident, been abused, held hostage and so on. Eradicating those specific memories could be a life-changing operation for many.
Memory is a brain-wide system
Scientists used to believe that memories were stored in specific sections of the brain – like folders in a filing cabinet – but have since found that memories are more widely distributed throughout. What might seem like a single memory is a complex construction, recreated from a number of different areas. When you remember your pet dog, its face will be from one set of brain cells, it’s sound from another; its smell from an other…
As you go through life, different stimuli send signals to certain parts of the brain. If a signal between brain cells – or neurons – is strong enough, new connections are formed at point called a synapse. Each neuron can form more than 10,000 of these, providing a normal brain with around 100 trillion synapses.
These synaptic connections are constantly changing as you experience new events, but as you repeat actions – like learning to read or listening to the same piece of music – the same signals keep firing, strengthening the synapse and forming a network of neurons.
The researchers discovered that it only takes a handful of neurons to create a bad or fearful memory, and it was possible to highlight those neurons by the over-production of a specific protein in the brain. The genetic removal of the targeted neurons is enough to disrupt the memory without affecting other memories.
Taking the pain away
If the procedure proves successful, it would be hugely beneficial to those suffering from PTSD, whose painful memories prevent them from living a normal everyday life. But it could also be used to help people with drug addiction, by removing the emotional memories linked with the drug taking.
However there are certain ethical considerations, as the research team leader,Professor Sheena Josselyn, admitted: “There could be potential downsides, especially when applied to people who would like to get rid of a bad memory such as a messy break up,” she said. “We all learn from our mistakes. If we erase the memory of our mistakes, what is to keep us from repeating them?”