Technology to manipulate memories is a reality
A research carried out at the University of California almost a year ago and just recently published in the scientific journal Nature has revealed that it is possible to selectively remove and reactivate a memory by creating a stimulus that strengthens or weakens the nerve cells (synaptic connections).
In the past it was believed that memories were stored in a cell and that, for instance, a certain memory of a person would come back if that particular cell was stimulated. However, this research, lead by Dr. Roberto Malinow, demonstrated that memories are actually constructed as a pattern of synaptic connections and not only a single cell.
The experiment that helped to come to this conclusion consisted of stimulating the optical nerve of a genetically modified rat that was sensitive to the light and simultaneously provide an electrical shock to one of the rat's feet. Shortly after this the animal learnt to associate the stimulation of the optical nerve with pain and showed signs of fear when the optical nerve was stimulated.
In a further analysis after the experiment it was found the synaptic connections were strengthened by showing chemical changes.
In the second part of the experiment a low-frequency collection of optical pulses were applied in order to erase the rat's memory and it was found that after repeating the first part of the experiment the rats didn't with fear when the optical nerve was stimulated. Therefore, indicating that memories associated to pain were indeed erased.
Shockingly, in a third part of the experiment, a high-frequency collection of optical pulses were used on a group of rats whose memories were erased and they responded again with fear even when they were not exposed to any electrical shock.
The experiment used Optogenetics, a combination of optics and genetics, and it could be the first step to have technology in the future that could potentially manipulate memories at will, help people to erase traumatic memories or simply allow situations like the one exposed in the film Eternal Sunshine of the Spotless Mind and terrifying but true, possibly having soldiers that can't remember what fear is.