Scientists have known for some time that specific circuits in the brain react to experiences and encode those same experiences into our minds as memories. These memories are central to our identity and the narrative we construct about ourselves and the world around us.
In past experiments, neuroscientists have been able to partially transfer memories between rodents but they have never wholesale manufactured false memories—until now.
A recent study, the results of which were published in the journal Nature with the provocative title Memory formation in the absence of experience, has demonstrated for the first time the complex and stunning process by which memories can be generated inside the minds of animals and retained just as cohesively in everyday experience as natural memories.
It’s a huge discovery in the still-nascent scientific industry of “memory manipulation,” which aims to assist patients with conditions like Alzheimers and PTSD.
The paper’s abstract postulates that “memory is coded by patterns of neural activity in distinct circuits. Therefore, it should be possible to reverse engineer a memory by artificially creating these patterns of activity in the absence of a sensory experience.”
Scientists proved this hypothesis by essentially reverse engineered a memory and then exporting it. Specifically, a natural memory was created in the mind of a mouse.
In this case, it was the memory of a foot shock which was associated with an odor, the smell of cherry blossoms. The mouse learned it could avoid the shock (and the smell of cherry blossoms) by circumnavigating its direction to an adjacent chamber that triggered another odor, the smell of caraway.
The next phase of the experiment involved identifying how those scents affect the brain and manipulating that mechanism. According to the researchers, caraway originates from the chemical carvone and cherry blossom from acetophenone. Acetophenone triggers an olfactory sensory nerve cell receptor which creates a memory of the smell.
Scientists used optogenetics—a complex process of using light-sensitive proteins and implanted optic fibers to manually stimulate certain neurons—to train the mice to associate the electrical foot shock with optogenetic light. This corroborated the belief that they didn’t need to actually experience the odor to identify an association between the foot shock and the smell. That connection could be manually created.
To complete the artificially infused memory though, scientists had to go one step further and simulate the foot shock aversion too, which they did by using a virus to embed light-sensitive proteins into the ventral tegmental area (VTA) of the nerve pathways.
This, according to Scientific American author, Robert Marcone, meant, “The animals recalled the artificial memory, responding to an odor they had never encountered by avoiding a shock they had never received.”
In summation, scientists reverse engineered a memory in mouse #1 to learn the blueprint of brain circuits that created the specific memory; then they used light to “hack” brain circuits and artificially implanted that memory into mouse #2. Mouse #2 acted as if he directly recalled the foot shocks associated with smelling cherry blossoms even though he had experienced neither the foot shocks nor the scent of cherry blossoms. Scientists engineered that memory into his little mind.
The big question is whether this is possible in the significantly more complex human mind and, if so, is it ethical for scientists to tamper with human memory?
As with most major scientific advancements, the field of memory manipulation carries both great promise and great peril, existential risk and reward, that must be carefully considered and counter-balanced. Treatment of diseases like Alzheimers and other conditions like PTSD from rape or war trauma, or other mental illnesses, is incredibly tempting.
However, if the technology is wielded nefariously by corporations or governments, it could warp our reality into something beyond horrifying—something we don’t even remember.