Memory Erasure in Nine Years
The plot of Nine Years hinges on experimental surgery to erase someone’s memories. This procedure is entirely fictional, but there are several real-life methods for selectively erasing a subject’s memory. These range from methods commonly used on patients to more theoretical methods. These include (in order of most to least viable) drug-induced amnesia, selective memory repression, optogenetics, actin depolymerization, and the destruction of neurons.
Drug-Induced Amnesia
Drug-Induced Amnesia is the process of using some sort of compound to prevent new memories from being created. This does not delete memories from the past, as is portrayed in fiction and as other real-life methods do, but is effective in preemptively erasing an upcoming experience. This is how Anaesthesia works, as well as other types of sedatives. This form of memory erasure has the most widespread and practical use in the medical field. Certain prescription drugs also have an amnestic side-effect1.
Selective Memory Repression
Selective Memory Repression is a process done through therapy to repress past traumatic memories. A patient will identify a memory to erase and work with a therapist to erase that memory from their mind. This practice becomes less effective for older adults than younger adults, but it has been shown that older adults can still repress memories when given more tailored strategies and instructions2. This is the most used form of retroactively erasing memories.
Optogenetics
Optogenetics is a type of gene therapy using light. This process is used to weaken the connections between neurons. When memories are formed, neurons form new connections. By weakening these connections, it is possible to erase specific memories. Optogenetics testing has been done on animals, and has recently been approved for human testing. Optogenetics can also be used to observe and record cell activity in the brain3.
Actin Depolymerization
Memories are formed and stored through a chemical process called “Actin Polymerization.” In this process, a “G-Actin” molecule reforms itself into an “F-Actin” molecule. This process is especially important in unconscious and muscle memory. If this chemical process could be reversed, it could erase specific memories. Studies in this field specifically focus on how this could help recovering drug addicts, erasing the muscle memory triggers that come from viewing drug paraphernalia4.
Neuron Destruction
The most theoretical method of memory erasure also happens to be the method closest to what is described in Nine Years. The idea is pretty much what it says on the tin: destroying neurons associated with a specific memory could be used to erase said memory. This process would (in theory) involve the use of toxins to destroy these neurons5. The problem is that the brain is incredibly complicated. There are between 62 and 94 billion (with a “b”) neurons in the human brain6, with around 60 trillion connections between them7. The worry is that destroying any of these neurons could have unwanted side effects besides just erasing memory. In order to mitigate the potential side effects, there is also an idea to “stun” the neurons using electrical currents. Neither of these have been tested, but the prospect is interesting8.
The line between science fiction and science fact may be thinner than you think. Memory erasure as portrayed in Nine Years may currently not exist, but based on research currently being done, it could just be right around the corner.
Nine Years runs January 29-31 in the BYU Black Box Theatre.
Footnotes:
1. Keenan, Erin, and Richard L. Barbano. “Drug-Induced Amnesia.” VisualDx, August 27, 2018. https://www.visualdx.com/visualdx/diagnosis/drug-induced+amnesia?diagnosisId=56262&moduleId=101.
2. Murray, Breandan D, Michael C. Anderson, and Elizabeth A. Kensinger. “Older Adults Can Suppress Unwanted Memories When Given an Appropriate Strategy.” Psychol Aging, January 19, 2015. https://pmc.ncbi.nlm.nih.gov/articles/PMC4360753/.
3. Adamczyk, Agnieszka K, and Przemysław Zawadzki. “The Memory-Modifying Potential of Optogenetics and the Need for Neuroethics.” Nanoethics, October 17, 2020. https://link.springer.com/article/10.1007/s11569-020-00377-1.
4. Young, Erica J, et al. “Selective, Retrieval-Independent Disruption of Methamphetamine-Associated Memory by Actin Depolymerization” Biol Psychiatry, September 5, 2013. https://pmc.ncbi.nlm.nih.gov/articles/PMC4023488/.
5. Chan, Jason C. K, and Jessica A. LaPaglia. “Impairing existing declarative memory in humans by disrupting reconsolidation.” Proc Natl Acad Sci U S A, May 20, 2013. https://pmc.ncbi.nlm.nih.gov/articles/PMC3677482/.
6. Goriely, Alain. “Eighty-six billion and counting: do we know the number of neurons in the human brain?” Brain, November 27, 2024. https://academic.oup.com/brain/article/148/3/689/7909879
7. Gulati, Anil. “Understanding neurogenesis in the adult human brain.” Indian J Pharmacol, November 2015. https://pmc.ncbi.nlm.nih.gov/articles/PMC4689008/.
8. Iverson, Margot. “Killing Pain by Killing Neurons.” Science, November 22, 1999. https://www.science.org/content/article/killing-pain-killing-neurons
