Have you ever had a traumatic experience you wanted to forget? That embarrassing time you peed your pants or that horrible breakup you can’t seem to get over? Sure, we all have; this desire to forget our troubles is often displayed in our woeful imagination and in sci-fi films. A prime example is in my favorite movie of all time: Eternal Sunshine of the Spotless Mind. Here’s a quick, almost spoiler-free synopsis: Two people who were formerly in a relationship break up and erase their memories of each other.
In this film, people purchased a service of having scientists erase their memories of a person for them. Customers would bring all items associated with that person they wanted to forget, react to each item and the memories each item triggered, and got hooked up to a device positioned on one’s head. The scientists created a brain map of targeted events to forget and erased in reverse chronological order from most recent memories to older memories, perhaps to start erasing the clearest memories to the vaguest memories.
Before I can get into the philosophical tidbits of whether or not forgetting one’s past is beneficial, let me introduce the fascinating progress current researchers have made to make the option to forget things possible.
As of now, there is not much scientific progress towards purposely forgetting things, as running experiments can be difficult. Memories are subjective, and two different people can often remember the same event differently because the two people may be analyzing the event in a different perspective or focusing on different aspects of the event. For example, in an event of a car crash, one person in a car crash may remember how their own car gets crushed, but a bystander may focus more generally on how both cars got destroyed.
One step toward learning to forget is the Think – No Think Paradigm, where one can repeatedly prevent oneself from thinking about a memory to eventually forget it. However, this method is not a surefire way because of the ironic process theory. A common example is how if someone said to not think about a polar bear, you would probably think of a polar bear, no matter how hard you try to block out the thought. One could instead try distracting oneself with other thoughts rather than the desired thought to be forgotten.
A 2012 study in The Journal of Neuroscience found that subjects forgot more words that they purposely tried to forget than words they tried to remember. This shows how humans can control what they forget to an extent. Researchers used fMRI tests to discover that words that subjects tried to remember increased blood flow to the hippocampus, a brain region where short-term memories convert into long-term memories. On the other hand, words that subjects tried to forget show little to no activity in the hippocampus. Instead, when trying to forget words, the dorsolateral prefrontal cortex (DLPFC) showed more blood flow/brain activity, so this can lead to scientists researching the DLPFC more in its related functions with active forgetting.
The 2012 study still does not provide enough evidence into the nature of forgetting though, as the study only used a small sample size of 18 people, and forgetting words is not the same as forgetting entire memories.
Another way to conduct research on actively forgetting memories is pinpointing and analyzing genes or proteins associated with active forgetting. Some genes of interest are arc, which helps form long-term memories, and musashi, which reshapes the neural networks or paths that neurons use to transmit information.
A similar phenomenon to forgetting memories is a repressed memory. However, the definition of a repressed memory means that the memory is still subconsciously there, but on the surface, a person may not be aware of it. Through Freudian psychoanalytic therapy, a repressed memory can resurface; however, many modern psychologists discredit the legitimacy of repressed memories and are rather afraid that psychoanalytic therapy can cause patients to remember false memories of traumatic experiences like abuse.
Amnesia is also a condition of forgetting memories, such as dissociative amnesia, which the DSM-V, defines as “the inability to recall autobiographical information.” Amnesia can be general like forgetting one’s identity, selective like forgetting an aspect of an event, or more localized like forgetting a specific event or time. However, amnesia also implies that these memories are only temporarily forgotten, not permanently forgotten, as some people wish.
Right now, we don’t have the technology to completely forget a memory, but techniques like distracting oneself from the memory can decrease the detail and emotion of the memory.
References and Footnotes:
(4) American Psychiatric Association. (2013). Diagnostic and statistical manual of mental disorders (5th ed.). Arlington, VA: American Psychiatric Publishing.