By Andrea Flores Esparza
One can likely recall vivid memories of important events that have happened to them throughout their life. In some cases, people affirm specific sensory details of the event, including visuals, sounds and smells. However, the complexity of the memory mechanisms of the human brain has raised ambiguities of whether these recollections can be validated as being the “absolute truth”. In essence, the recollection of memory is based on the coordinated firing of neuron ensembles that enable humans to remember certain events, feelings or skills.
Memory formation is achieved through synaptic plasticity, referring to the constant modification of connections between other neurons and the strength of these (University of Queensland, n.d.). The strength of the neuronal connections is dependent on the regularity in which they are used. For instance, studying for a test weeks before will strengthen the connections between those neurons facilitating the remembrance of information on the given day. However, if the content for the test is only revisited an hour before it would be very unlikely the individual will have the ability to recall the information in great detail. Moreover, scientific evidence has suggested that neurogenesis—the formation of new neurons—occurring in the hippocampus can also improve the formation of memories (University of Queensland, n.d.). It is important to note that there are various different forms of memory, which are stored across the interconnected regions of the brain. The neuronal ensembles related to episodic events and semantic information, termed explicit memories, are generally located in the hippocampus, the neocortex and the amygdala whilst implicit memories, referring to those that require a motor neuronal skill and emotions, are located on the basal ganglia and cerebellum (University of Queensland, n.d.).
Human beings heavily rely on their memory not only for the recollection of semantic information, but also to guide our every-day behaviour. Nonetheless, neuroscientists have found evidence suggesting that our memories are not fixed, but rather malleable and to a greater extent unreliable (Brewin, Andrews & Mickes). Although oneself could declare they are stating the full truth, the reality is that this memory is likely to be distorted. More strikingly, studies have found that false memories can be implanted into people’s head even though they had never experienced it. For example, in Shaw’s and Porter’s experiment conducted in 2015, they subjected 60 students to a “modified familial-informant false-narrative paradigm” with the aim to convince them that they had committed a crime. Surprisingly, at the end of the experiment 70% of the participants were able to recall false memories of them committing a crime (Shaw & Porter, 2015). There are other ways in which the human memory system can potentially be altered; by presenting subjects with misleading information known as the “misinformation effect” as well as through the passage of time. Another fascinating example being one based on the 9/11 terrorist attack. Citizens of New York City were asked to recall the moment where they heard the news of what had happened weeks, a year and three years after the event. After one year, the recollection of events had changed in 37% of the subjects, and 43% after three years. However, participants were confident on the accuracy of their memory (Lacy & Stark, 2020).
The unreliability of memory has implications on society too, one of the most distressing scenarios being the court of law. For 100 years, there has been a debate on whether witnesses should count as a source of evidence in for the incrimination of a suspect. Numerous juridical systems throughout the world rely on witnesses that can provide a “truthful” insight on the crime that is being considered. However, this phenomenon raises the question of whether an individual’s fate should be based on someone else’s memory. As mentioned above, a witness’ memory could be altered through various different ways and hence could potentially be devasted for the suspect. Moreover, it is important to note that high levels of stress could heavily deteriorate the formation of memories; suggesting that in the case of a stressful situation, the witnesses may not have been able to establish concrete neurological connections (Lacy & Stark, 2020). On the other hand, understanding this phenomenon can provide significant improvements in the medical procedures of mental health illnesses. Understanding and perfecting the mechanisms in which the human mind can alter memory can help psychologists to distort their patient’s traumatic memories in illnesses including depression, post-traumatic stress disorder (PTSD) and anxiety. Amy Milton explores the possibility of editing memories in the TedTalk: “Can we edit memories?”. In Milton’s talk they mention that the ability to “edit” a patient’s memory requires specific conditions that enable them to access the memory and manipulate it. This can be used in clinical scenarios to “destroy […] maladaptive fear memories” that are causing the deterioration of an individual’s quality of life (Milton, A). She explored the promising results of a study that found that Propranolol, a drug used to regulate human blood pressure, was able to reconsolidate the rats’ fear memories, suggesting that it can be used to modify or even delete traumatic memories. However, for this to occur, the patients would have to be in specific conditions that allow medical intervention in memory-destroying treatments.
In summary, the complexity of the human brain has fascinated and mesmerised scientists throughout time. Past and current research studies have aimed to deepen the overall understanding of the neurological mechanisms that allow human beings to have the ability to store and recall past memories including those that are episodic and semantic as well as those that are based on motor memory. The importance of memory arises with the fact that the establishment of connections between neurons are able to guide and form us as unique individuals. Understanding the implications of the unreliability of memories is essential to increase the livelihood of the population as it will avoid false incriminations whilst potentially curing mental health illnesses.
Brewin, C.R., Andrews, B. and Mickes, L., 2020. Ezproxy Login Page. [online] Journals-sagepub-com.iclibezp1.cc.ic.ac.uk. Available at: <https://journals-sagepub-com.iclibezp1.cc.ic.ac.uk/doi/full/10.1177/0963721419898122> [Accessed 19 November 2020].
Lacy, J. and Stark, C., 2020. The Neuroscience Of Memory: Implications For The Courtroom. [online] Semanticscholar.org. Available at: <https://www.semanticscholar.org/paper/The-neuroscience-of-memory%3A-implications-for-the-Lacy-Stark/5ecf43b52906183017d5cd620ef4d490e20e9739> [Accessed 19 November 2020].
Milton, A., 2020. Can We Edit Memories?. [online] Ted.com. Available at: <https://www.ted.com/talks/amy_milton_can_we_edit_memories/up-next#t-535602> [Accessed 19 November 2020].
Shaw, J. and Porter, S., 2020. Ezproxy Login Page. [online] Journals-sagepub-com.iclibezp1.cc.ic.ac.uk. Available at: <https://journals-sagepub-com.iclibezp1.cc.ic.ac.uk/doi/full/10.1177/0956797614562862> [Accessed 19 November 2020].
University of Queensland. How Are Memories Formed? [online] Qbi.uq.edu.au. Available at: <https://qbi.uq.edu.au/brain-basics/memory/how-are-memories-formed> [Accessed 19 November 2020].
University of Queensland (2). Where Are Memories Stored In The Brain?. [online] Available at: <https://qbi.uq.edu.au/brain-basics/memory/where-are-memories-stored> [Accessed 19 November 2020].