Opinion – Luciano Melo: Crashes in our memory create avenues for fake news

Let’s start with a mental exercise. Recall a conversation in which you and friends recalled past events. Take back a moment of disagreement, when acquaintances confronted different versions of a given fact. If everything went honestly, you are already remembering, as the discussion continued, a new narrative slowly took shape. Finally, an updated version containing elements from previous plots, associated with new data recalled in the heat of prose. Here I give an example of memory convergence, a dynamic process of memory reconstruction.

A dialogue like this is only possible because of the fluidity of our memory. This malleability serves a limited brain, incapable of fixing all the information. However, human memory transcends this obstacle and imposes itself as a great adaptive force for our survival.

The learning consolidation process is all dynamic. First, memories are encoded and stored in a specific brain region and its surroundings, the hippocampus. These locations bring together the information that makes up memory—what happened, with whom, when, and where. The newly encoded memory is rich in detail and its components interconnect harmoniously.

Over time, the memory loses its richness, the memory becomes more narrative, less dependent on the hippocampus. At this stage, memories diffusely occupy brain areas. It will be possible to recall a particular feature of a past event, only if its reminiscences are still stored in the hippocampus. For our understanding of the present, recalling details of recent events is more relevant than recalling ancient minutiae.

Nor is it so useful to remember the smallest aspects of a single episode, but rather the patterns that are repeated in different events. Our memory systems make memories of details yield to generalizations. We remember what is important and repetitive, while forgetting what is irrelevant. We add up past experiences to predict what will happen. News is stored in established memory schemes, rather than being stored independently.

However, if we use a memory schema a lot, the brain starts referring to it frequently. In this way, new knowledge will be associated with this one and not with possibly more adequate ones. A dominant schema can dominate the entire learning consolidation mechanism.

This makes it easier for us to learn information that is in agreement with our established knowledge or with our already ingrained beliefs. But it also carries the risk of turning any data into affirmative proof of our convictions.

Incomplete or wrong information can turn the tricky clue for the brain to create false memories while reminiscing about old situations and clumsily organizing our memories. A false memory arises thanks to the reconstructive nature of the mental mechanisms of recall, especially when we recall while learning something.

A classic example: a large number of people were surprised by the death of Nelson Mandela in 2013. For them, the leader had died decades ago, while he was still in prison. These people were said to vividly recall televised funeral scenes. These false memories were probably consolidated during unpretentious conversations fused with memories of the death of another South African activist, Steve Biko.

The spread of disinformation, as occurs on fake news sites, has the potential to distort memories and therefore distort the understanding of history. Extensively repeated factoids tend to appear reliable, especially when targeted at like-minded groups of people.

Misleading information, when it reaffirms convictions and allays doubts, strengthens the cohesion of these groups by promoting the convergence of memories. Memory convergence is not always aimed at the most accurate version. Your priority is to bring conformity to the people pool.

Maybe I implanted a false memory in you. Because it’s possible that you’ve never had a conversation like the one portrayed in the first paragraph and still had the memory. But if you did have a similar conversation, what guarantees that the last version of the remembered event was in fact the most accurate?

So vulnerable to errors, we must check the information and not validate opinions based in a vacuum.

References:
1. How Facebook, fake news and friends are warping your memory | Nature [Internet]. [cited 2021 Dec 9]. Available from: https://www.nature.com/articles/543168a

2. How to optimize knowledge construction in the brain | npj Science of Learning [Internet]. [cited 2021 Dec 9]. Available from: https://www.nature.com/articles/s41539-020-0064-y

3. Murphy G, Murray E, Gough D. Attitudes towards feminism predict susceptibility to feminism-related fake news. Appl Cogn Psychol. 2021;35(5):1182–92.

4. Greene CM, Murphy G. Quantifying the effects of fake news on behavior: Evidence from a study of COVID-19 misinformation. J Exp Psychol Appl. 2021;No Pagination Specified-No Pagination Specified.

5. Josselyn SA, Tonegawa S. Memory engrams: Recalling the past and imagining the future. Science. 2020 Jan 3;367(6473):eaaw4325.