Do you remember the movie “Total Recall”, with Arnold Schwarzenegger? In it, the main character relived a fictional life full of false memories implanted in his brain. But later, real memories begin to appear and, therefore, two realities begin to coexist contending in his brain, without him being able to discern which is false and which is true, until the memories fit with real situations like streets, buildings or people that give them validity.
This, which looks like mere science fiction happens in our brain much more often than we recognize. For us, memories “must” be fixed, since they are frames of reference that we use as human beings. The experience is one of the tools that people use most throughout our lives, with excellent results, because it allows us to calculate the future result of an action or a decision that we have taken.
Memories are modifiable
Although past experiences are milestones or references that humans use throughout our lives, studies made in the 90s, and early in the following decade, showed that memories can be modified. Going even further, it is even possible that new or false memories are implanted in the minds of individuals.
The case that better exemplifies this last one is the study realized by the doctor Kimberley Wade of the University of Warwick, in the United Kingdom, where more than 50% of the subjects that participated in the study underwent a modification of their real memories, when teaching them a trick shot where they appeared themselves enjoying a balloon ride. Interestingly, the people were convinced by the researcher that, indeed, they had made that hot air balloon trip they never made.
This seems a contradiction, because if memories help us accumulate experiences that help us when making decisions, it is assumed that these should be fixed and immutable in our mind and not subject to change.
Why does the brain modify memories?
To learn, our brain “knows” that memories are important to us, but it is also aware that external circumstances change without ceasing. Thus, the brain acts as a machine for calculating probabilities, where memories and experience play a preponderant role, but environmental circumstances are also perceived by our brain and enter into the equation.
If our brain decides that the latter are more important than memories, it will take them as a basis to determine future decisions. This is the reason why our brain can modify the memories, because sometimes, in order to remove weight from the memories we have, it modifies them with other information that at that precise moment are considered more important than the stored memories.
Unlike computers, which have been trained to think in a totally linear way, taking into account some factors and discarding others because they have little statistical weight, our brain is not linear, but is readjusted in a few seconds and takes into account details which are only important if several environmental factors are aligned at a certain time and place. The brain knows something that computers ignore and that the details (of whatever kind) must condition our responses to be as optimal as possible, even if the statistics do not support them.
Our brain is deliberately mistaken
The mind of the human being usually commits “errors”, but these have a useful objective. Next, an example presented by the expert in cognitive neuroscience of the University of Edinburgh, in the United Kingdom, Sergio Della Sala: Imagine that you are in the middle of the jungle and, suddenly, you realize that there is a movement in the grass. Most likely, any person is terrified and flee in terror, because there is a possibility that a tiger is approaching.
Instead, a computer would perform calculations and come to infer that the cause of such movement, in 99% of cases, is the wind. If human beings act like computers, in the opportunity (1 out of 100) in which, indeed, there was a tiger, we would be eaten. For this reason, our brain is “designed” to make calculation errors 99 times, in order to save us from the beast. In fact, Della Sala adds that false memories are signs that a brain is healthy.