The limits and failures of human memory

Not remembering if we have locked the car, going to get the keys or the mobile phone and having it in hand, not remembering where we have parked, and, of course, forgetting what we were going to say. They are everyday situations and in a way funny in which memory is revealed against us.

All these events make the person who experiences them wonder if they have a poor memory or are unintelligent. Even the most hypochondriac will consider going to the doctor for an Alzheimer's diagnosis.

But there are reasons to remain calm; These experiences do not show intellectual deficits or signs of neurodegenerative diseases, but rather it is a common psychological phenomenon that is due to the limits of our short-term memory.

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Have I locked the car? Short-term memory and its failures

Remember that short-term memory is one that allows us to interact with the present environment, since thanks to it a small amount of information is actively kept in the mind, so that it is immediately available, at least, for a short period of time.

When we have a conversation, do mathematical calculations or talk to ourselves, we are making direct use of this memory. Nevertheless, this memory is not perfect, quite the opposite.

The magic number seven

The psychologist George A. Miller he was the first to investigate these phenomena, and published an essay called "The magic number seven, plus or minus two" in which reflects the limits of our ability to process information that we find within the ranges of short-term memory (MCP). According to Miller, short-term memory has a limited storage capacity, which is between 5 and 9, that is, 7 plus or minus two. It is a biological limitation posed by our nervous system.

This means that when we retain 7 units of information in the present moment, we are not able to perceive what lies beyond of these "data packets" since all external stimuli do not have space to enter our memory at that moment in concrete.

The role of attention

Attention It is the psychological process that goes hand in hand with short-term memory, which is also highly limited. Miller clarified that it is possible to increase the number of items a person processes if what they perceive is a matter of importance and value to the individual. However, if it is not of interest to you, and it is already occupying the space, it will not be stored in your memory.

This explains that although we are occupying the full capacity of our short-term memory, if we perceive (even unconsciously) a spider in front of us, all our attentional resources will be directed to her and not to our thinking. Herein lies the functionality of this memory being limited, at times when man fought for his survival with other species, those threatening stimuli could not dispense with this scarce space in the memory.

Conclusions and reflections

Perhaps now you understand why many times you do not hear someone who has been talking to you for three minutes. Surely, what you had in your head while this person was talking to you, occupied those 7 plus minus two packets of information that you are able to retain and, evidently, your own affairs were much more important to you than what that person was to you counting.

We can also raise the situation that we initially commented on the question of whether the car is closed or not. When we get out of the car, we usually do it in a hurry and thinking about everything we have to do after parking. That is why at the time of closing the car our short-term memory is completely full of information and even if we have closed the car of unconsciously and automatically (since it is a very routine action), as our conscience is occupied, for us it is as if we had not lived it.

Something similar happens in all those situations in which the number 7 puts on the table, once again, that the human being is not perfect, but prey to his limited psychological processes.