What is forgetting and why do we forget important things?

What did you have for dinner last night? When was the last time you cried? What did you do on the morning of April 15, 2008? How did you celebrate your third birthday? Surely you have not been able to answer all these questions. What is this type of forgetfulness due to?

Let's see what are the neuropsychological mechanisms that explain this phenomenon.

What is oblivion?

Memories are not permanent, since they are kept in a continuously changing tissue in which some neurons die and certain connections change or weaken. This means not only that we can lose the accessibility of the stored information, but also its availability in our cognitive system.

What is the difference between the two concepts? According to Endel Tulving, accessibility refers to the ease with which a stored memory can be recover at a certain time, while availability refers to the presence or not of a trace in the memory store.

Thus, an experience may seem completely lost just because a suitable recovery key has not been presented to evoke the memory. This would mean an inaccessibility of the information at the time of recovery, but not necessarily a loss of availability, so it could be recovered at another time.

Types of forgetfulness

Considering the studies carried out on memory, two types of forgetting are distinguished: intentional forgetting and incidental forgetting.. The first undertakes processes or behaviors that intentionally diminish accessibility for some purpose, while the second occurs without the intention of forgetting. This article will focus on the latter, showing some factors that encourage and diminish it.

Factors that promote incidental forgetting

Now: what factors influence when we simply forget some relevant data?

1. Pass of the time

The forgetting curve (described by Ebbinghaus), shows a logarithmic decrease in memory retention as a function of elapsed time (known as footprint decay). That is, as time passes we remember less information.

However, it is impossible to control factors such as reviewing the memory or storing new experiences, which generates interferences, being difficult to empirically demonstrate the effect of time per se.

Other factors to consider are fluctuations in context and interference.

2. Context fluctuations

When the retrieval incidental context does not match the context present during encoding, forgetting is more likely. With the passage of time the contextual changes are, in general, greater, since the world changes and so do we. An example is the case of childhood amnesia, which refers to the difficulty that most people have to remember the first years of life.

One possible cause is that children experience things very differently from the adults they become, things seem relatively larger in childhood. (However, the maturation process they are in must be taken into account, since they have not yet developed the brain as an adult).

3. Interference

Interference refers to the difficulty of retrieving similar stored traces. We are able to remember experiences that are unique and easily distinguishable more easily and for longer. Thus, sticking to routines makes life less remembered.

The interference becomes greater when the key that allowed access to the object memory footprint is associated with additional memories, due to the fact that various items compete with the objective of accessing consciousness (assumption of competition). In other words, if we store information similar to the consolidated one, it is more difficult to access it. For example, the memory of a summer. We will remember more easily the year we visited our neighbor's town (unique experience) than the summer in which We went to ours, since in the second case, going every year, it will be difficult for us to discern what specifically happened in each one.

4. Presentation of part of the keys of the set

When part of a set of items is presented, the ability to remember the remaining items in the group is weakened.

This is due to exposure to one or more competing items., which aggravates the problems we find to recover a certain objective memory. The logic, following the interference situation described above, is the following: if the presentation of some items in the set strengthens the association of those items with the key, the strengthened items will produce greater competition during the recovery of the items not presented and will damage the I remember.

For example, when we do not remember a word (we have it "on the tip of our tongue") it is not beneficial for our acquaintances offer us a wide list of terms since they will promote their accessibility, but not that of the word in question.

5. Recovery

A paradoxical characteristic of human memory is that the very act of remembering causes forgetting. Intentional retrieval of an experience has an effect on memory.

If memories are periodically retrieved, your resistance to forgetting increases. However, we must be cautious as to what is recovering, because if we recover the experience on several occasions, perhaps we are evoking the memory of what we have previously recovered (with its own context and details), and not the original situation.

This means that the more often we recall an experience, the more recall events exist in our memory. As long as the information retrieved is increasingly accurate and complete, the process will improve recall. However, if the memories are incomplete or inaccurate (due to interference made during attempts to reconstruct the event), what we remember might not be what happened originally.

For example, when selectively reviewing only some topics that are entered for an exam (due to lack of time), material that is not reworked will be damaged, especially if it is related to the reviewed.

What factors stop incidental forgetting?

Jost's Law says that if two memories are equally strong at any given time, the older one will be more durable and will be forgotten more slowly. Thus, it is widely accepted that, in principle, new strokes are more vulnerable until little by little they are recorded in memory through the consolidation process.

Types of consolidation

There are two types of consolidation: synaptic and systematic consolidation.. The first shows that the experience imprint takes time to consolidate (hours / days ...) because it requires structural changes in the synaptic connections between neurons. Thus, until they have occurred, the memory is vulnerable.

The second holds that the hippocampus is necessary for memory storage and subsequent retrieval (as it constantly reactivates the brain areas involved in the initial experience), but its contribution diminishes over time until the moment in which the cortex itself is able to recover the information. Until memory becomes independent of the hippocampus, it is more vulnerable to forgetting.

Bibliographic references:

• Baddeley, A., Eysenck, M. W., & Anderson, M. C. (2010). Memory. Alliance.