Many times, when we talk about what we remember or do not remember, we are referring not to general knowledge about the world, but to ourselves and our experiences. In this case we are the main experts, and we cannot talk about having more or less culture because we know more or less details about our life, since we decide which parts are relevant and which are not.

This type of memory based on memories of our lives is episodic memory , and our brain has a system of nerve cells specialized in keeping it functioning, which produces curious phenomena. We will now see what the characteristics of this mental capacity are.

What is episodic memory?

The so-called episodic memory is the type of memory in charge of processing and storing the autobiographical information of each one and, specifically, that facet of one’s own experiences that can be expressed in words or images. In other words, it is the set of higher psychological processes that create narrative memories about one’s own life, that which one has gone through.

Childhood memories are the typical example of declarative memory, since they are composed of small stories, anecdotes that one has experienced in the first person and are linked to information about contexts through which one has passed .

Thus, the episodic memory is composed of data relating to a place and a moment located somewhere in our past, regardless of whether these memories are more precise or more blurred.

On the other hand, and contrary to what has been defended for decades by psychological currents related to psychoanalysis, these memories are almost always conscious (and, therefore, limited), although sometimes, if the trace they left is very weak, they may disappear for a while to reappear timidly afterwards, although in no case do they return in great detail or through a cathartic phase; the case of false memories inculcated by another person is different, since they do not correspond to something that really happened.

Distinguishing it from emotional memory

We must take into account that episodic memory overlaps a lot with another type of memory that, despite working together with the first one, is governed by different logics: emotional memory.

This set of mental processes is responsible for leaving an emotional imprint linked to past experiences , that is, something that cannot be expressed in words.

For example, when we smell something that reminds us of our youth in a small town, that information goes beyond words and what can be narrated and transmitted to others; after all, it is composed of subjective emotions. We can tell stories about the things we live in that place, but we cannot convey emotions in such a direct way, just an approximation.

In short, emotional memory is not part of the category called “declarative memory”, which is made up of semantics and episodes, and therefore is not made up of concepts.

Parts of the brain involved

Possibly the two most relevant brain structures in the functioning of episodic memory are the hippocampus and the cerebral cortex, especially that found in the temporal lobes.

The seahorses (as there is one in each hemisphere of the brain) are structures located on the inner side of the temporal lobes, and are believed to act as a “directory” of information. That is, they encode memories belonging to declarative memory , and then they allow these to migrate to other areas of the brain, distributed throughout almost the entire cerebral cortex, which is where they are “stored” (the role of the prefrontal cortex is especially important).

In comparison, for example, emotional memory depends much more on another pair of structures known as tonsils, and not so much on seahorses. Thus, people with damaged seahorses can remember very little about their life and yet preserve emotional responses to certain stimuli linked to their past: a house, a song, etc.

Disorders that damage it

Since the memories of the episodic memory are spread over a large part of the brain, there are many pathologies and types of accidents that can damage it. In practice, it is the dementias that are the ones that are most fattened by wearing out this mental capacity (along with the other types of memory). The case of Alzheimer’s disease is known precisely because autobiographical memories are lost as the pathology advances.

Other diseases capable of damaging it are brain tumors, ischemia in the brain, encephalitis in some of its varieties and a large number of serious neurological disorders, such as Korsakoff’s syndrome or spongiform encephalopathies that pierce the tissues of the nervous system.