Episodic memory: definition and associated parts of the brain

This mental capacity is in charge of storing memories related to our experiences.

Often, when we talk about what we remember or fail to remember, we are not referring to general knowledge about the world, but about 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 the memories of our lives is episodic memory, and our brain has a system of episodic memory.and our brain has a system of nerve cells specialized in keeping it working, which produces curious phenomena. Next we will see what are the characteristics of this mental capacity.

What is episodic memory?

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

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

Thus, episodic memory is composed of data related to a place and a moment located at some point in our past, regardless of whether these memories are more precise or more blurred.

On the other hand, and contrary to what was advocated for decades by psychological currents related to psychoanalysis, these memories are almost always conscious, 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 later, although in no case do they return in detail or through a cathartic phase; the case of false memories instilled by another person is different, since they do not correspond to something that really happened.

Distinguishing it from emotional memory

It should be noted that episodic memory overlaps a lot with another type of memory that, although it works together with the first one, is governed by different logics: emotional memory.

This set of mental processes is in charge of emotional imprint linked to past experiences, i.e., something that cannot beThis set of mental processes is responsible for leaving an emotional trace linked to past experiences, i.e., 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, 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 experienced in that place, but we cannot convey emotions in such a direct way, only an approximation.

In short, emotional memory is not part of the category called "declarative memory", composed of semantic and episodic memory, and therefore is not composed 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 the one located in the temporal lobes.

The hippocampi (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 pertaining to the declarative memoryand then allow them to migrate to other areas of the brain, spread over almost the entire cerebral cortex, where they are "stored" (especially important is the role of the prefrontal cortex).

In comparison, for example, emotional memory depends much more on another pair of structures known as the amygdalae, and less on the hippocampi. Thus, people with damaged hippocampi may remember very little about their life, people with damaged hippocampi may remember very little about their lives and yet preserve emotional responses to certain stimuli linked to their past: a house, a song, etc.

Disorders that impair it

As episodic memory memories are spread over a large part of the brain, there are many pathologies and types of accidents capable of damaging it. In practice, it is dementias that are the most damaging to this mental capacity (along with the other types of memory). The case of Alzheimer's disease is well known precisely because autobiographical memories are lost as the pathology progresses.

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