Remember the name of our most beloved pet, the first day of work and the nerves we felt, the moment we fell in love for the first time ... none of these memories that accompany us in our lives and personal growth would be possible to evoke without a very important type of memory that we will talk about today: Declarative memory.
Declarative memory, also called relational memory, is one of the two main types of long-term memory, the memory that we maintain over time. This type of memory requires an explicit expression of different data or events, that is, it is the type of memory that people use when they consciously remember certain facts or information.
The other main type of long-term memory is implicit or procedural memory, which, on the contrary, is the type of memory that we use when we perform tasks that we have very assumed but that we do not do consciously, such as acts such as driving or washing our hands. teeth every morning.
A clear example of the separation that exists between the two types of memory is found in the study of the patient H.M., whose hippocampus and amygdala were removed in 1953 to try to alleviate his epileptic seizures. Thereafter, the patient could continue to use his short-term memory, as well as create new procedural memories, but he was never able to form long-term declarative memories again. That is, H.M. could learn to ride a bike, but couldn't remember a visit from a loved one the week before.
When studying amnesic patients, the distinction between declarative memory and procedural or implicit memory becomes evident since these are adjusted to different brain processes. It is the case of being able to preserve the implicit memory, although the declarative memory is very deteriorated
Declarative memory is in turn divided into two subtypes, which can be:
It is the type of memory we use when we remember specific events that are part of our personal history. When we use episodic memory we can evoke a family event, such as that birthday of our brother or the name of our best friend from childhood. This provides us with an autobiographical story that makes us who we are..
It is the other type of declarative memory that allows us to remember general information and knowledge over time. It is the cognitive processing that allows us to remember basic things about our knowledge of the world such as which is the capital of Italy or that dogs bark to communicate. Unlike episodic memory, semantic memory is more widespread in time and accompanies us for almost our entire lives, although it can present a slow decline in old age.
There are different areas of the brain that work together for declarative memory to take place. Although without proper brain function, in general, declarative memory would not be correct, the hippocampus and prefrontal cortex are nevertheless the main regions for this cognitive process to exist.
The hippocampus is especially important for retaining episodic memory. This structure located in the temporal lobe and which is essential to retain our memories manages to record the information, as well as identify common qualities between events or events and link each new information to a specific space of our memory..
When there is loss of declarative memory, people cannot remember, especially, events stored in episodic memory. Semantic memory, in turn, can be lost over the years.
Some diseases such as Alzheimer's affect both declarative and procedural memory, although there is the ability to remember events very distant in time, while short-term memory or more recent memories largely fail. Other problems such as viruses that affect the hippocampus can lead to a decline in our declarative memory.
In 1997 a study showed how stress can also significantly influence the creation of declarative memory. When there was stress, the study participants showed a worse declarative memory than those participants who were calm. This may explain why some people with chronic stress, such as post traumatic stress disorder, have trouble keeping explicit memories..