Memory: Understand How It Works and Its Types

Published: 11 October, 2024 | 5'

Human beings are differentiated not only on a physical level by our appearance but also by our mind and behaviour, which are largely shaped by what we learn and remember. In this, our memory plays an essential role in our daily lives, as it is responsible for receiving and processing the stimuli we encounter and storing the information deemed relevant to construct our memories.

What is memory?

“Memory is the diary that we all carry around with us” Oscar Wilde.

This quote fits the classical definition of memory, which is the capacity to acquire, store or replenish information or lived experiences that enter our nervous system through some sensory route. Moreover, memory is associated with knowledge and consciousness, enabling us to have criteria for acting and/or adapting when necessary.

How does memory work?

Memory, while a basic function, is complex and heterogeneous. Several regions of the central nervous system are involved in the memory process, with a strong association to the hypothalamus, whose primary role is the consolidation of memory and learning.

Cognitive processes of memory

Its functioning is defined by a series of processes or stages that must be carried out in an orderly manner, through different brain structures such as the cerebellum and the hippocampus.

The neurotransmitter that plays a key role in this “memorisation” process is acetylcholine.

Neurons and synapses: Their role in information retention

The memorisation process depends on the type of information, the organisation of it, the storage capacity and persistence, as well as the brain areas involved. Memory translates into learning, and both are related to motivation, attention, communication and affection.

In this, neurons are a key element for the nervous system to transmit and coordinate information to different areas of the body. They have the ability to communicate precisely, quickly, and over long distances with other cells through nerve impulses.

How long do our memories last?

Memory is the primary axis for learning and recalling. Memories can last for minutes or indefinitely depending on the type of memory processing it undergoes. Let's explore what types of memory exist and how they function.

Types of memory

Memory is classified into two main areas, based on whether it is associated with time (short-term memory and long-term memory) or the nature of the recollection (declarative memory and non-declarative memory).

Short-term memory

This type is also referred to as immediate or operational memory. It is the capacity to retain an experience in the mind for a few seconds. It is closely linked to sensory experiences of sight, hearing, and touch.

This type of memory requires continuous repetition of the stimulus that produced it, and allows us to carry out basic and immediate functions, for example, remembering a phone number when it has been dictated to you.

Long-term memory

This type of memory is the system by which information is stored, initially inactive, but can be retrieved by the person as needed.⁶

Examples of this include recalling dates, names, people, images, etc.

Within this type of memory is where the learning process occurs, making its development very complex.

It is divided into two subtypes:

Declarative or explicit memory: this is known as the capacity to bring to consciousness specific facts or episodes from our lives (it is the “what”). This subtype is referred to as “everyday memory” and has a high storage limit. It includes conscious memories about places, objects, events, etc.
Non-declarative or implicit memory: this type of memory does not involve conscious recollection (it is the “how”), and includes previous experiences that help us perform a task “automatically” (priming). This type of memory refers to acquired habits and skills.

Phases of memory

For the new information we receive to remain in our brain and be retrievable, different phases of memory must be completed:

Recording and encoding: this is the moment of transforming the information we receive through sensory channels into another type of significant information that our memory systems can assimilate. Its details are analysed to process it depending on its meaning (if it is a sound, what it looks like, etc.).
Storage and consolidation: this is the long-term maintenance of information. Details that attract our attention move to short-term memory and, if the information is adequately processed with meaning, it moves to long-term memory. When we connect new information with existing memories or knowledge, the brain adds meaning and creates associations to make it easier for us to retrieve it in the future.
Retrieval: this is when the brain retrieves the information that has been stored. There are two ways through which we can retrieve information: by evocation (recalling the date of a birthday, for example) or by recognition by associating other ideas to retrieve a piece of data.

Memory throughout life

As we age from our adult stage onwards, our brain function gradually decreases. This means our mind will require more effort to memorise data and also to retrieve memories.

Changes in memory with age

Consequently, it is common to experience lapses in daily tasks, although if these become very frequent or are accompanied by disorientation or start to impede the completion of daily activities, it could indicate some type of memory loss. This age-related memory decline is gradual and can result in a decrease in memory-related tasks of up to 50% or more in advanced ages.

Memory losses related to age are more significant in some memory recall tasks, for example, for recalling the context of a current situation, regarding prospective memory, which relates to remembering to perform an action in the near future, but also in tasks requiring working memory, such as maintaining information in mind while carrying out that task or others that require attention.

How to maintain healthy memory in old age

The areas involved in the normal functioning of memory require nutrients to carry out their function. When these nutrients, such as vitamins C and E, along with those from group B, Omegas, and Choline, are not found in necessary amounts, alterations in brain function may occur.

Maintaining memory function is also possible, alongside a proper diet, by engaging in mental exercises that help strengthen the brain and maintain cognitive function.

How to improve memory

Along with a balanced diet and a healthy lifestyle, memory can be improved by implementing a series of habits in daily life.

Engaging in games that involve attention and memorisation (cards, puzzles, word searches, etc.).
Recalling events at the end of the day and trying to remember details.
Utilising memory techniques in new learning processes (chunking, diagrams, recordings, flashcards…).

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References

Content reviewed by specialists in the Scientific Information area of MARNYS. This article is informative and does not replace consultation with a specialist.