The Stages of Memory Consolidation

This process of memory consolidation takes place in three stages. For example, learning a song and being able to sing it without listening to it seems simple. However, it isn't.

Memory consolidation is a process that goes beyond retention. Many memories are untouchable, while many others fade with time. Emotions play a leading role in most of them, and the stronger the emotional link, the easier it’ll be for them to remain in your mind.

One can define memories by events, facts, figures, dates, and lessons that you once experienced and incorporated into your memory. What processes are involved in consolidation? Why are some memories more important than others?

The stages of memory consolidation

To answer the above questions, it’s necessary to establish that memories happen in three stages. Currently, there’s a general consensus that establishes that remembering is a cognitive process one can divide into sub-processes. Each of these stages has its own characteristics and functioning:

• Recording: encoding and storage.
• Retention or conservation.
• Retrieval.

First stage: recording

This is the first step in memory consolidation. There must be information for the nervous system to receive and process.

However, this step isn’t simply about the reception of a stimulus but about processing it into temporary storage. Moreover, this step constitutes the first filter for which attention is important.

The importance of attention

Human beings have limitations at the level of processing and simply can’t register all stimuli effectively. For this reason, you concentrate on the register of the words when you read a book, and not on the rest of the stimuli around you.

The register may present in different modalities, depending on the channel through which you receive it. The following stand out among the main ones:

• Visual. Perhaps the most developed sense and also the most used when interacting with the environment.
• Auditory. The registration and processing of sounds are crucial in the process of language acquisition.
• Gustatory. The memories of your favorite and least favorite foods registered by the taste buds.
• Olfactory. This sense is closely linked to taste, which evokes emotional content in many situations.
• Tactile. Being able to recall an action at a tactile level requires its prior registration.

Second stage: memory retention or consolidation

Once a piece of information registers, it requires storage. Thus, it must have a deep meaning in order for it to be relevant.

This is a transition process between working memory or short-term memory (sensory in nature) and long-term memory. For this process to be effective and for the information to acquire a significant meaning, it must:

• Have an association with known elements (often other memories). This step involves the connection of new stimuli with others already processed and stored.
• Analysis. Reviewing and adding details to the stimulus is also a way to make it relevant.
• Repetition. This is a crucial step for consolidation. The more times you repeat a piece of information, the better the encoding and storage of its details.
• Emotional content. Limbic activation is fundamental in the consolidation of memories. Thus, you’ll be more predisposed to perceive the details of emotionally relevant events.

Storage isn’t space, it’s a process

An illustrative example of this process would be reading a book that continues a story. The memory consolidation of the new information will be better if you associate it with the information you collected in the previous book.

As another example, the more you repeat the lyrics of a song, the better the assimilation of its details and recall.

Third stage: retrieval

The final stage in memory consolidation is none other than their target. This is because, whenever you try to remember something, you usually do so with the intention of retrieving it later. This process consists of going back to your storage and retrieving the information from the long-term memory compartment. There are two ways to do this:

• Recognition. This is perhaps the simplest way. It’s based on the retrieval of information by detecting an associated stimulus among others. For example, you identify features in those stored in your memory when you need to recognize the face of a friend among others.
• Evocation. It’s the automatic search for information. For example, you must evoke the knowledge stored in long-term memory when it’s necessary to remember an address in order to repeat it to a third party at a later time.

The keys to retrieval

Retrieving information is, therefore, a complex process involving several brain structures. In general, the prefrontal cortex (frontal lobe) is in charge of retrieving information stored in the temporal lobe and subcortical areas, such as the hippocampus.

For this reason, the storage capacity is usually damaged when there’s a subcortical lesion. In turn, a cortical lesion damages the ability to access information.

Memory consolidation and age

Most complaints from older people revolve around the inability or difficulty in retrieving memories. Thus, the memories that last longest are those retrieved in greater volume. Therefore, their neural connections strengthen the storage capacity.

Normal or pathological degeneration of the nervous system with age leads to mixing up memories or entirely losing them. Thus, you must take into account the vast volume of content you can store throughout a lifetime. This is because some connections weaken in order to make room for others.

Dreams and memory consolidation

Many authors theorize about the close relationship between sleep and the ability to consolidate memories. In fact, current theories suggest that the weakest connections of the previous day disappear during sleep while the most important ones become stronger.

Likewise, proper rest allows a better activation during wakefulness. Thus, poor rest, drowsiness, attention, and connection problems will also affect the acquisition of memories.

In short, the consolidation of memories is a multifactorial and stepwise process. Moreover, the occurrence of this consolidation depends on other cognitive functions such as attention, planning, inhibition, and every level of memory.