Human Memory and The Brain

Introduction

The human brain is made of millions of neurons placed in an organized manner to ensure the working of the organ. These neurons communicated with each other using specialized chemicals called neuron transmitters. These chemicals are of several types, and the release varies and depends on several different factors. We know a lot about the brain, and there is a lot that we do not. But, with its complexities and unique coordination system, we have barely scratched the surface.

The human brain is the least understood part of the whole body. This control unit made of organic matter is remarkably complex and is a conundrum of its own. Although the primary function and coordination are pretty defined, the enigma of deeper understanding remains. There are pathways and complex neural connections that are still unknown to humans. The basic communication patterns are known, but how the information is coded in the same chemical is beyond understanding. Behavioral patterns, decisions, preferences, and belief systems originate in the brain, but all processes are unclear. The paradox of memory and emotion is a question of its own.

In this article, we will try to understand human memory and its types, the ways it can be stored in the brain, factors that can trigger memory storage, reasons why a person forgets certain events, and many more. So, keep reading!

Definition of Memory

In scientific terms, memory is defined as the encoding, storage, and retrieval of an experience. In a simpler meaning, it is a recollection of the past. Remembering a number just long enough to dial it and the complete mental image of your wedding day or the trip to Greece decade ago are all memories.

Something as simple as remembering the day’s task involves complex brain work at the back end. The complete archive of it stored in the brain defines who we are—our behaviors, perceptions, and beliefs. Ordinary tasks of daily routine and complex ones like learning a new language are all memory-based. In broader terms, memory is something that has got the human race on the top of the evolutionary chain.

Long term VS Short term Memories

If we try to look into the depth of what memories are there can be two types. Based on the time limit, memories can be broadly classified into long and short-termed memories.

Short Term Memory

A short-term memory has the time span ranging from seconds to a few minutes. They are stored temporarily and then either get to the long-term memory storage, or they are discarded. Let us say someone gives us the mobile number. As the number is new so our memory will retain it for the short term. There are the possible chances that we are going to forget about this number after few moments.

Long Term Memory

These are the memories stored in the brain over a more extended period. They are several short-term memories organized to form a long memory that is stored permanently.  Depending upon the importance and number of recalls, it can fade or be remembered forever. For example, you can recall your 18th birthday but not what you ate on Monday three weeks ago.

Classification of Long-Term Memories

There are several kinds of memories. Depending upon the portion of the brain involved and type of information, they can vary a great deal. Here is a more in-depth look into the classification of long-term memories.

Long term memories can be explicit or implicit. Explicit memory can be further divided into episodic or semantic, and implicit memories can be procedural.

Explicit Memory

These are the memories that require the conscious effort of recalling. As a friend, baby shower three years ago or the knowledge like the earth is a planet.

  • Episodic: These comprise the events of one’s life. For example, the graduation day, a particular Christmas morning, etc. These memories are edited by brain overtime when we recall them in specific contexts. They are not very reliable. Brain’s ability to retain episodic memory depends on the number of sensory stimuli involved and emotions.
  • Semantic: These memories are the general facts and knowledge of things around us. Like cats are mammals, earth has one moon, and a year has twelve months. These memories get updated with new pieces of information. The phenomenon of forgetting is involved in making a place for new facts without cause cognitive dissonance.

Implicit memory

These memories do not involve active or conscious recalling. They are mostly procedural. For example, shift car gear, riding a bike.  

Parts of Brain involved in Memory processes

Technically our brain has many different compartments and they work differently to do certain functions. Not all of the brain is involved in memory. Hippocampus is the main region of the brain involved in memory processes.

Female brain, computer artwork.

When it comes to storing or making a memory Hippocampus is involved. It is the primary regulator of the process of memory retention. It is a seahorse-shaped part of the temporal lobe. It acts as a bridge in engaging all the parts of the brain required to keep a memory. Although it is not involved in retrieving, formation and consolidation are highly dependent on Hippocampus. Consolidation is the fixing or storing a memory permanently.

Suppose due to a dire turn of event someone you know had most of the part of his Hippocampus removed. This person will not be able to remember anything new. Thus, memories will not be retained. However, the ability to recall older memories that happened before removing the Hippocampus will remain unaffected.

Memory Storage in Brain

Generally, we might see a similarity in storage devices or a hard drive and brain, but they are hardly alike. Unlike storage devices, memory in mind is not stored at a specific location. And brain structure is not like a hard drive. It is much more complex, and memories are stored all over it. This is evident from the brain scan. Suppose we are looking at the brain activity of a person recalling a past event. The image will show several neurons firing up located in several different parts of the brain. Let us see how it is stored.

Hippocampus that is involved in making memory comes in and takes the aggregate of several short-termed memories. Suppose the memory for the graduation party can include the food you taste, what you feel like, and what the house smells like. In short, there are several small chunks of memory involved. Hippocampus takes the whole piece and assigns them specific places in the brain center, like the smell, will go to the olfactory region, and sounds go to the auditory area. The neurons on which these are written make connections with each other. This develops a big large memory circuit. The way these connections are made forms the indexing or the flow of how you remember a particular thing.

Role of Memory Retention in Daily tasks

Memory building has a high range of involvement in doing the tasks of daily life. It is mostly dependent on short-termed memory. Ever walked into the room and forget why you came in? Ever forget what were you writing and question you were on during an exam? It has happened when short term memory is not built, and we lose the sense of what we are doing for a while.

Most tasks are process, and we need to actively know and memorize what we are doing every step of the way. How and what you are doing is also important. Thus, things go on in a constant loop. If you do not have short term memory, everything around you will be a giant blur of nothingness. Without short term memory, you will not be able to make long term memories.

Memories shape our Perception and Reality

Everything we are and everything we will ever be is all dependent on memory. Human belief systems, perceptions, and learning are all memory related. Our consciousness is the ultimate reality of us as people with personality and preferences. Memories define actions, and actions are what we become.

Suppose you think racism was not real. But you came across literature contradicting the idea. Your perception said that it was right. So, you committed the new information to your memory. Based on which you acted differently than before. Had it not because of the mind, you might have stuck to your old beliefs.

Memories are triggered by Senses

We now know that the memory comprises of several chunks of information. The more the sense and emotions involved, the easier it will be to access the memory. In the film Ratatouille, when Remy feeds Ratatouille to Anton, the critic gets a flashback of his mother. It shows Anton as a child, eating the same dish that was made by her mother.

This is a clear depiction of how memory works. The taste of a sensory trigger brought the memory of Anton’s mother. Thus, consciousness is based on several such connections. Similarly, a smell of perfume or a song can also take you to a trip down the memory lane because sensory stimuli are involved in accessing a certain memory.

False Memory and Memory implantation

As much as we can trust our brain in keeping the record of everything, it can go through specific alterations. Our memories, especially the episodic ones, are reconstructed and can be falsely stored. One pop culture representation of false memory we have seen is in the movie “Inception.” Tit revolves around going into someone’s subconscious and planting the idea or memory that was not there.

Progress in psychology has proven that memory implantation is indeed possible. With therapy, the memories can be manipulated, and new memories can be implanted. We see the phenomenon of memory implant going on in ‘Westworld’; where AIs are given false human memories to mask their reality and purpose.

Reasons behind Forgetting things

The brain can store a large sum of data in it, but some things are lost. Forgetting is as essential as retaining something. It helps make new memories and move on. Otherwise, we will never progress into the future and cling on everything traumatic we remember. Sometimes we even forget the memories we cherish because this is how the brain works. It lets go of memories so future memories can be made. This is the reason why we even forget our most heartbreaking break up after a while or even our most cherished birthdays.

Here are the three ways it can happen.

Passive Oblivescence

This is the process of losing memory when the neuron connection weakens over time. With aging or when we do not actively recall a memory, the neuron’s link is lost. It can also happen when we lose the stimulus to the mind. The memory might still be there, but we are not able to access it.

Target Forgetting

This happens when our brain actively prunes and discard certain details of a memory. For example, when we learn a new piece of information that contradicts the previous one, the pleasant memory is retained. The conflicted one is dismissed. With target forgetting, we also eliminate our conflicted believes and welcome new perceptions.

Motivated Forgetting

It is a phenomenon of a deliberate forgetting of traumatic and unpleasant events. The exact mechanism is unknown, but when we decide to forget something, the brain steps in. It blocks the neurological pathways to a certain memory, and we forget it.

The Memory Palace

Memory palace or mind place technique is a process of actively archiving important information in an organized manner. It is a compartment technique in which you visualize the space and store memories in certain rooms and areas. Suppose you want to remember a certain sequence. You envision the room and associate them with certain components of the course. So, when you want to remember the sequence you walk through, the place in decided order. In Sherlock, we see Cumberbatch organizing the memory palace and getting rid you unimportant information to keep his memories tidy. This technique is useful in remembering the detail of any event, whether there is an emotional trigger involved or not.

The Horrors of Dementia

Dementia is often commonly regarded as a disease. The truth is dementia is not a disease; it is a group of several symptoms caused by some brain-related disorder. Although speech and language could also be affected, memory loss is relatively common in people with dementia. Stroke and Alzheimer’s disease can lead to dementia. The brain activity, including the normal process of memory-making and accessing, is disrupted. The neurons degenerate, causing the symptoms of memory loss.  Type of damage can vary with the kind of dementia and other condition. 

The memory loss due to aging is different from this. Unlike skin cell that regenerates themselves regularly, nerve cells do not. This means that with the normal process of aging, they will degrade. The amount of neurotransmitter will also decrease. This can lead to the loss of specific memories.

Summary

Memories are the past experiences that are stored in the brain in a highly organized manner. We can recall the memories at any time by just thinking about that time of our life.

Memories are broadly divided into two types;  long term memories and short-term memories. Short term memories last for a few seconds to minutes and are then either discarded or stored permanently. Long term memories are stored for longer periods of time, often for a lifetime.

Long term memories are divided into explicit and implicit ones. A brief detail of this classification has already been discussed.

Hippocampus is the region in the temporal lobe that is involved in memory formation. However, it is not required to recall the memories.

Memories are stored in the form of neuronal connections that are spread throughout the brain. There is no single location in the brain for memory storage. All the areas of the brain are active when a person recalls a past event stored in his memory.

Short term memories help us a lot in performing daily life tasks effectively.

Memories also have a major role in shaping our perception of the world and the realities we believe in.

Special senses such as taste, smell, and vision can trigger memories. They not only are involved in making new memories but are also involved in the recalling and retrieval processes.

Some literature does exist about the possibilities of memory implantation in one’s mind as depicted by some science-fiction movies.

Forgetting different events make space for new memories to be formed in the brain. It can take place in three possible ways as mentioned earlier.

Memory loss is the most common and severe memory disorder seen in old age. Alzheimer’s disease is the most common cause of this disorder.

Memory loss can also occur as a normal aging process.

References

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