The brain is by far the most sophisticated yet complex organ possessed by man. Its ability to receive, decipher, and store massive amounts of information is to say the least amazing. Over the years scientists and other medical practitioners have dedicated their time and resources into trying to understand how it works, what makes it work and how it relates and function with other organs in the human physiology. As such, they have developed theories that indeed help divide it according to various parts and their functionality.
As a result, in depth research has ensued as pertaining to how the brain processes our thoughts, assist in locomotion and most importantly how it helps us learn and actually retain that knowledge; memory. In this paper, we shall focus on the creation of memory as one of the core functions of the brain. Using documented proof, the discussion shall set to ascertain the fact that the human memory does indeed comprise of multiple cognitive systems as regarding to the different types of memory.
Every field of research must always have a main focus through which questions and answers for that particular study are structured and provided. This having being said, memory research evolves around the belief that there are different types of memory systems that are interconnected and interact with each other to provide a particular outcome (Nyberg and Tulving, 1997).
Additionally, these systems are sub divided into those that handle long- term memories and those that are in charge of short- term memories. The fact that there are separate memory systems seems to be agreed upon by many scholars.
However, theories have been developed that dispute this statement and back the idea that some of these multiple cognitive memory systems function on independent levels depending on the current action or event. In terms of the long term memories, four systems have been irrefutably established over the years whose main aims are to provide insight on how the long term memory works and the situations that institute to its usage.
These systems include the episodic memory system, the semantic, procedural and finally, the Perceptual Representation System (PRS). Over the years, a criterion known as the converging dissociations have been implemented to shed some light on how these different memory systems are totally separate especially in the handling of tasks that use or are affected by any of these systems.
Maine de Biran wrote in 1804 that the brain does indeed consist of multiple memory systems. Among those that he focused on were the mechanical memory which deals with the skeletal coordination, sensitive memory which is in charge of the emotions and other feelings and representative memory which deals with our perception to the facts and events of the external world and influences the decision making structures that govern the same.
In relation to this, Squire acclaims that the different memory systems are developed and function according to the activities and tasks that the brain perceives and our bodies perform. He further describes these memory systems as distinguished by the various tasks that we often carry out (2004). For example reading, walking talking and so forth. To prove this, medical practitioners and memory research experts set an experiment based on the mirror drawing theory to further explain the existence of multiple memory systems.
The experiment was performed to patients who exhibited amnesic tendencies therefore making them perfect candidates. The finding later showed that the eye-hand coordination was not affected by the fact that the patients were amnesic. The patients were able to learn how to draw without any prior recollection of doing this in the past. This example showcased the use of the periodic memory system which focuses on recalling short term memories in relation to repetition of a given task.
The various memory systems are often distinguished through the different ways that they process received information to the brain and the standards through which they operate. As a result of this, new and clearer theories pertaining to memory systems have been established under which the earlier mentioned systems fall under. The theory assumes that memory is defined under two categories which are the declarative memories and the non declarative memories.
Declarative memories are what are referred to in layman’s language as memories. The guiding principle under this type of memory is its ability to identify and simulate the unique attributes that occur at a given place or time. However the term goes deeper than what we remember and term as a memory.
The system focuses on why we remember things or even store information while we discard or forget other memories. This memory generally refers to mans capacity to recollect facts and events on a conscious level. In addition to this, declarative memory allows man to compare and contrast what they remember and it helps in establishing a relationship between these memories and the events that lead to their creation.
On the same note, declarative memory is representational in nature. This means that it is responsible for the way we remember things in our surrounding and consequently how we base their validity through our own experiences. However, this is the memory system that is affected or impaired by amnesia and old age in some cases. It therefore contributes to our performance in various conditions depending on how we perceive the situations.
The semantic and episodic memories consequently fall under the declarative memory system. The semantic memory is described as the memory that is responsible for processing information and facts received about external world.
On the other hand, the episodic memory caters for and supports our ability to perform an action in context to how we did it during its original occurrence. This includes our motor functionalities and coordination. For the episodic memory to be fully effective, it has to depend on other brain systems and the support of the semantic memory, for example the use of the frontal lobe of the brain.
The best example used to show the relationship between these two memory systems would be the case study of K.C. After being in a motorcycle accident, he incurred multiple and severe brain damage and up to date suffers from acute amnesic tendencies. However after a series of tests, it was declared that his brain functionalities were on most cases normal.
He could remember most of the important things in his past and was able to learn new things slowly but surely. However he could not remember his personal involvement in these tests or even in other events that had happened to him. In addition to this, he lacked the ability to project his thoughts into the future or even think about the past no matter the designated duration (Tulving, 2002).
Evidence derived from this case point to the fact that his episodic memory was somewhat impaired after the accident while his semantic memory system was amazingly left intact. That is probably why he could only remember the things and actions that he had over learned or rehearsed in his day to day activities but could not remember things that happened to him less often in his life.
The non-declarative memory system is in total contrast to the declarative systems. In this category, the memories are dispositional and are manifested through the performance of actions rather than recollections of the same. The factors that influence this type of memory systems include perceptual learning, emotional and skeletal responses (classical conditioning) and non associative learning.
As such, the procedural memory system falls under this category. The memories in this category are revealed when the systems within which an event originally occurred are reactivated. This system of memory is unique through its ability to systematically extract common attributes from a series of differentiated occurrences (Squire, 2004). This can best be illustrated by the inclusion of applied knowledge throughout the learning process.
It should be noted that the memory systems used by the brain to some extent operate in parallel to aid behaviors exhibited by human beings. For example, in a case scenario where a child is knocked down by a bicycle this may lead to a permanent declarative memory of the event and at the same time the child may develop a non-declarative memory subjected to the fear of bicycles.
This example shows how the different cognitive memory systems work together in simulating this event. Another illustration that best describes the presence of multiple memory systems would be during child birth whereby the mothers exert fears of what would be and even the process itself.
In addition to this statement, there are situations where one memory system may act as a substitute for another. What we learn, store or retrieve from the brain differs from one person to the other depending on the memory system applied. This is why performance and reception through the learning process differs from one person to another.
In a recent study where the participants were given three-word sentences to memorize and later asked to recall them; the learning occurred rapidly and majority of the participants were able to remember the sentences even in absence of some words. Those that could not recall showed less use of the short term memory which is used to remember things or events within a short period of time.
Consequently, more research has been performed in a bid to improve the usage of both the long and the short term memory for both normal and amnesic patients. On the same note, theories have been created through which the human race can be taught or guided to effectively utilize the various multiple cognitive memory systems while exercising a balanced functionality of the same.
The semantic episodic, periodic and perceptual representation system (PRS) has been put under scrutiny. Three articles have been analyzed so as to further assist in proving that there are multiple cognitive memory systems at work in the human physiology.
As a result, the various systems that have been developed have been discussed at length and illustrations and examples that may provide deeper insight on the memory systems have also been provided. It is clear that the choice as to what we remember or forget depends on the memory system that we implement accompanied by the events or facts that we are involved in.
Further research needs to be conducted in order to give more information about how the memory works. In addition to this, clearer methods need to be established through which those that suffer from various brain and memory disorders get assisted to cope and manage their conditions. Also training techniques should be developed to further assist in the full utilization of all the multiple cognitive memory systems.
Nyberg, L & Tulving, E. (1997). Searching for Memory Systems. Psychology press, pp.121-125
Squire, L, R. (2004). Memory systems of the brain: A brief history and current perspective. Elsevier Inc, pp 171-177.
Tulving, E. (2002). EPISODIC MEMORY: From Mind to Brain. Annual Review of Psychology Volume 53, 2002, pp. 1-25