The Power and Complexity of Human Memory

I can remember going to a zoo in Canada with my parents when I was 3 years old; I can remember certain things said, that my father bowed out on seeing the lions because his feet hurt, and I can most certainly remember thinking that an angry gorilla was going to escape and throttle me in its gargantuan hands. One thing I cannot remember for the life of me, no matter how hard I try, is what anything looked like during my week there. I have no recollection whatsoever of the surroundings, no matter how much time I spend thinking about it, no matter how many times I present the question to my parents. Why is it that I can remember certain words, certain feelings, but nothing else? Why do people remember certain things, but blank on other things?

Human memory is considered cognitive neuroscience, which is a blend of cognitive psychology and neuroscience, and is composed of three parts: sensory, short-term, and long-term (2). Sensory memory relays messages to the brain from the senses; iconic memory is relayed by sight, echoic memory by sound, and haptic memory by touch. Stimuli received by sensory memory is passed on to short-term memory by attention, meaning that the only things that get saved to sensory memory are the things that we pay attention to. Short-term memory acts as a "scratch pad" for the brain and deals with temporary stimuli. It works in limited frames of time and space, and can be easily interrupted, which is why we become easily distracted and lose our train of thought if we try to do too many things at once. Information that is constantly repeated in short-term memory gets converted to long-term memory, which then stores information for long periods of time and is composed of two types, episodic and semantic. Episodic memory deals with memory of serial experiences and events and is used to construct the way we remember events; semantic memory is full of “facts, concepts, and skills” that we have learned and gathered over periods of time, and is derived from episodic memory (1). Episodic memory is what allows me to remember Canada in a very hazy way; semantic memory is what allows me to remember that the city the zoo was in is Toronto.

Long-term memory has three main functions: storage, deletion, and retrieval. Stored information is taken from short-term memory. Deleted memory is information that is not used for a long period of time and is consequently lost. It is caused by decay and interference, as well as emotional and medical factors; "however, it is debatable whether we actually ever forget anything or whether it becomes increasingly difficult to access certain items from memory.” Memory retrieval occurs in two different ways. Recall reproduces information from memory; recognition notes information that has been seen before. Certain information acts as a trigger to certain memories and retrieval of information. Recognition is less complex, because it works by reacting to cues, and it can aid in recall as well (1). In short, recall is being able to recite the Pledge of Allegiance, and recognition is seeing a mountain laurel and remembering that it is the state flower of Pennsylvania.

It is still unclear as to how the memory functions actually work in the brain; the hippocampus, the amygdala, and the mammillary regions are all attributed in certain memory functions. One theory is that damage to certain brain regions can result in temporary or permanent memory loss; another thought is that loss of memory is more closely related to damage to brain regions that are close to each other or to neurological pathways instead of to specific areas of the brain. There is also another theory, developed by a group of neurologists, that “memories are a field phenomenon and are not stored in the brain at all, but rather accessed through neurological structures”(2).

Many factors affect how much memory is retained, and for how long. Neurological diseases, such as Alzheimer’s disease, can cause varying degrees of memory loss. Amnesia, which is simply the loss of memory, is used to piece together the memory functions of the brain; neurologists look at what is lost and try to figure out what had been there in the first place. An example of very mild temporary memory loss is the “tip-of-the-tongue phenomenon,” which is when we know what we need to say, but cannot express it; for example, I constantly forget names of songs, books, etc., and remember at a later time, when I am not thinking about the thing anymore. The incredible range from amnesia to the “tip-of-the-tongue phenomenon” is proof of the extreme variation of memory loss.

Human memory is so much more than being able to remember the fifty states in alphabetical order; it is, in essence, what makes us individual, what shapes our world from an early age. It becomes ingrained in our personality. We remember what we saw and how it made us feel, and we base our mind sets on that. Memories fade, but they still remain a part of us. I can still see the falling leaves and feel the cool air on my skin and remember every night of trick-or-treat that I partook in, and the smell of baking and the feeling of warmth in an otherwise cold city will always remind me my home in the wintertime. Whether or not memory is more closely tied to psychology or biology is, at this point, irrelevant. The deciding factor, what really matters, is that our memories are an intrinsic part of us, and shape who we are and what we think through enigmatic brain processes that are yet to be fully comprehended.

Works Cited
1.http://www-static.cc.gatech.edu/classes/cs6751_97_winter/Topics/human-cap/memory.html
2. http://en.wikipedia.org/wiki/Human_memory