How does memory work? Is it possible to improve your memory? In order to answer these questions, one must look at the different types of memory and how memory is stored in a person's brain.Memory is the mental process of retaining and recalling information or experiences. (1) It is the process of taking events, or facts and storing them in the brain for later use. There are three types of memory: sensory memory, short-term memory, and long-term memory.
Sensory memories are momentary recordings of information in our sensory systems. They are memories evoked through a person's five senses: sight, smell, sound, taste, and touch. Although sensory memory is very brief, different sensory memories last for different amounts of time. Iconic memory is visual sensory memory and it lasts for less than a second. Echoic memory is auditory sensory memory and it lasts for less than 4 seconds. For example, if a person smells a certain smell, the olfactory tract in their nose sends signals to certain parts of the brain called the limbic system. (2) This system helps store the memory of the smell in the brain so that when the person smells the smell again, he or she will remember it.
Short term memory (also called working memory) is the recording of information that is currently being used. However, short term memory only lasts about twenty seconds. George Miller, who calculated the human memory span, found that it can contain at any time 7 chunks (any letter, word, digit, or number) of information. (2) When the brain receives signals of information, the information can be repeated over and over until it is stored, therefore creating a "phonological loop". (4) However, unless a repetition of the information occurs, it will be lost.
Long term memory is the capacity to store information over a long period of time. The capacity for long term memory is unlimited since it can be stored one minute ago or one year ago, and the information can still be retrievable at any time. Some scientists believe that parts of long term memory are permanent while others will eventually weaken over time. (3) Long term memory can be divided into three sections: procedural memory, declarative memory, and remote memory. Procedural memory includes motor skills such as learning how to ride a bike or how to drive a car. "Such memories are slow to acquire but more resistant to change or loss." (4) Declarative memory is used to remember facts, such as names, dates and places. It is easy to learn but also easy to lose. Finally there is episodic memory, which is the record of events that a person stores throughout his or her experience. Recent studies show that these events, as soon as they occur, are sent to a temporary part of the brain called the hippocampus, and that over time they are moved to the neocortex for permanent storage. (5).
When speaking about memory, one needs to look at the parts of the brain that are
involved in memory storage. The hippocampus is a place in...