Memory Is the Process of Maintaining Information over Time

1. Introduction

"Memory is the process of maintaining information over time." (Matlin, 2005)

"Memory is the means by which we draw on our past experiences in order to use this information in the present.' (Sternberg, 1999)

These are the two most exact and used definitions of memory. Memory is the term given to the structures and processes involved in the storage and retrieval of information. Memory plays a very essential role in our lives. Without the memory of the past we can't operate in the present and think about the future. Without memory we would not be able to know what we did yesterday, what we have done today and what will we do tomorrow. Also memory plays a fundamental role in learning processes because if we wouldn't have memory we wouldn't be able to learn new things and this would have been fatal for the continuity of our life. Memory is involved in processing large amounts of information and this takes many different forms, e.g. images, sounds or meaning.

Can you remember what you did last night...what you had for breakfast this morning...what you watched on TV last night? Most of the people know the answer of these questions but how can they? This is the main topic of this discussion; they and we all know these because of the memory. So, we can't imagine our life without memory because, if we were unable to remember, life would be a series of fragmentary, unconnected events. But what exactly is memory and how does it work? These are the main questions that will be answered in this paper of course with the help of cognitive psychologist who deal directly with these topics. In this paper are going to be discussed also the two main types of memory which are short-term memory and long-term memory and the differences between them.

Memory enables us to learn from our past experiences and to use stored information in different situations. Memory is how human beings know themselves in time and construct their identities but, not always the things go in the way they should go. What I mean with this sentence is the fact that people sometimes deal with "memory distortions" which refers to a memory report that differs from what actually occurred.

Another topic of discussion in this paper is the relation of dreams with memory.

"Dreams are a clear indication that the sleeping brain is working on memories at multiple levels, including ways that will directly improve performance."

This is the definition given by the associate professors of psychiatry at Harvard Medical School.

2. Stages of memory

For psychologists the term "memory" covers three important aspects of information processing:

2.1. Encoding and memory

When information comes into our memory system (from sensory input ), it needs to be changed into a form that the system can cope with, so that it can be stored later. For example, a word that is seen in blackboard may be stored if it is changed (encoded) into a sound or meaning (i.e. semantic processing).

There are three main ways that how the information can be encoded:

1. VISUAL (Picture)

2. ACOUSTIC (Sound)

3. SEMANTIC (Meaning)

To explain better these steps I would like to give an example. How do you remember a telephone number if you look it up in the telephone book? If you can see it means that you use visual coding, but if you are repeating it to yourself a lot of times in order to remember it, you are using acoustic coding which means sounds. Evidences show that the first principle in short term memory (STM) is acoustic coding. But, the principle encoding system in long term memory (LTM) appears to be semantic coding (by meaning). However, information in LTM can also be coded both visually and acoustically.

2.2. Storage and memory

This concerns the nature of memory stores, the place where it is stored, how long lasts for (duration), how much can it be stored (capacity) and what kind of information is held. There have been done many researches regarding the differences between STM and LTM and has come to a conclusion that in STM the information can be stored for a very short period of time (0-30 seconds) but, in LTM the information can be stored for a lifetime period.

2.3. Retrieval and memory

This refers to getting information out of storage place for example: if we can't remember something this means that we are unable to retrieve it from storage. When we are asked to bring a memory back the differences between STM and LTM become very clear.

STM is stored and retrieved sequentially. For example, if to a group of participants are given a list of words to remember, and then asked to bring back the 4th word in that list, they will go through the list in the order they heard it in order to retrieve the information.

LTM is stored and retrieved by association. So, we associate different things or events together in order to retrieve the information back.

One important element that can help to retrieve information is organization of information. If we organize information in sequences (alphabetically, by size or by time) we can retrieve it back easily.

To generalize what I explained until now, I would like to give a general example.

In stage 1 when you say to you teacher you name, he or she transformed the sound of your name and encoded the representation into memory. In stage 2 your encoded name was stored in the memory of you teacher until you met in the next class when, in stage 3 your teacher retrieved your name from memory and calls you by your name.

3. Short term memory (STM) & long term memory (LTM)

Characteristics of STM are:

1. Limited information, just 7 items can be stored at the time.

2. Limited duration, storage is very fragile.

3. Encoding (primarily acoustic, even translating visual information into sounds.

4. In STM is used the "chunking" method which means combining small pieces of information.

Characteristics of LTM are:

1. The capacity of LTM could