Source: image "the thinker": public domain; http://commons.wikimedia.org/wiki/File:The_Thinker,_Auguste_Rodin.jpg
Hello, class. So the process of forming memories, most of the sensory information around us, the sights and the sounds that are bombarding us, are not actually remembered, the things that we generally forget only a second or two after we experience them. But if something in our sensory memory catches our attention or if we choose to focus our attention on something in particular, that information is passed on to the next stage of memory, which is the short-term memory.
Now, short-term memory is a system of memory that temporarily stores small amounts of information that we are aware of. So what's important to short-term memory is what we call selective attention. Selective attention allows us to focus on specific details and information and bring them to our conscious awareness. For example, if we're in a noisy classroom, we might not necessarily be able to focus on every student at once. But a teacher can use their selective attention to focus on one particular student that needs help and not be overwhelmed by the sensory information around them.
Now, related to short-term memory is something we call the working memory, which is like our short-term memory in that it allows us to take information and be aware of it consciously for a short period of time. But the working memory not only allows us to be aware of that information, but also to manipulate it and to process it. In other words, this working memory helps us to encode the information with meaning, which we can later use to store it in our long term-memory.
So what do we actually mean by short-term memory or short periods of time and small amounts of information? Well, information can be retained in the short-term memory from anywhere from just a few seconds up to 20 to 30 seconds in length. Now, this period of time can be extended or this information can be kept longer if we repeat or rehearse that information. So if we constantly say it back to ourselves, then essentially what we're doing is we're putting it right back into the short-term memory so we can extend that period of time that we're going to remember it so it's much longer.
However, the short-term memory is very sensitive to interruptions. So, for example, if you're trying to remember a phone number and then somebody comes up and starts talking to you or relating different numbers to you other than the numbers you're trying to remember, you're very likely to suddenly forget those numbers and drop them from your short-term memory. Now, also, your short-term memory can hold approximately seven to nine different pieces of information, which is to say, if you're trying to remember a person's phone number, then remembering seven numbers, that might be something that's very doable. However, when you tack on that area code that might not be familiar to you, all of a sudden, you've got 10 pieces of information, which might be a lot more difficult because it's just outside of our range of short-term memory.
However, we can remember more information if we were to chunk it together. Chunking means putting together the pieces of information into more meaningful groups so we can remember them more. So, for example, if I had four numbers like 1, 9, 8, 4, I might forget those when they're just taken individually. However, if I put them together into 1984 and think of it that way instead, then I'll be able to remember those numbers more easily, and that's a solid chunk of information instead of four individual pieces. I can also attach more meaning to it by saying 1984 is my birthday, which makes it a lot more likely for me to remember that piece of information for longer.
Now, information can be stored within the short-term memory visually, let's say, as images or aspects of images, like we might remember specific colors that go along with whatever we're trying to remember. But more often than not, this information is stored through phonetic meaning, which is to say, the sounds that the information makes. So, for example, when we're trying to remember something in the short term, we often try to remember in terms of let's say like a name of a person or those numbers which we rehearse to ourselves and say back and forth so that we can remember them better. So we're more apt to remember that name in the short term versus trying to remember exactly what that picture or that place might look like.
Now, information in the short-term memory can be further processed and passed on to the long-term memory for longer storage. Or information in the short term can be forgotten. And this is a lot more often occurring. A lot of the stuff in our short-term memory just gets dropped from our memory and forgot because only important things are being remembered in the long term.
So when we think about memory, it's helpful to think of this analogy. We might think of our memory as a sort of office worker who's sitting at a desk and has lots of different papers that are suddenly flying by that desk. Now, most of those papers are ignored. This is the sensory information. They're just tossed directly into the trash. However, certain ones have a big notice at the very top, something red that we want to pay attention to. So that person might-- or that office worker might take those pieces of paper and take a look at them, and that would be our short-term memory.
Now, if those papers are really important, they might take those red-stamped pieces of paper and file them away in the desk for later use. But more often than not, those red-stamped pieces of paper are still sort of your relevant, so they might be looked at for a short period of time and then immediately thrown away again. So that's a good way of thinking about how our memory is going to work as a whole and how all these different parts interact together.