As you learned in the previous section, working memory processes information stored temporarily in the short-term store. It is the part of the memory system that reasons, reads, writes, performs computations, converses, and so on. For example, when listening to a speech, an interpreter at the United Nations must:

1. store information in the language being spoken;
2. compare this information to long-term memories of the language into which the speech will be translated;
3. quickly translate it orally for those needing the translation.

While speaking, the translator also must store the next set of words to be translated. This task requires a working memory that is operating at its peak level of performance, and it can be exhausting. Interpreters can perform at this level for only a short time: they need to switch places every few minutes with other interpreters while they rest.

The task of language translation illustrates that working memory and long-term memory constantly interact when processing information held in the short-term store. Most of these interactions — as well as much of the processing that goes on in the phonological loop, the visuo-spatial sketch pad, and the episodic buffer — occur at the preconscious and unconscious levels. Thus, although the short-term store is at the conscious level, not all of working memory is at this level.

Much of the research that has led to our current understanding of the components of working memory and the characteristics of the short-term store has used memory tasks that involve the rapid presentation (through sight or sound) of numbers, words, or letters, followed almost immediately by retrieval. In this research, therefore, the encoding and storing of information makes use of maintenance rehearsal — a type of rehearsal that produces primarily phonemic memory codes.

In everyday life, however, verbal material that we want to remember for a while (such as what you are reading now) typically is not memorized in this way. For instance, when you study for a test, you are unlikely to be given the chance to rapidly read the textbook material and then immediately take the test. Instead, you typically review the material several times over a period of days (or even weeks) before taking the test. And there typically is a relatively long time period — definitely more than 15 seconds — between the last time that you studied for the test and the retrieval of the material during the test. In memory research, this gap is called the retention interval, which is defined as the elapsed time between the encoding (and storing) of information, and the retrieval of this information.

Phonemic encoding of verbal material typically does not produce long-lasting memory codes, which is why students who consistently do well on tests do not rely solely on maintenance rehearsal when studying. Instead, they have learned that thinking deeply about the information and relating it to other things they already know is the best way to receive high test scores. In this case, they are using their working memories to semantically encode the material — to give it meaning. If your goal is to create enduring long-term memories of the material, memories that can be activated in many ways, then it is best to semantically encode the material. Semantic memory codes are produced through elaborative rehearsal — a type of encoding that links new information to information already being maintained in the long-term store. It should be obvious that it is easier to remember something that you are learning if you associate it with something you already know. In the case of the word, retrieval, elaborative rehearsal would include methods of encoding such as the following:

• Forming a visual image of the word "retrieval," perhaps by imagining your hand pulling the word out of your opened head.
• Relating "retrieval" to a past experience, such as thinking of the time that you suddenly remembered the name of your first-grade teacher after being unable to recall it at first.
• Defining "retrieval" in your own words, such as "retrieval means getting information out of a memory store."

There are many ways to elaboratively rehearse new information. Any method that allows you to transform the information into something meaningful would be an example of elaborative rehearsal. For example, I can easily remember the name of anyone named Jeff because that is my name, which is not only already stored in my long-term memory but is also associated with many other long-term memories, thereby making up a very complex network of meanings and emotions. The superior memory for information that has been linked to long-term memories about one's self is called the self-reference effect (Rogers, Kuiper, & Kirker, 1977). The self-reference effect is thought to occur because of the fact that "the self is a well-developed and often-used construct that promotes elaboration and organization of encoded information" (Symons & Johnson, 1997, p. 371). In short, we rapidly encode any information related to ourselves because beliefs and memories about the self are tightly integrated and frequently thought about (but see Klein & Kihlstrom, 1986). That is why, in study questions, I often ask you to think of examples of concepts that are drawn from your own lives: I am trying to take advantage of the self-reference effect to help you learn the material.

Let's use elaborative rehearsal to memorize the six-item word list presented in Section 6-7: ear, axe, zoo, lake, joke, vase. One way to do this would be to create a story out of the words:

A man cut off the ear of a stuffed animal with an axe at the zoo down by the lake. As a joke, he put it in a vase and gave it to his friend.”

As you can see, the story does not have to be a good one, or even one that makes much sense. It only has to be meaningful to you. In this case, the meaning involved organizing the words into an ordered sequence. We also could have elaboratively rehearsed these items by visualizing each one located in a different spot in an imagined scene.

A very common method of elaborative rehearsal is chunking. A chunk is a meaningful unit of information. For example, what at first may seem to be a random sequence of letters or numbers sometimes may be chunked into a smaller number of meaningful items:

n   b   c   c   i   a   t   g   i   f   b   m   w

nbc            cia            tgif            bmw

Four chunks of information can be held in the short-term store easily by almost anyone. By elaborating with chunking, the total amount of information held in the short-term store is dramatically increased. Furthermore, by forming meaningful memory codes, it becomes more likely that the information will be transferred to the long-term store, where it should form enduring memories (see Section 6-9 A to learn more about how to study better by using the findings of memory research).

The process of elaborative rehearsal shows clearly that working memory must be interacting constantly with long-term memory: in order to create semantic memory codes, information in the short-term store must be linked to information in the long-term store. An example reported by Baddeley (1993) illustrates well this interaction between working memory and long-term memory:

John Bransford describes an informal experiment in which experimenter E [let's call him "Ed"] walked into the office of a colleague C [let's call him "Craig"] and said simply, ‘Bill has a red car’. [Ed made this statement with no explanation.] Here is the description of Craig's reactions: ‘Craig looked very surprised, paused for about three seconds, and finally exclaimed “What the hell are you talking about?” After a hasty de-briefing session Craig laughed and told Ed what had gone on in his head. First he thought that Ed was talking about a person named Bill that Craig knew. Then Craig realized that Ed could not in all probability know that person; and besides Bill would never buy a red car. Then Craig thought that Ed may have mixed up the name and really meant to say Jeff (a mutual friend of Craig and Ed). Craig knew that Jeff had ordered a new car, but he was surprised that it was red and that it had arrived so soon. Craig also entertained a few additional hypotheses — all within about three seconds. After that he gave up, thereupon uttering “What the hell are you talking about?”’ (pp. 143-144, modified slightly from the original by using fictitious names)

As you can see from this example and from your own experiences, our working memory constantly takes in information from the outside world and relates it to other information already in long-term memory. This process of elaboratively rehearsing the new information occurs very rapidly. By comparing in working memory the new information with information already in the long-term store, we often are able to make sense of new information, thereby forming semantic codes.

How Much Information Can We Remember?

Because elaborative rehearsal typically takes time and effort, and because we are constantly being bombarded with so much information that it is impossible to elaboratively rehearse more than a small fraction of it, we rapidly forget almost everything that we experience during our lives. Most of the information entering sensory memory is never attended to and, therefore, is never transferred to the short-term store. And then, only a fraction of this information is elaborated well enough to be transferred to the long-term store. Figure 1 presents one way of thinking about the amount of information transferred from one store to the next during a single life episode (the amount of information within the memory stores is indicated by their relative sizes).

Figure 1. The amount of information transferred from one memory store to another during a single life episode

On the other hand, the more that we learn about a particular topic, the less time and effort it takes to elaboratively rehearse new information related to that topic. This is because, when there exists a large amount of related information in the long-term store, there exists more memories to which new information can be linked. In fact, when you become an expert on a topic, elaborative rehearsal for new information related to that topic occurs almost automatically. For example, Schacter (1996) discussed the ability of chess experts to automatically memorize the positions of pieces on a chess board after simply glancing at the board:

After just a single five-second exposure to a board from an actual game, international [chess] masters in one study remembered the locations of nearly all twenty-five pieces, whereas novices could remember the locations of only about four pieces. Moreover, it did not matter whether the masters knew that their memory for the board would be tested later; they performed just as well when they glanced at the board with no intention to remember it. (p. 48, emphasis added)

In order to become a grandmaster in chess, one must encode and store in long-term memory an extraordinary amount of information about past chess games (both those played by the grandmaster and those played by others); and, therefore, grandmasters are able to compare rapidly and effortlessly a current game with their long-term memories of prior games. This feat, however, does not indicate a superior memory ability: grandmasters were no better than anyone else at remembering the positions of randomly placed pieces (Ericsson & Lehmann, 1996; Ross, 2006). In other words, the chess pieces had to be in a meaningful relation to each other on the board in order for grandmasters to demonstrate their ability to rapidly and effortlessly encode and store the positions of the pieces in long-term memory:

To a beginner, a position with 20 chessmen on the board may contain far more than 20 chunks of information, because the pieces can be placed in so many configurations. A grandmaster, however, may see one part of the position as "fianchettoed bishop in the castled kingside," together with a "blockaded king's-Indian-style pawn chain," and thereby cram the entire position into perhaps five or six chunks. (Ross, 2006, p. 69)

The moral of this research for your academic work is clear: the more that you learn about an academic area (such as psychology), the less time and effort will be required to elaboratively rehearse and remember new information in that area.

Study Questions for Section 6-9

1. How does the work of translators show that working memory and long-term memory interact when processing information held in the short-term store?
2. Information in the short-term store is at what level of awareness?
3. At what level of awareness are the mental processes of working memory?
4. How would you define "retention interval" in your own words?
5. How would you define "elaborative rehearsal" in your own words?
6. What kinds of memory codes are produced by elaborative rehearsal?
7. What are some examples of elaborative rehearsal from your everyday life?
8. How are maintenance rehearsal and elaborative rehearsal similar to and different from one another?
9. What are some ways to elaboratively rehearse the concepts you are learning in this course?
10. How would you define the "self-reference effect" in your own words?
11. Why do I ask questions such as the one in #7 above?
12. How would you chunk the following list of 32 numbers in order to remember them more easily: 18411850186518811901192319451963?
13. What information in long-term memory did your working memory use to chunk the numbers in the previous question?
14. With respect to forming new long-term memories, what has research comparing elaborative rehearsal and maintenance rehearsal shown?
15. What is the most effective studying strategy to use in your courses?
16. What happens to the amount of stored information as it is transferred from the sensory store to the short-term store to the long-term store?
17. What reduces the amount of time and effort needed to elaboratively rehearse information in the short-term store?
18. As you develop more and more knowledge about an academic area, what should happen with respect to the amount of time and effort needed to elaboratively rehearse new information in that area? Why?

Go to Quiz 6-9 questions

Go to Readings Section 6-10