The tasks and problems used to study memory have not changed much since the beginnings of memory research in the 1880s (even though the technology used to examine brain structures and the brain activity underlying memory have shown remarkable advances over the last few decades). The memory tasks and memory problems used in memory research fall into three general categories: memorizing information and recalling it later; developing case studies of people with severe amnesia; and identifying factors that cause normal, everyday forgetting.

Memory Tasks

Two types of memory task are often used in memory research. The first involves memorizing lists of items, which then are recalled after various periods of time have elapsed. These lists typically consist of words or numbers. For example, you learned in Section 3-2 that Hermann Ebbinghaus memorized long lists of nonsense syllables (pseudo-words made up of a consonant-vowel-consonant combination, such as nim) over a period of several years. He found that he quickly forgot nonsense syllables.

The second type of memory task involves organizing a series of items into a meaningful whole, such as making up a story from a list of words. A variation of this type of task was developed by Frederic Bartlett during the 1930s. Bartlett gave his subjects a story to read, called The War of the Ghosts. Later, at various intervals, he asked them to retell it. When retelling the story, the subjects usually remembered it with some inaccuracies. In general, when people retell stories, the retelling tends to be shorter than the original story, more unified, and distorted to various degrees by the person’s view regarding the story's theme. Furthermore, stories often arouse emotions, and some studies have shown that a person’s emotional state is important for the content of the memories formed and for what is later remembered. When we respond with a moderate degree of emotion to an event, we tend to remember it better. We also tend to remember details about the event that are consistent with the emotion, even if the details are inaccurate.

Amnesia

People who experience physical or psychological trauma may develop memory disturbances. By linking the type of memory problem to the type of trauma, researchers have learned a great deal about memory functioning. For example, from cases such as Jimmie’s (see previous section), we now know that physical trauma that damages particular areas of the brain may cause permanent amnesia. In a case of amnesia similar to that suffered by Jimmie, a musician named Clive Wearing suffered a viral infection that destroyed parts of his limbic system (especially the hippocampi) and frontal lobes in both hemispheres of his brain. At present, he is unable to remember anything for more than about 20 seconds (anterograde amnesia), which probably is due to the destruction of his hippocampi and other limbic structures. Furthermore, he also cannot remember most life events that occurred after about 10 years of age (retrograde amnesia), which probably involves the destruction of parts of his cerebral cortex, such as his frontal lobes.

In addition to physical trauma, many psychologists argue that psychological trauma (the cognitive and emotional upheaval that follows a highly distressing life event) can cause amnesia for the distressing experience through repression, which is a hypothetical mental process that is said to push distressing mental content from the conscious level of awareness to the unconscious level of awareness. The function of repression is said to be the reduction of anxiety, which occurs when one forgets whatever is making one anxious (by pushing it into the unconscious). For example, students sometimes come to class on the day of a test and seem surprised when the instructor starts to hand out the test. They sometimes state that they had forgotten that the test was to be given that day, even when the instructor had provided many reminders in previous class meetings. Some psychologists and psychiatrists might explain such forgetting as being due to repression of the anxiety-inducing memory of the test date. By studying individuals who have forgotten emotionally traumatic events, we may be able to identify memory processes important for memory retrieval, as well as understand how the desire to forget something may cause us to forget it.

Forgetting in Everyday Life

The study of normal forgetting also has helped memory researchers better understand memory functioning. For example, all of us have experienced having a word on “the tip of the tongue.” When this happens, we feel as if we are just about to recall the word, but become frustrated when the word does not enter consciousness. What is most interesting is that people often are able to remember the first letter of the word and perhaps the number of syllables. Why does this happen? The fact that we often are able to guess correctly several aspects of the word implies that it must be “somewhere” in our memory. Because the word either is very difficult or impossible to recall, we might conclude that the memory is primarily at the unconscious level of awareness, although it is affecting our conscious emotions and thoughts.

Another common example of everyday forgetting is the inability to remember where you have parked your car. You might find yourself walking up and down the aisles of a parking lot, unable to picture where you left it. As soon as you catch sight of the car, however, you probably then remember that you had parked it there. The fact that you remember parking your car in that spot means that, again, the memory was probably at the unconscious level, at least until you saw it, which then brought the memory into consciousness.

As may now be obvious to you, memory research often focuses on forgetting. In fact, it is unlikely that we would be interested in this topic if we did not so often forget what we used to know. For example, why do most of us remember nothing from before the age of about 3 to 4 years — a type of forgetting known as infantile amnesia? Why do most of us have difficulty remembering important incidents from later childhood (such as our eighth birthday party)? Why do we sometimes remember a particular event very differently from a friend or relative who also experienced the event? Alternatively, why do we sometimes suddenly remember an event that we had not thought about in years — an event we apparently had forgotten during the intervening years? The study of memory formation, storage, and retrieval is intimately intertwined with the study of forgetting.

Study Questions for Section 6-3

1. What are the three main methods used by researchers to study memory?
2. What are the two types of memory tasks used in memory research?
3. What are the two types of trauma thought to cause amnesia?
4. What is happening with respect to levels of awareness when a word is on "the tip of your tongue"?
5. What is infantile amnesia?

Go to Quiz 6-3 questions

Go to Readings Section 6-4