GETTING INFORMATION FROM LONG-TERM MEMORY

KEY THEME

Retrieval refers to the process of accessing and retrieving stored information in long-term memory.

KEY QUESTIONS

So far, we’ve discussed some of the important factors that affect encoding and storing information in memory. In this section, we will consider factors that influence the retrieval process. Before you read any further, try the demonstration in Figure 6.7. After completing part (a), turn the page and try part (b). We’ll refer to this demonstration throughout this section, so please take a shot at it. After you’ve completed both parts of the demonstration, continue reading.

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Retrieval refers to the process of accessing, or retrieving, stored information. There’s a vast difference between what is stored in our long-term memory and what we can actually access. In many instances, our ability to retrieve stored memory hinges on having an appropriate retrieval cue. A retrieval cue is a clue, prompt, or hint that can help trigger recall of a stored memory. If your performance on the demonstration experiment in Figure 6.7 was like ours, the importance of retrieval cues should have been vividly illustrated.

Let’s compare results. How did you do on the first part of the demonstration, in Figure 6.7(a)? After generating a number of answers, you probably reached a point at which you were unable to remember any more pairs. At that point, you experienced retrieval cue failure, which refers to the inability to recall long-term memories because of inadequate or missing retrieval cues.

You should have done much better on the demonstration in Figure 6.7(b). Why the improvement? In part (b) you were presented with retrieval cues that helped you access your stored memories.

This exercise demonstrates the difference between information that is stored in long-term memory versus the information that you can access. Many of the items on the list that you could not recall in part (a) were not forgotten. They were simply inaccessible—until you had a retrieval cue to help jog your memory. This exercise illustrates that many memories only appear to be forgotten. With the right retrieval cue, you can often access stored information that seemed to be completely unavailable.

COMMON RETRIEVAL GLITCHES

THE TIP-OF-THE-TONGUE EXPERIENCE

Quick—what is the name of the actor who stars in the Ironman film series? How about the four “houses” at Hogwarts in the Harry Potter books? If popular culture isn’t your thing, how about this question: Who wrote the words to “The Star-Spangled Banner”?

Did any of these questions leave you feeling as if you knew the answer but just couldn’t quite recall it? If so, you experienced a common, and frustrating, form of retrieval failure, called the tip-of-the-tongue (TOT)experience. The TOT experience is the inability to get at a bit of information that you’re certain is stored in your memory. Subjectively, it feels as if the information is very close, but just out of reach—or on the tip of your tongue (Schwartz, 2002, 2011).

TOT experiences appear to be universal, and the “tongue” metaphor is used to describe the experience in many cultures (Brennen & others, 2007; Schwartz, 1999, 2002). On average, people have about one TOT experience per week, and TOT experiences with particular words tend to recur (D’Angelo & Humphreys, 2015). Although people of all ages experience such word-finding memory glitches, TOT experiences tend to be more common among older adults than younger adults (Farrell & Abrams, 2011).

When experiencing this sort of retrieval failure, people can almost always dredge up partial responses or related bits of information from their memory. About half the time, people can accurately identify the first letter of the target word and the number of syllables in it. They can also often produce words with similar meanings or sounds. While momentarily frustrating, about 90 percent of TOT experiences are eventually resolved, often within a few minutes.

Tip-of-the-tongue experiences illustrate that retrieving information is not an all-or-nothing process. Often, we remember bits and pieces of what we want to remember. In many instances, information is stored in memory but is not accessible without the right retrieval cues. TOT experiences also emphasize that information stored in memory is organized and connected in relatively logical ways. As you mentally struggle to retrieve the blocked information, logically connected bits of information are frequently triggered. In many instances, these related tidbits of information act as additional retrieval cues, helping you access the desired memory.

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TESTING RETRIEVAL

RECALL, CUED RECALL, AND RECOGNITION

The first part of the demonstration in Figure 6.7 illustrated the use of recall as a strategy to measure memory. Recall, also called free recall, involves producing information using no retrieval cues. This is the memory measure that’s used on essay tests. Other than the essay questions themselves, an essay test provides no additional retrieval cues to help jog your memory.

The second part of the demonstration used a different memory measurement, called cued recall. Cued recall involves remembering an item of information in response to a retrieval cue. Fill-in-the-blank and matching questions are examples of cued-recall tests.

A third memory measurement is recognition, which involves identifying the correct information from several possible choices. Multiple-choice tests involve recognition as a measure of long-term memory. The multiple-choice question provides you with one correct answer and several wrong answers. If you have stored the information in your long-term memory, you should be able to recognize the correct answer.

Cued-recall and recognition tests are clearly to the student’s advantage. Because these kinds of tests provide retrieval cues, the likelihood that you will be able to access stored information is increased.

THE SERIAL POSITION EFFECT

Notice that the first part of the demonstration in Figure 6.7 did not ask you to recall the sentences in any particular order. Instead, the demonstration tested free recall—you could recall the items in any order. Take another look at your answers to Figure 6.7(a). Do you notice any sort of pattern to the items that you did recall?

Most people are least likely to recall items from the middle of the list. This pattern of responses is called the serial position effect, which refers to the tendency to retrieve information more easily from the beginning and the end of a list rather than from the middle. There are two parts to the serial position effect. The tendency to recall the first items in a list is called the primacy effect, and the tendency to recall the final items in a list is called the recency effect.

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The primacy effect is especially prominent when you have to engage in serial recall, that is, when you need to remember a list of items in their original order. Remembering speeches, telephone numbers, and directions are a few examples of serial recall.

KEY THEME

According to the encoding specificity principle, re-creating the original learning conditions makes retrieval easier.

KEY QUESTIONS

One of the best ways to increase access to information in memory is to re-create the original learning conditions. This simple idea is formally called the encoding specificity principle (Tulving, 1983). As a general rule, the more closely retrieval cues match the original learning conditions, the more likely it is that retrieval will occur.

For example, have you ever had trouble remembering some bit of information during a test but immediately recalled it as you entered the library where you normally study? When you intentionally try to remember some bit of information, such as the definition of a term, you often encode much more into memory than just that isolated bit of information. As you study in the library, at some level you’re aware of all kinds of environmental cues. These cues might include the sights, sounds, and aromas within that particular situation. The environmental cues in a particular context can become encoded as part of the unique memories you form while in that context. These same environmental cues can act as retrieval cues to help you access the memories formed in that context.

This particular form of encoding specificity is called the context effect. The context effect is the tendency to remember information more easily when the retrieval occurs in the same setting in which you originally learned the information. Thus, the environmental cues in the library where you normally study act as additional retrieval cues that help jog your memory. Of course, it’s too late to help your test score, but the memory was there.

A different form of encoding specificity is called mood congruence—the idea that a given mood tends to evoke memories that are consistent with that mood. In other words, a specific emotional state can act as a retrieval cue that evokes memories of events involving the same emotion. So, when you’re in a positive mood, you’re more likely to recall positive memories. When you’re feeling blue, you’re more likely to recall negative or unpleasant memories.

VIVID EVENTS, ACCURATE MEMORIES?

If you rummage around your own memories, you’ll quickly discover that highly unusual, surprising, or even bizarre experiences are easier to retrieve from memory than are routine events (Geraci & Manzano, 2010). Such memories are said to be characterized by a high degree of distinctiveness. That is, the encoded information represents a unique, different, or unusual memory.

Various events can create vivid, distinctive, and long-lasting memories that are sometimes referred to as flashbulb memories (Brown & Kulik, 1982). Just as a camera flash captures the specific details of a scene, a flashbulb memory is thought to involve the recall of very specific details or images surrounding a significant, rare, or vivid event.

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Do flashbulb memories literally capture specific details, like the details of a photograph, that are unaffected by the passage of time? Emotionally charged national events have provided a unique opportunity to study flashbulb memories. On September 12, 2001, a day after the World Trade Center attacks, psychologists Jennifer Talarico and David Rubin (2003, 2007) asked university students to complete questionnaires about how they learned about the terrorist attacks. For comparison, students also described an ordinary, everyday event that had recently occurred.

Over the next year, students were periodically asked to again describe their memories of the 9/11 attacks and of the ordinary event. When the researchers compared these accounts to the original, September 12 reports, they discovered that both the flashbulb and everyday memories had decayed over time, with an increasing number of inconsistent details. But when asked to rate the vividness and accuracy of both memories, only the ratings for the ordinary memory declined. Despite being just as inconsistent as the ordinary memories, the students perceived their flashbulb memories of 9/11 as being more accurate.

A similar pattern was observed in a 10-year, longitudinal study involving three thousand participants in seven different U.S. cities who described how they learned of the 9/11 attacks (Hirst & others, 2015). Within the first year after the attack, participants rapidly forgot details. Despite inconsistencies between original reports and memories of the event, participants’ confidence in the accuracy of their memories remained high. Interestingly, proximity to the attacks was not associated with more accurate memories, but was associated with confidence levels. People who lived in New York at the time of the attacks had much higher levels of confidence in their memories, but their memories were no more accurate than those of non-New Yorkers.

Although flashbulb memories can seem incredibly vivid, they appear to function just as normal, everyday memories do (Talarico & Rubin, 2009; Hirst & others, 2015). We remember some details, forget some details, and think we remember some details. What does seem to distinguish flashbulb memories from ordinary memories is the high degree of confidence the person has in the accuracy of these memories. But clearly, confidence in a memory is no guarantee of accuracy. We’ll come back to that important point shortly.