Chapter 7: Encoding, Retrieval, and Consolidation PDF

SOME QUESTIONS WE WILL CONSIDER ◗ What is the best way to store information in long-term memory? (193) ◗ How can the results of memory research be used to create more effective study techniques? (199) ◗ What are some techniques we can use to help us get information out of long-term memory when we ne...

SOME QUESTIONS WE WILL CONSIDER ◗ What is the best way to store information in long-term memory? (193) ◗ How can the results of memory research be used to create more effective study techniques? (199) ◗ What are some techniques we can use to help us get information out of long-term memory when we need it? (202) ◗ How is it possible that a lifetime of experiences and accumulated knowledge can be stored in neurons? (208) Y ou may have heard the phrase “living in the moment.” It is perhaps good advice when applied to dealing with life, because what it means is to be conscious of the present moment without dwelling on the past or being concerned or anxious about the future. But while this prescription may work as a way to get more out of daily life, the reality is that living just in the moment isn’t really living at all, as illustrated by cases such as that of HM (p. 170), who couldn’t remember anything that happened more than 30 to 60 seconds in his past. He was literally living only in the moment, and so was unable to function independently. While HM may be an extreme example, the fact is that even when you are “living in the moment,” that moment is influenced by what’s happened to you in the past and perhaps even your expectation of what is going to happen in the future. Our knowledge of the past, it turns out, is essential for our survival. We use knowledge about the immediate past (what just happened), and knowledge accumulated through years of experiences to deal with the environment (finding our way, keeping appointments, avoiding dangerous situations); relationships (knowing things about other people); work and school (facts and procedures necessary for succeeding in occupations or taking exams); and anticipating and planning for the future (see page 172). In this chapter, we continue our consideration of long-term memory (LTM) by focusing on how to get information into LTM and how to get it out. We will focus on two processes: encoding (the process of acquiring information and transferring it to LTM) and retrieval (bringing information into consciousness by transferring it from LTM to working memory). 192 We introduced encoding in Chapter 5, when we described how Rachel stored a phone number in her LTM as she was ordering pizza. Notice that the term encoding is similar to the term coding that we discussed in relation to STM and LTM in Chapter 6. Some authors use these terms interchangeably. We have used the term coding to refer to the form in which information is represented. For example, a word can be coded visually or by its sound or by its meaning. We will use the term encoding to refer to the process used to get information into LTM. For example, a word can be encoded by repeating it over and over, by thinking of other words that rhyme with it, or by using it in a sentence. One of the main messages in this chapter is that some methods of encoding are more effective than others. You can appreciate the importance of retrieval by imagining you just finished studying for an exam and are pretty sure you have encoded the material that is likely to be on the exam into your LTM. But the moment of truth occurs when you are in the exam and you have to remember some of this information to answer a question. No matter how much information you’ve encoded, it won’t help you do well on the exam unless you can retrieve it, and interestingly enough, one of the main factors that determines whether you can retrieve information from LTM is the way that information was encoded when you learned it. In the next section, we will focus on how information is encoded into LTM. We will then consider retrieval and how it relates to encoding. Copyright 2019 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. WCN 02-200-202 08271_ch07_ptg01.indd 192 4/18/18 4:36 PM Encoding : Getting Information into Long-Term Memory 193 Encoding: Getting Information into Long-Term Memory There are a number of ways of getting information into long-term memory, some of which are more effective than others. One example is provided by different ways of rehearsing information. Consider, for example, holding a phone number in your memory by repeating it over and over. If you do this without any consideration of meaning or making connections with other information, you are engaging in maintenance rehearsal. Typically, this type of rehearsal results in little or no encoding and therefore poor memory, so you don’t remember the number when you want to call it again later. But what if, instead of mindlessly repeating the phone number, you find a way to relate it to something meaningful. As it turns out, the first three numbers are the same as your phone number, and the last four just happen to be the year you were born! Coincidence as this may be, it provides an example of being able to remember the number by considering meaning or making connections to other information. When you do that, you are engaging in elaborative rehearsal, which results in better memory than maintenance rehearsal. This contrast between maintenance rehearsal and elaborative rehearsal is one example of how encoding can influence the ability to retrieve memories. We will now consider a number of other examples, many of which show that better memory is associated with encoding that is based on meaning and making connections. Levels of Processing Theory 1. A question about the physical features of the word. For example, participants see the word bird and are asked whether it is printed in capital letters (Figure 7.1a). 2. A question about rhyming. For example, participants see the word train and are asked if it rhymes with the word pain. 3. A fill-in-the-blanks question. For example, participants see the word car and are asked if it fits into the sentence “He saw a _______ on the street.” Percent correct An early idea linking the type of encoding to retrieval, proposed by Fergus Craik and Robert Lockhart (1972), is called levels of processing theory. According to levels of processing theory, memory depends on the depth of processing that an item receives. Depth of processing distinguishes between shallow processing and deep processing. Shallow processing involves little attention to meaning, as when a phone number is repeated over and over or attention is focused on a word’s physical features such as whether it is printed in lowercase or capital letters. Deep processing involves close attention and elaborative rehearsal that focuses on an item’s meaning and its relationship to something else. According to levels of processing theory, deep processing results in better memory than Ask question. Present Example: word. shallow processing (Craik, 2002). Capital letters? Example: bird In an experiment testing memory following different levels of processing, Craik and Endel Tulving (a) (1975) presented words to participants and asked them three different types of questions: Answer question. Example: No 100 50 0 Capital letters? Rhyme? Fill in the blanks (b) ➤ Figure 7.1 (a) Sequence of events in Craik and Tulving’s (1975) experiment. (b) Results of this experiment. Deeper processing (fill-in-the-blanks question) is associated with better memory. Copyright 2019 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. WCN 02-200-202 08271_ch07_ptg01.indd 193 4/18/18 4:36 PM 194 CHAPTER 7 LTM: Encoding, Retrieval , and Consolidation The three types of questions were designed to create different levels of processing: (1) physical features 5 shallow processing; (2) rhyming 5 deeper processing; (3) fill in the blanks 5 deepest processing. After participants responded to these three types of questions, they were given a memory test to see how well they recalled the words. The results, shown in Figure 7.1b, indicate that deeper processing is associated with better memory. The basic idea behind levels of processing theory—that memory retrieval is affected by how items are encoded—has led to a great deal of research that has demonstrated this relationship. For example, research at about the same time that levels of processing theory was proposed showed that forming images can improve memory for word pairs. Percent correct recall 15 10 Boat-tree Boat-tree Boat-tree Forming Visual Images 5 0 Repetition group Imagery group ➤ Figure 7.2 Results of the Bower and Winzenz (1970) experiment. Participants in the repetition group repeated word pairs. Participants in the imagery group formed images representing the pairs. Gordon Bower and David Winzenz (1970) decided to test whether using visual imagery—generating images in your head to connect words visually—can enhance memory. They used a procedure called paired-associate learning, in which a list of word pairs is presented. Later, the first word of each pair is presented, and the participant’s task is to remember the word it was paired with. Bower and Winzenz presented a list of 15 pairs of nouns, such as boat–tree, to participants for 5 seconds each. One group was told to silently repeat the pairs as they were presented, and another group was told to form a mental picture in which the two items were interacting. When participants were later given the first word and asked to recall the second one for each pair, the participants who had created images remembered more than twice as many words as the participants who had just repeated the word pairs (Figure 7.2). Percent remembered Linking Words to Yourself 60 40 20 Self condition Common condition ➤ Figure 7.3 Results of Leshikar et al.’s (2015) self-reference experiment. Recognition was better for words that the participants had associated with themselves. Another example of how memory is improved by encoding is the self-reference effect: Memory is better if you are asked to relate a word to yourself. Eric Leshikar and coworkers (2015) demonstrated the self-reference effect by having participants in the study phase of their experiment look at a series of adjectives presented on a screen for about 3 seconds each. Examples of adjectives are loyal, happy, cultural, talkative, lazy, and conformist. There were two conditions, the self condition, in which participants indicated whether the adjective described themselves (yes or no), and the common condition, in which participants indicated whether the word was commonly used (yes or no). In a recognition test that immediately followed the study phase, participants were presented with words from the study phase plus words that weren’t presented and were told to indicate whether they remembered the words from before. The results, shown in Figure 7.3, show that memory was better for the self condition than the common condition. Why are participants more likely to remember words they connect to themselves? One possible explanation is that the words become linked to something the participants know well—themselves. Generally, statements that result in richer, more detailed representations in a person’s mind result in better memory (also see Rogers et al., 1977; Sui & Humphreys, 2015). Generating Information Generating material yourself, rather than passively receiving it, enhances learning and retention. Norman Slameka and Peter Graf (1978) demonstrated this effect, called the generation effect, by having participants study a list of word pairs in two different ways: Copyright 2019 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. WCN 02-200-202 08271_ch07_ptg01.indd 194 4/18/18 4:36 PM Encoding : Getting Information into Long-Term Memory 195 1. Read group: Read these pairs of related words. king–crown; horse–saddle; lamp– shade; etc. 2. Generate group: Fill in the blank with a word that is related to the first word. king– cr _______; horse–sa _______; lamp–sh _______; etc. After either reading the pairs of words (read group) or generating the list of word pairs based on the word and first two letters of the second word (generate group), participants were presented with the first word in each pair and were told to indicate the word that went with it. Participants who had generated the second word in each pair were able to reproduce 28 percent more word pairs than participants who had just read the word pairs. You might guess that this finding has some important implications for studying for exams. We will return to this idea in the next section. Organizing Information Folders on your computer’s desktop, computerized library catalogs, and tabs that separate different subjects in your notebook are all designed to organize information so it can be accessed more efficiently. The memory system also uses organization to access information. This has been shown in a number of ways. D E M O N S T R AT I O N Remembering a List Get paper and pen ready. Read the following words, then cover them and write down as many as you can. apple, desk, shoe, sofa, plum, chair, cherry, coat, lamp, pants, grape, hat, melon, table, gloves STOP! Cover the words and write down the ones you remember, before reading further. Look at the list you created and notice whether similar items (for example, apple, plum, cherry; shoe, coat, pants) are grouped together. If they are, your result is similar to the result of research that shows that participants spontaneously organize items as they recall them ( Jenkins & Russell, 1952). One reason for this result is that remembering words in a particular category may serve as a retrieval cue—a word or other stimulus that helps a person remember information stored in memory. In this case, a word in a particular category, such as fruits, serves as a retrieval cue for other words in that category. So, remembering the word apple is a retrieval cue for other fruits, such as grape or plum, and therefore creates a recall list that is more organized than the original list that you read. If words presented randomly become organized in the mind, what happens when words are presented in an organized way during encoding? Gordon Bower and coworkers (1969) answered this question by presenting material to be learned in an “organizational tree,” which organized a number of words according to categories. For example, one tree organized the names of different minerals by grouping together precious stones, rare metals, and so on (Figure 7.4). One group of participants studied four separate trees for minerals, animals, clothing, and transportation for 1 minute each and were then asked to recall as many words as they could from all four trees. In the recall test, participants tended to organize their responses in the same way the trees were organized, first saying “minerals,” then “metals,” then “common,” and so on. Participants in this group recalled an average of 73 words from all four trees. Another group of participants also saw four trees, but the words were randomized, so that each tree contained a random assortment of minerals, animals, clothing, and Copyright 2019 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. WCN 02-200-202 08271_ch07_ptg01.indd 195 4/18/18 4:36 PM 196 CHAPTER 7 LTM: Encoding, Retrieval , and Consolidation Minerals Metals Stones Rare Common Alloys Precious Masonry Platinum Silver Gold Aluminum Copper Lead Iron Bronze Steel Brass Sapphire Emerald Diamond Ruby Limestone Granite Marble Slate ➤ Figure 7.4 The organized “tree” for minerals used in Bower et al.’s (1969) experiment on the effect of organization on memory. (Source: G. H. Bower et al., Hierarchical retrieval schemes in recall of categorized word lists, Journal of Verbal Learning and Verbal Behavior, 8, 323–343, Figure 1. Copyright © 1969 Elsevier Ltd. Republished with permission.) transportation. These participants were able to remember only 21 words from all four trees. Thus, organizing material to be remembered results in substantially better recall. Perhaps this is something to keep in mind when creating study materials for an exam. You might, for example, find it useful to organize material you are studying for your cognitive psychology exam in trees like the one in Figure 7.5. If presenting material in an organized way improves memory, we might expect that preventing organization from happening would reduce the ability to remember. This effect was illustrated by John Bransford and Marcia Johnson (1972), who asked their participants to read the following passage: If the balloons popped, the sound wouldn’t be able to carry since everything would be too far away from the correct floor. A closed window would also prevent the sound from carrying, since most buildings tend to be well insulated. Since the whole operation depends on the steady flow of electricity, a break in the middle of the wire would also cause problems. Of course, the fellow could shout, but the human voice is FACTORS THAT AID ENCODING Create connections Imagery (tree–boat) Link to self (self-reference effect) Active creation Generate information Testing Organization Recall by groups (spontaneous grouping of fruits, etc.) Present in an organized way (“tree” experiment) Meaningful framework (balloon experiment) ➤ Figure 7.5 An organized tree for some of the material about encoding presented in this section of the chapter. Copyright 2019 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. WCN 02-200-202 08271_ch07_ptg01.indd 196 4/18/18 4:36 PM Encoding : Getting Information into Long-Term Memory 197 not loud enough to carry that far. An additional problem is that the string could break on the instrument. Then there would be no accompaniment to the message. It is clear that the best situation would involve less distance. Then there would be fewer potential problems. With face to face contact, the least number of things could go wrong. (p. 719) What was that all about? Although each sentence makes sense, it was probably difficult to picture what was happening, based on the passage. Bransford and Johnson’s participants not only found it difficult to picture what was going on, but they also found it extremely difficult to remember this passage. To make sense of this passage, look at Figure 7.6 on page 198 and then reread the passage. When you do this, the passage makes more sense. Bransford and Johnson’s (1972) participants who saw this picture before they read the passage remembered twice as much from the passage as participants who did not see the picture or participants who saw the picture after they read the passage. The key here is organization. The picture provides a mental framework that helps the reader link one sentence to the next to create a meaningful story. The resulting organization makes this passage easier to comprehend and much easier to remember later. This example illustrates once again that the ability to remember material depends on how that material is programmed into the mind. Relating Words to Survival Value James Nairne (2010) proposes that we can understand how memory works by considering its function, because, through the process of evolution, memory was shaped to increase the ability to survive, especially in situations experienced by our ancestors, who were faced with basic survival challenges such as finding food and evading predators. In an experiment designed to test this idea, Nairne had participants imagine that they were stranded on the grassland of a foreign country without any basic survival materials. As they were imagining this, they were presented with a list of words. Their task was to rate each word based on how relevant it would be for finding supplies of food and water and providing protection from predators. Later, participants were given a surprise memory test that showed that carrying out this “survival” task while reading the words resulted in better memory than other elaborative encoding procedures we have described, such as forming visual images, linking words to yourself, or generating information. Based on this result, Nairne concluded that “survival processing” is a powerful tool for encoding items into memory. Other researchers, have, however, shown that memory is also enhanced by relating words to situations that our ancestors didn’t experience, such as being attacked by zombies, either in the grasslands or in a modern city (Soderstrom & McCabe, 2011), or planning for an upcoming camping trip (Klein et al., 2010, 2011). Because of results such as these, some researchers question the idea that our memory systems are tuned to respond to survival situation faced by our ancient ancestors. There is no question, however, that situations that involve survival can enhance memory. Retrieval Practice All of the previous examples have shown that the way material is studied can affect memory for the material, with elaborative processing resulting in better memory. But the elaboration that results in better memory can also be achieved by testing memory, or, to put it another way, to practice memory retrieval. The retrieval practice effect was demonstrated in an experiment by Jeffrey Karpicke and Henry Roediger (2008). In their experiment, participants studied a list Copyright 2019 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. WCN 02-200-202 08271_ch07_ptg01.indd 197 4/18/18 4:36 PM 198 CHAPTER 7 LTM: Encoding, Retrieval , and Consolidation of 40 Swahili–English word pairs, such as mashua–boat, and then saw one of the words in each pair and were asked to remember the other word. The design of the experiment is shown in Table 7.1. There were three groups. In the “first study and test” phase of the experiment (Column 1) all three groups studied all of the pairs and then were tested on all of the pairs. When tested, they recalled some pairs and didn’t recall others. In the “repeat study and test” phase of the experiment (Column 2) the three groups had different study and test experiences. Group 1 continued the original procedure. In each study-test session they studied all pairs and were tested on all pairs until their performance reached 100 percent. For Group 2 the study part of the study-test sequence was changed. Once a pair was recalled correctly in a test, it was no longer studied in next study sessions. However, all of the pairs were tested during each test session until performance reached 100 percent. This group therefore studied less of the pairs as the experiment progressed. For Group 3 the test part of the study-test sequence was changed. Once a pair was recalled correctly, it was no longer tested during the next test sessions. This group was therefore tested on less of the pairs as the experiment progressed. When tested a week later, Groups 1 and 2 recalled 81 percent of the pairs, but Group 3 only recalled 36 percent of the pairs. This result shows that being tested is important for learning because when testing was stopped for Group 3 once items were recalled correctly, performance decreased. In contrast, the results for Group 2 show that cessation of studying did not affect performance. The enhanced performance due to retrieval practice is called the testing effect. It ➤ Figure 7.6 Picture used by Bransford and has been demonstrated in a large number of experiments, both in the laboratory Johnson (1972) to illustrate the effect of organization on memory. and in classroom settings (Karpicke et al., 2009). For example, testing resulted in better performance than rereading for eighth-grade students’ performance on a history test (Carpenter et al., 2009) and for college students’ performance on an exam in a brain and behavior course (McDaniel et al., 2007). All of the above examples of different conditions that aid encoding provide an important message for students studying for exams: When studying, use techniques that result in elaborative processing, and keep testing yourself, even after the material is “learned,” because testing provides a way of elaborating the material. TABLE 7.1 Design and Results of Karpicke and Roediger (2008) Experiment First Study and Test Session STUDY TEST Repeat Study and Test Sessions STUDY TEST Test After One Week % Correct Group 1 All pairs All pairs All pairs All pairs 81 Group 2 (less studying) All pairs All pairs Only pairs NOT recalled in previous tests All pairs 81 Group 3 (less testing) All pairs All pairs All pairs Only pairs NOT recalled in previous tests 36 Copyright 2019 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. WCN 02-200-202 08271_ch07_ptg01.indd 198 4/18/18 4:36 PM Effective Studying 199 T E ST YOUR SELF 7.1 1. What is encoding? Retrieval? Why is each necessary for successful memory? 2. What is the difference between elaborative rehearsal and maintenance rehearsal in terms of (a) the procedures associated with each type of rehearsal and (b) their effectiveness for creating long-term memories? 3. What is levels of processing theory? Be sure you understand depth of processing, shallow processing, and deep processing. What would levels of processing theory say about the difference between maintenance rehearsal and elaborative rehearsal? 4. Give examples of how memory for a word can be increased by (a) forming visual images, (b) linking words to yourself, (c) generating the word during acquisition, (d) organizing information, (e) rating the word in terms of survival, and (f) practicing retrieval. What do these procedures have in common? 5. What is the testing effect? 6. What do the results of the procedures in question 5 indicate about the relationship between encoding and retrieval? Effective Studying How do you study? Students have developed numerous techniques, which vary depending on the type of material to be studied and what works for a particular student. When students are asked to describe their study techniques, the most popular are highlighting material in text or notes (Bell & Limber, 2010; Gurung et al., 2010) and rereading text or notes (Carrier, 2003; Karpicke et al., 2009; Wissman et al., 2012). Unfortunately, research has generally found that these popular techniques are not very effective (Dunlosky et al., 2013). Apparently, students use highlighting and rereading because they are easy to use, and because they are not aware of more effective methods. We will describe a number of ways of learning material that have been shown to be effective. Even if you think highlighting and rereading work for you, you might want to consider also using one or more of the following techniques the next time you study. Elaborate A process that helps transfer the material you are reading into long-term memory is elaboration—thinking about what you are reading and giving it meaning by relating it to other things that you know. This becomes easier as you learn more because what you have learned creates a structure on which to hang new information. Techniques based on association, such as creating images that link two things, as in Figure 7.2, often prove useful for learning individual words or definitions. For example, there is a memory effect called proactive interference, which occurs when previously learned information interferes with learning new information. The effect of proactive interference is illustrated by what might happen when learning French vocabulary words makes it more difficult to learn a list of Spanish words a little later. How can you remember the term proactive interference? My solution was to think of a “pro” football player smashing everything in his path as he runs forward in time, to remind me that proactive interference is the past influencing the present. I no longer need this image to remember what proactive interference is, but it was helpful when I was first learning this concept. Copyright 2019 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. WCN 02-200-202 08271_ch07_ptg01.indd 199 4/18/18 4:36 PM 200 CHAPTER 7 LTM: Encoding, Retrieval , and Consolidation Generate and Test The results of research on the generation effect (page 194) indicate that devising situations in which you take an active role in creating material is a powerful way to achieve strong encoding and good long-term retrieval. And research on retrieval practice and the testing effect (page 197) indicates that repeatedly testing yourself on material you are studying pays dividends in improved memory. Testing is actually a form of generation, because it requires active involvement with the material. If you were going to test yourself, how would you get the test questions? One way would be to use the questions that are sometimes provided in the book or study guide, such as the Test Yourself questions in this book. Another way is to make up questions yourself. Because making up the questions involves active engagement with the material, it strengthens encoding of the material. Research has shown that students who read a text with the idea of making up questions did as well on an exam as students who read a text with the idea of answering questions later, and both groups did better than a group of students who did not create or answer questions (Frase, 1975). Research has shown that many students believe that reviewing the material is more effective than testing themselves on it, but when they do test themselves, it is usually to determine how they are doing, not as a tool to increase learning (Kornell & Son, 2009). As it turns out, self-testing accomplishes two things: It indicates what you know and increases your ability to remember what you know later. Organize The goal of organizing material is to create a framework that helps relate some information to other information to make the material more meaningful and therefore strengthen encoding. Organization can be achieved by making “trees,” as in Figure 7.5, or outlines or lists that group similar facts or principles together. Organization also helps reduce the load on your memory. We can illustrate this by looking at a perceptual example. If you see the black and white pattern in Figure 3.17 (page 72) as unrelated black and white areas, it is extremely difficult to describe what it is. However, once you’ve seen this pattern as a Dalmatian, it becomes meaningful and therefore much easier to describe and to remember (Wiseman & Neisser, 1974). Organization relates to the phenomenon of chunking that we discussed in Chapter 5. Grouping small elements into larger, more meaningful ones increases memory. Organizing material is one way to achieve this. Take Breaks Saying “Take breaks” is another way of saying “Study in a number of shorter study sessions rather than trying to learn everything at once,” or “Don’t cram.” There are good reasons to say these things. Research has shown that memory is better when studying is broken into a number of short sessions, with breaks in between, than when it is concentrated in one long session, even if the total study time is the same. This advantage for short study sessions is called the spacing effect (Reder & Anderson, 1982; Smith & Rothkopf, 1984). Another angle on taking breaks is provided by research that shows that memory performance is enhanced if sleep follows learning (page 214). Although sleeping to avoid studying is probably not a good idea, sleeping soon after studying can improve a process called consolidation (which we will discuss later in this chapter) and which results in stronger memories. Avoid “Illusions of Learning” One of the conclusions of both basic memory research and research on specific study techniques is that some study techniques favored by students may appear to be more effective Copyright 2019 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. WCN 02-200-202 08271_ch07_ptg01.indd 200 4/18/18 4:36 PM Effective Studying 201 than they actually are. For example, one reason for the popularity of rereading as a study technique is that it can create the illusion that learning is occurring. This happens because reading and rereading material results in greater fluency—that is, repetition causes the reading to become easier and easier. But although this enhanced ease of reading creates the illusion that the material is being learned, increased fluency doesn’t necessarily translate into better memory for the material. Another mechanism that creates the illusion of learning is the familiarity effect. Rereading causes material to become familiar, so when you encounter it a second or third time, there is a tendency to interpret this familiarity as indicating that you know the material. Unfortunately, recognizing material that is right in front of you doesn’t necessarily mean that you will be able to remember it later. Finally, beware of highlighting. A survey by Sarah Peterson (1992) found that 82 percent of students highlight study material, and most of them do so while they are reading the material for the first time. The problem with highlighting is that it seems like elaborative processing (you’re taking an active role in your reading by highlighting important points), but it often becomes automatic behavior that involves moving the hand, but with little deep thinking about the material. When Peterson compared comprehension for a group of students who highlighted and a group who didn’t, she found no difference between the performance of the two groups when they were tested on the material. Highlighting may be a good first step for some people, but it is usually important to go back over what you highlighted using techniques such as elaborative rehearsal or generating questions in order to get that information into your memory. Be An “Active” Note-Taker The preceding study suggestions are about how to study course material, which typically means studying a textbook, course readings, and lecture notes. In addition to following these suggestions, another way to improve course learning is to think about how you go about creating your lecture notes. Do you take notes by writing them out by hand or by typing them into your laptop? A majority of students report that they take notes on their laptop (Fried, 2008; Kay & Lauricella, 2011). When asked why they do this, their response is usually that typing notes on the laptop is more efficient, and that they can take more complete notes (Kay & Lauricella, 2011). Many professors, however, feel that taking notes on the laptop isn’t a good idea because the laptop creates the temptation to engage in distracting activities like surfing the web or sending texts or emails. But in addition to this distraction argument against laptops, there is another argument against computer note taking: Computer note taking can result in shallower processing of the material, and therefore poorer performance on exams. Empirical support for this idea has been provided by Pam Mueller and Daniel Oppenheimer (2014) in a paper titled “The Pen is Mightier Than the Keyboard: Advantages of Longhand Over Laptop Note Taking.” They ran a number of experiments in which they had students listen to lectures and take notes either by longhand or by using their laptop. Laptop note-takers took more notes, because laptop note taking is easier and faster than note taking by hand. In addition, there were two other differences. The laptop notes contained more word-for-word transcription of the lecture, and students in the laptop group performed worse than the longhand group when tested on the lecture material. Why did the laptop note-takers perform more poorly on the exam? Answering this question takes us back to the principle that memory for material depends on how it is encoded, and specifically that generating material yourself results in deeper processing and therefore better memory. According to Mueller and Oppenheimer, the shallow processing associated with simply transcribing what the professor is saying works against learning. Copyright 2019 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. WCN 02-200-202 08271_ch07_ptg01.indd 201 4/19/18 7:22 PM 202 CHAPTER 7 LTM: Encoding, Retrieval , and Consolidation In contrast, creating hand-written notes are more likely to involve synthesizing and summarizing the lecture, which results in deeper encoding and better learning. The bottom-line message of the Mueller and Oppenheimer paper is that “active” and “involved” note taking is better than “mindless transcribing.” Adam Putnam and coworkers (2016), in a paper titled “Optimizing Learning in College: Tips from Cognitive Psychology,” make many valuable suggestions regarding ways to succeed in college courses. Two of their suggestions, which are based on Mueller and Oppenheimer’s results, are that in lecture courses, (1) “leave your laptop at home,” to avoid the distraction of the Internet and social media, and (2) “write your notes instead of typing them,” because handwriting encourages more reflective, deeper processing. Of course, Mueller and Oppenheimer are just one source, so before writing off computer note taking, it might be best to wait for the results of more research. But whatever mechanism you use to take notes, do your best to take notes in your own words, without simply copying what the lecturer is saying. The message of all of these study hints is that there are ways to improve your learning by taking cues from the results of cognitive psychology research. The Putnam and coworkers, (2016) paper provides a concise summary of research-based conclusions about studying, and a paper by John Dunlosky and coworkers (2013) provides a more in-depth discussion, which ends by concluding that practice testing (see the upcoming section “Generate and Test”) and distributed practice (see the preceding section “Take Breaks”) are the two most effective study techniques. Retrieval: Getting Information Out of Memory We’ve already seen how retrieval can strengthen memory. But how can we increase the chances that something will be retrieved? The process of retrieval is extremely important because many of our failures of memory are failures of retrieval—the information is “in there,” but we can’t get it out. For example, you’ve studied hard for an exam but can’t come up with an answer when you’re taking the exam, only to remember it later after the exam is over. Or you unexpectedly meet someone you have previously met and can’t recall the person’s name, but it suddenly comes to you as you are talking (or, worse, after the person leaves). In both of these examples, you have the information you need but can’t retrieve it when you need it. Retrieval Cues When we discussed how remembering the word apple might serve as a retrieval cue for grape (page 195), we defined retrieval cues as words or other stimuli that help us remember information stored in our memory. As we now consider these cues in more detail, we will see that they can be provided by a number of different sources. An experience I had as I was preparing to leave home to go to class illustrates how location can serve as a retrieval cue. While I was in my office at home, I made a mental note to be sure to take the DVD on amnesia to school for my cognitive psychology class. A short while later, as I was leaving the house, I had a nagging feeling that I was forgetting something, but I couldn’t remember what it was. This wasn’t the first time I’d had this problem, so I knew exactly what to do. I returned to my office, and as soon as I got there I remembered that I was supposed to take the DVD. Returning to the place where I had originally thought about taking the disk helped me to retrieve my original thought. My office was a retrieval cue for remembering what I wanted to take to class. You may have had similar experiences in which returning to a particular place stimulated memories associated with that place. The following description by one of my students illustrates retrieval of memories of childhood experiences: Copyright 2019 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. WCN 02-200-202 08271_ch07_ptg01.indd 202 4/18/18 4:36 PM Retrieval : Getting Information Out of Memory 203 When I was 8 years old, both of my grandparents passed away. Their house was sold, and that chapter of my life was closed. Since then I can remember general things about being there as a child, but not the details. One day I decided to go for a drive. I went to my grandparents’ old house and I pulled around to the alley and parked. As I sat there and stared at the house, the most amazing thing happened. I experienced a vivid recollection. All of a sudden, I was 8 years old again. I could see myself in the backyard, learning to ride a bike for the first time. I could see the inside of the house. I remembered exactly what every detail looked like. I could even remember the distinct smell. So many times I tried to remember these things, but never so vividly did I remember such detail. (Angela Paidousis) My experience in my office and Angela’s experience outside her grandparents’ house are examples of retrieval cues that are provided by returning to the location where memories were initially formed. Many other things besides location can provide retrieval cues. Hearing a particular song can bring back memories for events you might not have thought about for years. Or consider smell. I once experienced a musty smell like the stairwell of my grandparents’ house and was instantly transported back many decades to the experience of climbing those stairs as a child. The operation of retrieval cues has also been demonstrated in the laboratory using a technique called cued recall. METHOD Cued Recall We can distinguish two types of recall procedures. In free recall, a participant is simply asked to recall stimuli. These stimuli could be words previously presented by the experimenter or events experienced earlier in the participant’s life. We have seen how this has been used in many experiments, such as the serial position curve experiment (page 164). In cued recall, the participant is presented with retrieval cues to aid in recall of the previously experienced stimuli. These cues are typically words or phrases. For example, Endel Tulving and Zena Pearlstone (1966) did an experiment in which they presented participants with a list of words to remember. The words were drawn from specific categories such as birds (pigeon, sparrow), furniture (chair, dresser), and professions (engineer, lawyer), although the categories were not specifically indicated in the original list. For the memory test, participants in the free recall group were asked to write down as many words as they could. Participants in the cued recall group were also asked to recall the words but were provided with the names of the categories, such as “birds,” “furniture,” and “professions.” The results of Tulving and Pearlstone’s experiment demonstrate that retrieval cues aid memory. Participants in the free recall group recalled 40 percent of the words, whereas participants in the cued recall group who had been provided with the names of categories recalled 75 percent of the words. One of the most impressive demonstrations of the power of retrieval cues was provided by Timo Mantyla (1986), who presented his participants with a list of 504 nouns, such as banana, freedom, and tree. During this study phase, participants were told to write three words they associated with each noun. For example, three words for banana might be yellow, bunches, and edible. In the test phase of the experiment, these participants were presented with the three words they had generated (self-generated retrieval cues) for half the nouns, or with three words that someone else had generated (other-person-generated retrieval cues) for the other half of the nouns. Their task was to remember the noun they had seen during the study phase. The results indicated that when the self-generated retrieval cues were presented, participants remembered 91 percent of the words (top bar in Figure 7.7), but when the Copyright 2019 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. WCN 02-200-202 08271_ch07_ptg01.indd 203 4/18/18 4:36 PM 204 CHAPTER 7 LTM: Encoding, Retrieval , and Consolidation Remembered nouns using self-generated retrieval cues. 91 Remembered nouns using other-person-generated retrieval cues. Never saw nouns; presented with other-person-generated retrieval cues. 55 17 20 40 60 80 100 Percent words ➤ Figure 7.7 Results of Mantyla’s (1986) experiment. Memory was best when retrieval cues were created by the participant (top bar), and not as good when retrieval cues were created by someone else (middle bar). Control participants who tried to guess the words based on retrieval cues generated by someone else did poorly (bottom bar). other-person-generated retrieval cues were presented, participants remembered only 55 percent of the words (second bar in Figure 7.7). You might think it would be possible to guess banana from three properties like yellow, bunches, and edible, even if you had never been presented with the word banana. But when Mantyla ran another control group in which he presented the cue words generated by someone else to participants who had never seen the 504 nouns, these participants were able to determine only 17 percent of the nouns. The results of this experiment demonstrate that retrieval cues (the three words) provide extremely effective information for retrieving memories, but that retrieval cues are significantly more effective when they are created by the person whose memory is being tested. (Also see Wagenaar, 1986, which describes a study in which Wagenaar was able to remember almost all of 2,400 diary entries he kept over a 6-year period by using retrieval cues.) Matching Conditions of Encoding and Retrieval The retrieval cues in the two experiments we just described were verbal “hints”—category names like “furniture” in the Tulving and Pearlstone experiment and three-word descriptions created by the participants in the Mantyla experiment. But we have also seen another kind of “hint” that can help with retrieval: returning to a specific location, such as Angela’s grandparents’ house or my office. Let’s consider what happened in the office example, in which I needed to return to my office to retrieve my thought about taking a DVD to class. The key to remembering the DVD was that I retrieved the thought “Bring the DVD” by returning to the place where I had originally encoded that thought. This example illustrates the following basic principle: Retrieval can be increased by matching the conditions at retrieval to the conditions that existed at encoding. We will now describe three specific situations in which retrieval is increased by matching conditions at retrieval to conditions at encoding. These different ways to achieve matching are (1) encoding specificity—matching the context in which encoding and retrieval occur; (2) state-dependent learning—matching the internal mood present during encoding and retrieval; and (3) transfer-appropriate processing—matching the task involved in encoding and retrieval. Encoding Specificity The principle of encoding specificity states that we encode information along with its context. For example, Angela encoded many experiences within the context of her grandparents’ house. When she reinstated this context by returning to the house many years later, she remembered many of these experiences. A classic experiment that demonstrates encoding specificity is D. R. Godden and Alan Baddeley’s (1975) “diving experiment.” In this experiment, one group of participants put on diving equipment and studied a list of words underwater, and another group studied the words on land (Figure 7.8a). These groups were then divided so that half the participants in the land and water groups were tested for recall on land and half were tested underwater. The results, indicated by the numbers, show that the best recall occurred when encoding and retrieval occurred in the same location. Copyright 2019 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. WCN 02-200-202 08271_ch07_ptg01.indd 204 4/18/18 4:36 PM Retrieval : Getting Information Out of Memory The results of the diving study, and many others, suggest that a good strategy for test taking would be to study in an environment similar to the environment in which you will be tested. Although this doesn’t mean you necessarily have to do all of your studying in the classroom where you will be taking the exam, you might want to duplicate in your study situation some of the conditions that will exist during the exam. This conclusion about studying is supported by an experiment by Harry Grant and coworkers (1998), using the design in Figure 7.8b. Participants read an article on psychoimmunology while wearing headphones. The participants in the “quiet” condition heard nothing in the headphones. Participants in the “noise” condition heard a tape of background noise recorded during lunchtime in a university cafeteria (which they were told to ignore). Half the participants in each group were then given a shortanswer test on the article under the quiet condition, and the other half were tested under the noise condition. The results, shown in Figure 7.8b, indicate that participants did better when the testing condition matched the study condition. Because your next cognitive psychology exam will take place under quiet conditions, it might make sense to study under quiet conditions. (Interestingly, a number of my students report that having outside stimulation such as music or television present helps them study. This idea clearly violates the principle of encoding specificity. Can you think of some reasons that students might nonetheless say this?) STUDY TEST (a) Underwater TEST (b) On land Underwater On land 11.5 8.5 9.05 13.5 Noise Quiet Noise Quiet Noise Quiet 6.2 5.4 4.6 6.7 STUDY TEST On land Underwater STUDY Sad Sad 205 Happy Happy Sad Happy 27 17 17 32 State-Dependent Learning Another example of how (c) matching the conditions at encoding and retrieval can influence memory is state-dependent learning—learning that is associated with a particular internal state, such as mood ➤ Figure 7.8 Design and results for (a) Godden and Baddeley’s (1975) “diving” experiment; (b) Grant et al.’s (1998) “studying” or state of awareness. According to the principle of stateexperiment; (c) Eich and Metcalfe’s (1989) “mood” experiment. dependent learning, memory will be better when a person’s Results for each test condition are indicated by the number directly internal state (mood or awareness) during retrieval matches under that condition. The matching colors (light green to dark his or her internal state during encoding. For example, Eric green, and light orange to dark orange) indicate situations in which Eich and Janet Metcalfe (1989) demonstrated that memory study and test conditions matched. is better when a person’s mood during retrieval matches his or her mood during encoding. They did this by asking participants to think positive thoughts while listening to “merry” or happy music, or depressing thoughts while listening to “melancholic” or sad music (Figure 7.8c). Participants rated their mood while listening to the music, and the encoding part of the experiment began when their rating reached “very pleasant” or “very unpleasant.” Once this occurred, usually within 15 to 20 minutes, participants studied lists of words while in their positive or negative mood. After the study session ended, the participants were told to return in 2 days (although those in the sad group stayed in the lab a little longer, snacking on cookies and chatting with the experimenter while happy music played in the background, so they wouldn’t leave the laboratory in a bad mood). Two days later, the participants returned, and the same procedure was used to put them in a positive or negative mood. When they reached the mood, they were given a memory test for the words they had studied 2 days earlier. The results, Copyright 2019 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. WCN 02-200-202 08271_ch07_ptg01.indd 205 4/18/18 4:36 PM 206 CHAPTER 7 LTM: Encoding, Retrieval , and Consolidation shown in Figure 7.8c, indicate that they did better when their mood at retrieval matched their mood during encoding (also see Eich, 1995). The two ways of matching encoding and retrieval that we have described so far have involved matching the physical situation (encoding specificity) or an internal feeling (state-dependent learning). Our next example involves matching the type of cognitive task at encoding and retrieval. Matching the Cognitive Task: Transfer-Appropriate Processing Donald Morris and coworkers (1977) did an experiment that showed that retrieval is better if the same cognitive tasks are involved during both encoding and retrieval. The procedure for their experiment was as follows: Part I. Encoding Participants heard a sentence with one word replaced by “blank,” and 2 seconds later they heard a target word. There were two encoding conditions. In the meaning condition, the task was to answer “yes” or “no” based on the meaning of the word when it filled in the blank. In the rhyming condition, participants answered “yes” or “no” based on the sound of the word. Here are some examples: Meaning Condition 1. Sentence: The blank had a silver engine. Target word: train Correct answer: “yes” 2. Sentence: The blank walked down the street. Target word: building Correct answer: “no” Rhyming Condition 1. Sentence: Blank rhymes with pain. Target word: Train Correct answer: “yes” 2. Sentence: Blank rhymes with car. Target word: Building Correct answer: “no” The important thing about these two groups of participants is that they were asked to process the words differently. In one case, they had to focus on the word’s meaning to answer the question, and in the other case they focused on the word’s sound. Part II. Retrieval The question Morris was interested in was how the participants’ ability to retrieve the target words would be affected by the way they had processed the words during the encoding part of the experiment. There were a number of different conditions in this part of the experiment, but we are going to focus on what happened when participants were required to process words in terms of their sounds. Participants in both the meaning group and the rhyming group were presented with a series of test words, one by one. Some of the test words rhymed with target words presented during encoding; some did not. Their task was to answer “yes” if the test word rhymed with one of the target words and “no” if it didn’t. In the examples below, notice that the test words were always different from the target word. Test word: rain Answer: Test word: street Answer: “yes” (because it rhymes with the previously presented target word train) “no” (because it doesn’t rhyme with any of the target words that were presented during encoding) The key result of this experiment was that the participants’ retrieval performance depended on whether the retrieval task matched the encoding task. As shown in Copyright 2019 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. WCN 02-200-202 08271_ch07_ptg01.indd 206 4/18/18 4:36 PM Retrieval : Getting Information Out of Memory 207 Figure 7.9, participants who had focused on rhyming during encod- Encoding Retrieval ing remembered more words in the rhyming test than participants who had focused on meaning. Thus, participants who had focused on the Rhyming Rhyming-based Rhyming 49% word’s sound during the first part of the experiment did better when encoding test task the test involved focusing on sound. This result—better performance when the type of processing matches in encoding and retrieval—is called transfer-appropriate processing. Rhyming Meaning-based Meaning 33% Transfer-appropriate processing is like encoding specificity and encoding test task state-dependent learning because it demonstrates that matching conditions during encoding and retrieval improves performance. But, in addition, the result of this experiment has important implications for the ➤ Figure 7.9 Design and results for the Morris et al. (1977) experiment. Participants who did a rhyminglevels of processing theory discussed earlier. Remember that the main based encoding task did better on the rhyming test idea behind levels of processing theory is that deeper processing leads than participants who did a meaning-based encoding to better encoding and, therefore, better retrieval. Levels of processing task. This result would not be predicted by levels of theory would predict that participants who were in the meaning group processing theory but is predicted by the principle that during encoding would experience “deeper” processing, so they should better retrieval occurs if the encoding and retrieval tasks perform better. Instead, the rhyming group performed better. Thus, in are matched. addition to showing that matching the tasks at encoding and retrieval is important, Morris’s experiment shows that deeper processing at encoding does not always result in better retrieval, as proposed by levels of processing theory. Our approach to encoding and retrieval has so far focused on behavioral experiments that consider how conditions of encoding and retrieval affect memory. But there is another approach to studying encoding and retrieval that focuses on physiology. In the rest of this chapter, we will look “under the hood” of memory to consider how physiological changes that occur during encoding influence our ability to retrieve memory for an experience later. T E ST YOUR SELF 7.2 1. Describe the following five ways of improving the effectiveness of studying: (1) elaborate; (2) generate and test; (3) organize; (4) take breaks; (5) avoid “illusions of learning.” How does each technique relate to findings about encoding and retrieval? 2. What does it mean to be an “active” learner? How is this question related to the difference between taking notes by hand versus note taking on a laptop? 3. Retrieval cues are a powerful way to improve the chances that we will remember something. Why can we say that memory performance is better when you use a word in a sentence, create an image, or relate it to yourself, which are all techniques involving retrieval cues? 4. What is cued recall? Compare it to free recall. 5. Describe the Tulving and Pearlstone cued recall experiment and Mantyla’s experiment in which he presented 600 words to his participants. What was the procedure and what was the result for each experiment, and what does each tell us about retrieval? 6. What is encoding specificity? Describe Baddeley and Godden’s “diving” experiment and Grant’s studying experiment. What does each one illustrate about encoding specificity? About