Memory Errors, Memory Gaps Where did you spend last summer? What country did you grow up in? Where were you five minutes ago? These are easy questions, and you effortlessly retrieve this information from memory the moment you need it. If we want to understand how memory functions, therefore, we need to understand how you locate these bits of information (and thousands of others just like them) so readily.
But we also need to account for some other observations. Sometimes, when you try to remember an episode, you draw a blank. On other occasions, you recall something, but with no certainty that you're correct: "I think her nickname was Dink, but I'm not sure." And sometimes, when you do recall a past episode, it turns out that your memory is mistaken. Perhaps a few details of the event were different from the way you recall them. Or perhaps your memory is completely wrong, misrepresenting large elements of the original episode. Worse, in some cases you can remember entire events that never happened at all! In this chapter, well consider how, and how often, these errors arise. Let's start with some examples. Memory Errors: Some Initial Examples In 1992, an El Al cargo plane lost power in two of its engines just after taking off from Amsterdam's Schiphol Airport. The pilot attempted to return the plane to the airport but couldn't make it. A few minutes later, the plane crashed into an 11-story apartment building in Amsterdam's Bijlmermeer neighborhood. The building collapsed and burst into flames; 43 people were killed, including the plane's entire crew.
Ten months later, researchers questioned 193 Dutch people about the crash, asking them in particular, "Did you see the television film of the moment the plane hit the apartment building?" More than half of the participants (107 of them) reported seeing the film, even though there was no such film. No camera had recorded the crash; no film (or any reenactment) was shown on television. The participants seemed to be remembering something that never took place (Crombag, Wagenaar, & van Koppen, 1996).
In a follow-up study, investigators surveyed another 93 people about the plane crash. These people were also asked whether they'd seen the (nonexistent) TV film, and then they were asked detailed questions about exactly what they had seen in the film: Was the plane burning when it crashed, or did it catch fire a moment later? In the film, did they see the plane come down vertically or did it hit the building while still moving horizontally at a considerable with no forward speed speed? Two thirds of these participants reported seeing the film, and most of them were able to provide details about what they had When asked about the plane's speed, for example, only 23% said that they couldn't remember. The others gave various responses, presumably based on their "memory" of the (nonexistent) film.
Other studies have produced similar results. There was no video footage of the car crash in which Princess Diana was killed, but 44% of the British participants in one study recalled seeing the footage (Ost, Vrij, Costall, & Bull, 2002). More than a third of the participants questioned about a nightclub bombing in Bali recalled seeing a (nonexistent) video, and nearly all these participants reported details about what they'd seen in the video (Wilson & French, 2006).
It turns out that more persistent questioning can lead some of these people to admit they actually don't remember seeing the video. Even with persistent questioning, though, many participants continue to insist that they did see the video-and they offer additional information in the film (e.g., Patihis & Loftus, 2015; Smeets et al., 2006). Also, in all about exactly what they sav these studies, let's emphasize that participants are thinking back to an emotional and much- discussed event; the researchers aren't asking them to recall a minor occurrence.
Is memory more accurate when the questions come after a shorter delay? In a study by Brewer and Treyens (1981), participants were asked to wait briefly in the experimenter's office prior to the procedure's start. After 35 seconds, participants were taken out of this office and told that there actually was no experimental procedure. Instead, the study was concerned with their memory for the room in which they'd just been sitting. Participants' descriptions of the office were powerfully influenced by their prior beliefs. Surely, most participants would expect an academic office to contain shelves filled with books. In this particular office, though, no books in view (see Fiqure 8.1). Even so, almost one third of the participants (9 of 30) reported seeing books in the office. Their recall, in other words, was governed by their expectations, not by reality. How could this happen? How could so many Dutch participants be wrong in their recall of the plane crash? How could intelligent, alert college students fail to remember what they'd seen in an office just moments earlier? Memory Errors: A Hypothesis In Chapters 6 and 7, we emphasized the importance of memory connections that link each bit of knowledge in your memory to other bits. Sometimes these connections tie together similar episodes, so that a trip to the beach ends up connected in memory to your recollection of other trips. Sometimes the connections tie an episode to certain ideas-ideas, perhaps, that were part of your understanding of the episode, or ideas that were triggered by some element within the episode.
It's not just separate episodes and ideas that are linked in this way. Even for a single episode, the elements of the episode are stored separately from one another and are linked by connections. In fact, the storage is "modality-specific," with the bits representing what you saw stored in brain areas devoted to visual processing, the bits representing what you heard stored in brain areas specialized for auditory processing, and so on (e.g., Nyberg, Habib, McIntosh, & Tulving, 2000; Wheeler Peterson, & Buckner, 2000; also see Chapter 7, Figure 7.4, p. 245).
With all these connections in place-element to element, episode to episode, episode to related ideas-information ends up stored in memory in a system that resembles a vast spider web, with was the each bit of information connected by many threads to other bits elsewhere in the web. This idea that in Chapter 7 we described as a huge network of interconnected nodes. However, within this network there are no boundaries keeping the elements of one episode separate from elements of other episodes. The episodes, in other words, aren't stored in separate "files," each distinct from the others. What is it, therefore, that holds together the various bits within each episode? To a large extent, it's simply the density of connections. There are many connections linking the various aspects of your "trip to the beach" to one another; there are fewer connections linking this event to other events.
As we've discussed, these connections play a crucial role in memory retrieval. Imagine that you're trying to recall the restaurant you ate at during your beach trip. You'll start by activating nodes in memory that represent some aspect of the trip-perhaps your memory of the rainy weather. Activation will then flow outward from there, through the connections you've established, and this will energize nodes representing other aspects of the trip. The flow of activation can then continue from there, eventually reaching the nodes you seek. In this way, the connections serve as retrieval paths, guiding your search through memory.
Obviously, then, memory connections are a good thing; without them, you might never locate the information you're seeking. But the connections can also create problems. As you add more and more links between the bits of this episode and the bits of that episode, you're gradually knitting these two episodes together. As a result, you may lose track of the "boundary" between the episodes. More precisely, you're likely to lose track of which bits of information were contained within which event. In this way, you become vulnerable to what we might think of as "transplant" errors, in which a bit of information encountered in one context is transplanted into another context. In the same way, as your memory for an episode becomes more and more interwoven with other thoughts you've had about the event, it will become difficult to keep track of which elements are were actually part of the episode itself, and which are linked merely because they were associated with the episode in your thoughts. This, too, can produce linked to the episode because they transplant errors, in which elements that were part of your thinking get misremembered as if they were actually part of the original experience. Understanding Both Helps and Hurts Memory It seems, then, that memory connections both help and hurt recollection. They help because the connections, serving as retrieval paths, enable you to locate information in memory. But connections can hurt because they sometimes make it difficult to see where the remembered episode stops and other, related knowledge begins. As a result, the connections encourage intrusion errors-errors in which other knowledge intrudes into the remembered event.
To see how these points play out, consider an early study by Owens, Bower, and Black (1979). In this study, half of the participants read the following passage:
Nancy arrived at the cocktail party. She looked around the room to see who was there. She went to talk with her professor. She felt she had to talk to him but was a little nervous about just what to say. A group of people started to play charades. Nancy went over and had some refreshments. The hors d'oeuvres were good, but she wasn't interested in talking to the rest of the people at the party. After a while she decided she'd had enough and left the party.
Other participants read the same passage, but with a prologue that set the stage:
Nancy woke up feeling sick again, and she wondered if she really was pregnant. How would she tell the professor she had been seeing? And the money was another problem.
All participants were then given a recall test in which they were asked to remember the sentences as exactly as they could. Table 8.1 shows the results-the participants who had read the prologue (the Theme condition) recalled much more of the original story (i.e., they remembered the propositions actually contained within the story). This is what we should expect, based on the claims made in Chapter 6: The prologue provided a meaningful context for the remainder of the story, and this helped understanding. Understanding, in turn, promoted recall.
At the same time, the story's prologue also led participants to include elements in their recall that weren't mentioned in the original episode. In fact, participants who had seen the prologue made four times as many intrusion errors as did participants who hadn't seen the prologue. For example, they might include in their recall something like "The professor had gotten Nancy pregnant." This idea isn't part of the story but is certainly implied, so will probably be part of participants' understanding of the story. It's then this understanding (including the imported element) that is remembered. The DRM Procedure Similar effects, with memory connections both helping and hurting memory, can be demonstrated with simple word lists. For example, in many experiments, participants have been presented with lists like this one: "bed, rest, awake, tired, dream, wake, snooze, blanket, doze, slumber, snore, nap, peace, yawn, drowsy." Immediately after hearing this list, are asked to recall as many of participants the words as they can.
As you surely noticed, the words in this list are all associated with sleep, and the presence of this theme helps memory: The list words are easy to remember. It turns out, though, that the word "sleep" is not itself included in the list. Nonetheless, research participants spontaneously make the connection between the list words and this associated word, and this connection almost always leads to a memory error. When the time comes for recall, participants are extremely likely to recall that they heard "sleep." In fact, they're just as likely to recall "sleep" as they are to recall the actual words on the list (see Figure 8.2). When asked how confident they are in their memories participants are just as confident in their (false) recall of "sleep" as they are in their (correct) memory of genuine list words (Gallo, 2010: for earlier and classic papers in this arena. see Deese, 1957; Roediger & McDermott, 1995, 2000). This experiment (and many others like it) uses the DRM procedure, a bit of terminology that honors the investigators who developed it (James Deese, Henry Roediger II, and Kathleen McDermott). The procedure yields many errors even if participants are put on their guard before the procedure begins-that is, told about the nature of the lists and the frequency with which they produce errors (Gallo, Roberts, & Seamon, 1997; McDermott & Roediger, 1998). Apparently, the mechanisms leading to these errors are so automatic that people can't inhibit them. Schematic Knowledge Imagine that you go to a restaurant with a friend. This setting is familiar for you, and you have some commonsense knowledge about what normally happens here. You'll be seated; someone will bring menus; you'll order, then eat; eventually, you'll pay and leave. Knowledge like this is often referred to with the Greek word schema (plural: schemata). Schemata summarize the broad pattern of what's normal in a situation-and so your kitchen schema tells you that a kitchen is likely to have a stove but no piano; your dentist's office schema tells you that there are likely to be magazines in the waiting room, that you'll probably get a new toothbrush when you leave, and so on.
Schemata help you in many ways. In a restaurant, for example, you're not puzzled when someone keeps filling your water glass or when someone else drops by to ask, "How is everything?" Your schema tells you that these are normal occurrences in a restaurant, and you instantly understand how they fit into the broader framework. Schemata also help when the time comes to recall how an event unfolded. This is because there are often gaps in your recollection-either because you didn't notice certain things in the first place, or because you've gradually forgotten some aspects of the experience. (We'll say more about forgetting later in the chapter.) In either case, you can rely on your schemata to fill in these gaps. So, in thinking back to your dinner at Chez Pierre, you might not remember anything about the menus. Nonetheless, you can be reasonably sure that there were menus and that they were given to you early on and taken away after you placed your order. On this basis, you're likely to include menus within your "recall" of the dinner, even if you have no memory of seeing the menus for this particular meal. In other words, you'll supplement what you actually remember with a plausible reconstruction based on your schematic knowledge. And in most cases this after-the-fact reconstruction will be correct, since schemata do, after all, describe what happens most of the time. Evidence for Schematic Knowledge Clearly, then, schematic knowledge helps you, by guiding your understanding and enabling you to reconstruct things you can't remember. But schematic knowledge can sometimes hurt you, by promoting errors in perception and memory. Moreover, the types of errors produced by schemata are quite predictable. As an example, imagine that you visit a dentist's office, and this one happens not to have any magazines in the waiting room. It's likely that you'll forget this detail after a while, so what will happen when you later try to recall your trip to the dentist? Odds are good that you'll rely on schematic knowledge and "remember" that there were magazines (since, after all, there usually are some scattered around a waiting room). In this way, your recollection will make this dentist's office seem more typical, more ordinary, than it actually was. Here's the same point in more general terms. We've already said that schemata tell you what's typical in a setting. Therefore, if you rely on schematic knowledge to fill gaps in your recollection, you'll fill those gaps with what's normally in place in that sort of situation. As a result, any reliance on schemata will make the world seem more "normal" than it really is and will make the past seem more "regular" than it actually was.
This tendency toward "regularizing" the past has been documented in many settings. The classic demonstration, however, comes from studies published long ago by British psychologist Frederick Bartlett. Bartlett presented his participants with a story taken from the folklore of Native Americans (Bartlett, 1932). When tested later, the participants did reasonably well in recalling the gist of the story, but they made many errors in recalling the particulars. The pattern of errors, though, was quite systematic: The details omitted tended to be ones that made little sense to Bartlett's British participants. Likewise, aspects of the story that were unfamiliar were often changed into aspects that were more familiar; steps of the story that seemed inexplicable were supplemented to make the story seem more logical.
Overall, then, the participants' memories seem to have "cleaned up" the story they had read- making it more coherent (from their perspective), more sensible. This is exactly what we would expect if the memory errors derived from the participants' attempts to understand the story and with that, their efforts toward fitting the story into a schematic frame. Elements that fit within the frame remained in their memories (or could be reconstructed later). Elements that didn't fit dropped out of memory or were changed. the same spirit, consider the Brewer and Treyens study mentioned at the start of this chapter- the study in which participants remembered seeing shelves full of books, even though there were none. This error was produced by schematic knowledge. During the event itself (while the participants were sitting in the office), schematic knowledge told the participants that academic offices usually contain many books, and this knowledge biased what the participants paid attention to. (If you're already certain that the shelves contain books, why should you spend time looking at the shelves? This would only confirm something you already know-see Vo & Henderson, 2009.) Then, when the time came to recall the office, participants used their schema to reconstruct what the office must have contained- a desk, a chair, and of course lots of books. In this way, the memory for the actual office was eclipsed by generic knowledge about what a "normal" academic office contains.
Likewise, think back to the misremembered plane crash and the related studies of people remembering videos of other prominent events, even though there were no videos of these events. Here, too, the memory errors distort reality by making the past seem more regular, more typical, than it really was. After all, people often hear about major news events via a television broadcast or Internet coverage, and these reports usually include vivid video footage. So here, too, the past as remembered seems to have been assimilated into the pattern of the ordinary. The event as it unfolded was unusual, but the event as remembered becomes typical of its kind-just as we would expect if understanding and remembering were guided by our knowledge of the way things generally unfold. e. Demonstration 8.1: Associations and Memory Error This is a test of immediate memory. Read List 1; then close the list and try to write down, from memory, as many words as you can remember from the list. Then expand the list to read List 2, close the list, and try to write down as many of its words as you can remember. Then do the same for List 3. When you're all done, read the material that follows.
List 1 List 2 List 3
Door Nose Sour
Glass Breathe Candy
Pane Sniff Sugar
Shade Aroma Bitter
Ledge Hear Good
Sill See Taste
House Nostril Tooth
Open Whiff Nice
Curtain Scent Honey
Frame Reek Soda
View Stench Chocolate
Breeze Fragrance Heart
Sash Perfume Cake
Screen Salts Tart
Shutter Rose Pie Don't read beyond this point until you've tried to recall each of the three lists!
Each of these lists is organized around a theme, but the word that best captures that theme included in the list. All of the words in List 1, for example, are strongly associated with the word "window" but that word is not in the list. All of the words in List 2 are strongly associated with "smell" and all in List 3 are strongly associated with "sweet"; but again, these theme words are not in the lists. In your recall of the lists, did you include seeing "window" in List 1? "Smell" in List 2? "Sweet" in List 3?
This procedure, described in the chapter, is called the DRM procedure, in honor of the researchers who have developed this paradigm (Deese, Roediger, and McDermott). IIn this situation, often as many as half of the people tested do make these specific errors-and with considerable confidence. Of course, the theme words are associated with the list in your memory, and it's this association that leads many people into a memory error.
Perhaps you read through the material after reading the text's description of the DRM procedure. Did you make the expected error anyway? Research suggests that these errors appear even when research participants are warned about the DRM pattern, just as you were. Did you show that pattern? Or did you manage to avoid the errors?
Demonstration adapted from McDermott, K., & Roediger, H. (1998). False recognition of associates can be resistant to an explicit warning to subjects and an immediate recognition probe. Journal of Memory and Language, 39, 508-520. See also Roediger, H., &McDermott, K. (1995). Creating false memories: Remembering words not presented in lists. Journal of Experimental Psychology: Learning, Memory and Cognition, 21(4), 803-814. The Cost of Memory Errors There's clearly a "good news, bad news" quality to our discussion so far. On the positive side, memory connections serve as retrieval paths, allowing you to locate information in storage. The connections also enrich your understanding, because they tie each of your memories into a context provided by other things you know. In addition, links to schematic knowledge enable you to supplement your perception and recollection with well-informed (and usually accurate) inference.
On the negative side, though, the same connections can undermine memory accuracy, and memory errors are troubling. As we've discussed in other contexts, you rely on memory in many aspects of life, and it's unsettling that the memories you rely on may be wrong-misrepresenting how the past unfolded.
Eyewitness Errors In fact, we can easily find circumstances in which memory errors are large in scale (not just concerned with minor details in the episode) and deeply consequential. For example, errors in eyewitness testimony (e.g., identifying the wrong person as the culprit or misreporting how an event unfolded) can potentially send an innocent person to jail and allow a guilty person to go free.
How often do eyewitnesses make mistakes? One answer comes from U.S. court cases in which DNA evidence, not available at the time of the trial, shows that the courts had convicted people who were, in truth, not guilty. There are now more than 350 of these exonerations, and the exonerees had (on average) spent more than a dozen years in jail for crimes they didn't commit. Many of them were on death row, awaiting execution. When closely examined, these cases yield a clear message. Some of these men and women of dishonest because convicted were informants; some because analyses of forensic evidence had been botched. But by far the most common concern is eyewitness errors. In fact, according to most analyses, eyewitness errors account for at least three quarters of these false convictions-more than all other causes combined (e.g., Garrett, 2011; Reisberg, 2014)
Cases like these make it plain that memory errors, including misidentifications, are profoundly important. We're therefore led to ask: Are there ways to avoid these errors? Or are there ways to detect the errors, so that we can decide which memories are correct and which ones are not? Planting False Memories An enormous number of studies have examined eyewitness memory-the sort of memory that police rely on when investigating crimes. In one of the earliest procedures, Loftus and Palmer (1974) showed participants series of pictures depicting an automobile collision. Later, participants were asked questions about the collision, but the questions were phrased in different ways for different groups. Some participants were asked, for example, "How fast were the cars going when they hit each other?" A different group was asked, "How fast were the cars going when they smashed into each other?" The differences among these questions were slight, but had a substantial influence: Participants in the "hit" group estimated the speed to have been 34 miles per hour: those in the "smashed" group estimated 41 miles per hour-20% higher (see Figure 8.3). But what is critical comes next: One week later, the participants were asked in a perfectly neutral way whether they had seen any broken glass in the pictures. Participants who had initially been asked the "hit" question tended to remember (correctly) that no glass was visible; participants who had been asked the "smashed" question, though, often made this error. It seems, therefore, that the change of just one word within the initial question can have a significant effect-in this case, more than doubling the likelihood of memory error.
In other studies, participants have been asked questions that contain overt misinformation about an event. For example, they might be asked, "How fast was the car going when it raced by the barn?" when, in truth, no barn was in view. In still other studies, participants are exposed to descriptions of the target event allegedly written by "other witnesses." They might be told, for example, "Here's how someone else recalled the crime; does this match what you recall?"" Of course, the "other witness" descriptions contained some misinformation, enabling researchers to determine if participants "pick up" the false leads (e.g., Paterson & Kemp, 2006; also Edelson, Sharon, Dolan, & Dudai, 2011). In other studies, researchers ask questions that require the participants themselves to make up some bit of misinformation. For example, participants could be asked, "In the video, was the man bleeding from his knee or from his elbow after the fall?" Even though it was clear in the video that the man wasn't bleeding at all, participants are forced to choose one of the two options (e.g., Chrobak & Zaragoza, 2008; Zaragoza, Payment, Ackil, Drivdahl, & Beck, 2001). These procedures differ in important ways, but they are all variations on the same theme. In each case, the participant experiences an event and then is exposed to a misleading suggestion about how the event unfolded. Then some time is allowed to pass. At the end of this interval, the participant's memory is tested. And in each of these variations, the outcome is the same: A substantial number of participants-in some studies, more than one third-end up incorporating the false suggestion into their memory of the original event.
Of course, some attempts at manipulating memory are more successful, some less so. It's easier, for example, to plant plausible memories rather than implausible ones. (However, memories for implausible events can also be planted-see Hyman, 2000; Mazzoni, Loftus, & Kirsch, 2001; Pezdek Blandon-Gitlin, & Gabbay, 2006; Scoboria, Mazzoni, Kirsch, & Jimenez, 2006; Thomas & Loftus, 2002.) Errors are also more likely if the post-event information supplements what the person remembers, in comparison to contradicting what the person would otherwise remember. It's apparently easier, therefore, to "add to" a memory than it is to "replace" a memory (Chrobak & Zaragoza, 2013). False memories are also more easily planted if the research participants don't just hear about the false event but, instead, are urged to imagine how the suggested event unfolded. In one study, participants were given a list of possible childhood events (going to the emergency room late at night; winning a stuffed animal at a carnival; getting in trouble for calling 911) and were asked to "picture each event as clearly and completely" as they could. This simple exercise was enough to increase participants' confidence that the event had really occurred (Garry, Manning, Loftus, & Serman. 1996; also Mazzoni & Memon, 2003; Sharman & Barnier, 2008; Shidlovski, Schul. & Mayo. 2014). Even acknowledging these variations, though, let's emphasize the consistency of the findings. We can use subtle procedures (with slightly leading questions) to plant false information in someone's memory, or we can use a more blatant procedure (demanding that the person make up the bogus facts). We can use pictures, movies, or live events as the to-be-remembered materials. In all cases it's remarkably easy to alter someone's memory, with the result that the past as the person remembers it can differ markedly from the past as it really was. This is a widespread pattern, with numerous implications for how we think about the past and how we think about our reliance on our own memories. (For more on research in this domain, see Carpenter & Schacter, 2017; Cochran, Greenspan, Bogart, & Loftus, 2016; Frenda, Nichols, & Loftus, 2011; Laney, 2012; Loftus, 2017; Rich & Zaragoza, 2016. For research documenting similar memory errors in children, see, e.g., Bruck & Ceci, 1999, 2009; Reisberg, 2014.)
Are There Limits on the Misinformation Effect? The studies just described reflect the misinformation effect-a term referring to memory errors that result from misinformation received after an event was experienced. What sorts of memory errors can be planted in this way?
We've mentioned studies in which participants remember broken glass when really there was none or remember a barn when there was no barn in view. Similar procedures have altered how people are remembered-and so, with just a few "suggestions" from the experimenter, participants remember clean-shaven men as bearded, young people as old. and fat people as thin (e.g.. Christiaansen, Sweeney, & Ochalek, 1983; Frenda et al., 2011). It's remarkably easy to produce these errors-with just one word ("hit" vs. "smashed") being enough to alter an individual's recollection. What happens, though, if we ramp up our efforts to plant false memories? Can we create larger-scale errors? In one study, college students were told that the investigators were trying to learn how different people remember the same experience. The students were then given a list of events that (they were told) had been reported by their parents; the students were asked to recall these events as well as they could, so that the investigators could compare the students' recall with their parents' (Hyman, Husband, & Billings, 1995).
Some of the events on the list actually had been reported by the participants' parents. Other events were bogus-made up by the experimenters. One of the bogus events was an overnight hospitalization for a high fever; in a different experiment, the bogus event was attending a wedding reception and accidentally spilling a bowlful of punch on the bride's family.
The college students were easily able to remember the genuine events (i.e.., the events actually reported by their parents). In an initial interview, more than 80 % of these events were recalled, but none of the students recalled the bogus events. However, repeated attempts at recall changed this pattern. By a third interview, 25% of the participants were able to remember the embarrassment of spilling the punch, and many were able to supply the details of this (entirely fictitious) episode. Other studies have shown similar results. Participants have been led to recall details of particular birthday parties that, in truth, they never had (Hyman et al., 1995); or an incident of being lost in a shopping mall even though this event never took place; or a (fictitious) event in which they were the victim of a vicious animal attack (Loftus, 2003, 2004; also see, e.g. Chrobak & Zaragoza, 2008 Geraerts et al., 2009: Laney & Loftus, 2010). Errors Encouraged through "Evidence" Other researchers have taken a further step and provided participants with "evidence" in support of the bogus memory. In one procedure, researchers obtained a real childhood snapshot of the participant (see Figure 8.4A for an example) and, with a few clicks of a computer mouse, created a fictitious picture like the one shown in Figure 8.4B. With this prompt, many participants were led to a vivid, detailed recollection of the hot-air balloon ride-even though it never occurred (Wade, Garry, Read, & Lindsay, 2002). Another study used an unaltered photo showing the participants' second- grade class (see Figure 8.5 for an example). This was apparently enough to persuade participants that the experimenters really did have information about their childhood. Therefore, when the experimenters "reminded" the participants about an episode of their childhood misbehavior, the participants took this reminder seriously. The result: Almost 80% were able to "recall" the episode, often in detail, even though it had never happened (Lindsay, Hagen, Read, Wade, & Garry, 2004). False Memories, False Confessions
It is clear that people can sometimes remember entire events that never took place. They sometimes happened. They can remember emotional episodes (like being lost in a shopping mall) that never remember their own transgressions (spilling the punch bowl, misbehaving in the second grade), even though these misdeeds never occurred.
One study pushed things still further, using a broad mix of techniques to encourage false memories (Shaw & Porter, 2015). The interviewer repeatedly asked participants that (supposedly) she had learned about from their parents. She assured participants that she had detailed information about the (fictitious) event, and she applied social pressure with comments like to recall an event "Most people are able to retrieve lost memories if they try hard enough." She offered smiles and encouraging nods whenever participants showed signs of remembering the (bogus) target events. If participants couldn't recall the target events, she showed signs of disappointment and said things like "That's ok. Many people can't recall certain events at first because they haven't thought about them for such a long time." She also encouraged participants to use a memory retrieval technique (guided imagery) that is known to foster false memories. With these (and other) factors in play, Shaw and Porter persuaded many of their participants that just a few years earlier the participants had committed a crime that led to police contact. In fact, many participants seemed able to remember an episode in which they had assaulted another person with a weapon and had then been detained by the police. This felony never happened, but many participants "recalled" it anyhow. Their memories were in some cases vivid and rich with detail, and on many measures indistinguishable from memories known to be accurate.
Let's be clear, though, that this study used many forms of influence and encouragement. It takes a lot to pull memory this far off track! There has also been debate over just how many of the participants in this study truly developed false memories. Even so, the results show that it's possible for a large number of people to have memories that are emotionally powerful, deeply consequential, and utterly false. (For discussion of Shaw and Porter's study, see Wade, Garry, & Pezdek, 2017. Also see Brewin & Andrews, 2017, and then in response, Becker-Blease & Freyd, 2017; Lindsay & Hyman, 2017: McNally, 2017: Nash, Wade, Garry, Loftus, & Ost, 2017; Otgaar, Merckelbach, Jelicic, & Smeets 2017: and Scoboria & Mazzoni, 2017.) Avoiding Memory Errors Evidence is clear that people do make mistakes-at times, large mistakes-in remembering the past. But people usually don't make mistakes. In other words, you generally can trust your memory because more often than not your recollection is detailed, long-lasting, and correct. This mixed pattern, though, demands a question: Is there some way to figure out when you've made a memory mistake and when you haven't? Is there a way to decide which memories you can rely on and which ones you can't? Memory Confidence evaluating memories, people rely heavily on expressions of certainty or confidence. Specifically, people tend to trust memories that are expressed with confidence. ("I distinctly remember her yellow jacket; I'm sure of it.") They're more cautious about memories that are hesitant. ("I think she was wearing yellow, but I'm not certain.") We can see these patterns when people are evaluating their own memories (e.g.. when deciding whether to take action or not, based on a bit of recollection); we see the same patterns when people are evaluating memories they hear from someone else (e.g., when juries are deciding whether they can rely on an eyewitness's testimony). Evidence suggests, though, that a person's degree of certainty is an uneven indicator of whether a memory is trustworthy. On the positive side, there are circumstances in which certainty and highly correlated (e.g., Wixted, Mickes, Clark, Gronlund, & Roediger, 2015; easily find exceptions to this pattern- forget that day; I remember it memory accuracy are we can Wixted & Wells, 2017). On the negative side, though, including memories that are expressed with total certainty ("I'll never yesterday") but that turn out to be entirely mistaken. In fact, we can find though it were as circumstances in which there's no correspondence at all between how certain someone says she is, in recalling the past, and how accurate that recollection is likely to be. As a result, if we try to categorize memories as correct or incorrect based on someone's confidence, we'll often get it wrong. (For some of the evidence, see Busey, Tunnicliff, Loftus, & Loftus, 2000: Hirst et al., 2009: Neisser & Harsch, 1992; Reisberg, 2014; Wells & Quinlivan, 2009.) How can this be? One reason is that a person's confidence in a memory is often influenced by factors that have no impact on memory accuracy. When these factors are present, confidence can shift (sometimes upward, sometimes downward) with no change in the accuracy level, with the result that any connection between confidence and accuracy can be strained or even shattered.
Participants in one study witnessed a (simulated) crime and later were asked if they could identify the culprit from a group of pictures. Some of the participants -"Good, you identified the suspect"; others weren't. The feedback couldn't possibly influence the were then given feedback accuracy of the identification, because the feedback arrived only after the identification had occurred. But the feedback did have a large impact on how confident participants said they'd been when making their lineup selection (see Figure 8.6), and so, with confidence inflated but accuracy unchanged, the linkage between confidence and accuracy was essentially eliminated. (Wells & Bradfield, 1998; also see Douglas, Neuschatz, Imrich, & Wilkinson, 2010; Semmler & Brewer, 2006; Wells, Olson, & Charman, 2002, 2003; Wright & Skagerberg, 2007.) Similarly, think about what happens if someone is asked to report on an event over and over. The repetitions don't change the memory content-and so the accuracy of the report won't change much from one repetition to the next. However, with each repetition, the recall becomes easier and more fluent, and this ease of recall seems to make people more confident that their memory is correct. So here, too, accuracy is unchanged but confidence is inflated-and thus there's a gradual erosion, with each repetition, of the correspondence between accuracy and confidence. (For more disconnection between accuracy and confidence, see, e.g., Bradfield Douglas & Pavletic, 2012; Charman, Wells, & Joy, 2011.)
In many settings, therefore, we cannot count on confidence as a means of separating accurate memories from inaccurate ones. In addition, other findings tell us that memory errors can be just as emotional, just as vivid, as accurate memories (e.g., McNally et al., 2004). In fact, research overall suggests that there simply are no indicators that can reliably guide us in deciding which memories to trust and which ones not to trust. For now, it seems that memory errors, when they occur, may often be undetectable. e. Demonstration 8.2: Memory Accuracy and Confidence As you have seen, a large part of Chapter 8 is concerned with the errors people make when they're trying to recall the past. But how powerful are the errors? Here is one way to find out. In this demonstration, you will read a series of sentences. Be warned: The sentences are designed to be tricky and are similar to one another. Several of the sentences describe one scene; several describe other scenes. To make this challenging, though, the scenes are interwoven (and so you might get a sentence about Scene 1, then a sentence about Scene 2, then another about Scene 1, then one about Scene 3, and so on).
Try to remember the sentences-including their wording-as accurately as you can. Try this so that you can really focus on the sentences. Can you avoid demonstration in a quiet setting, making any mistakes?
To help you just a little, the memory test will come immediately after the sentences, so that there's no problem created by a long delay. To help you even more, the memory test will be a recoqnition test, so that the sentences will be supplied for you, with no demand that you come up with the sentences on your own. Finally, to allow you to do your best, the memory test won't force you into a yes-or-no format. Instead, it will allow you to express degrees of certainty. Specifically, in the memory test you'll judge, first, whether or not each test sentence was included in the original list. Second, you'll indicate how confident you are, using 0 % to indicate "I'm really just guessing" and 100% to indicate "I'm totally certain." Of course, you can use values between 0% and 100% to indicate intermediate levels of certainty.
In short, this is a demonstration designed to ask how good memory can be-with many factors in place to support performance: concrete, meaningful materials; ample warning about the nature of the materials; encouragement for you to give your best effort; immediate testing; recognition testing (not recall); and the option for you to "hedge your bets" by expressing your degree of certainty. Can we; in these ways, document nearly perfect memory?
Here are the sentences to memorize. Read them with care, because-as already mentioned- they are tricky to remember. HIDE
1. The girl broke the window on the porch.
2. The tree in the front yard shaded the man who was smoking his pipe.
3. The hill was steep.
4. The cat, running from the barking dog, jumped on the table.
5. The tree was tall.
6. The old car climbed the hill.
7. The cat running from the dog jumped on the table.
8. The girl who lives next door broke the window on the porch.
9. The car pulled the trailer.
10. The scared cat was running from the barking dog.
11. The girl lives next door.
12. The tree shaded the man who was smoking his pipe.
13. The scared cat jumped on the table.
14. The girl who lives next door broke the large window.
15. The man was smoking his pipe.
16. The old car climbed the steep hill.
17. The large window was on the porch.
18. The tall tree was in the front yard.
19. The car pulling the trailer climbed the steep hill.
20. The cat jumped on the table.
21. The tall tree in the front yard shaded the man.
22. The car pulling the trailer climbed the hill.
23. The dog was barking.
24. The window was large.
Now, close the list of sentences for the memory test.
Get a piece of paper and expand the list of sentences below. For each of the sentences, was the sentence on the previous list? If so, write "Old" Or is this a new sentence? If so, write "New." Also, for each one, mark how confident you are, with 0% meaning "just guessing" and 100% indicating "totally certain." Remember, you can also use values between 0% and 100% to indicate intermediate levels of certainty. SHOW Expand the first list of sentences. How well did you do? This is the moment at which we confess that there is a trick here: Every one of the test sentences was new. None of the test sentences were identical to the sentences used in the original presentation. For many of the test sentences, you probably (correctly) said "New" and were quite confident in your response. Which test sentences were these? Odds are good that you gave a high-confidence "New" response to a test sentence that mixed together elements from the different scenes. For example, you were probably confident and correct in rejecting "The old man who was smoking his pipe climbed the steep hill," because the man with the pipe came from one scene (he was by the tree) and the steep hill came from a different scene (with the car climbing the hill). For these sentences, you could rely on your memory for the overall gist of the memory materials, and memory for gist tends to be quite good. On this basis, you easily (and accurately) rejected sentences that didn't fit with that gist.
But for other test sentences, you probably said "Old" and may even have indicated 90% or 100% confidence that the sentences were familiar. But no matter how certain you were, you were wrong. nnot count on confidence as an indication of accurate memories. Let's be clear, therefore, that we Even high-confidence recollection can be wrong.
As a separate implication, notice how hard it is to remember a sentence's phrasing even in circumstances that are designed to help your memory. (Again, the testing was immediate. Recognition testing meant that you didn't have to come up with sentences on your own. You were warned that the test would be difficult. You were trying to do well, and you'd been told that you should try to remember the sentence's wording.) Even in this setting, errors (including high- confidence errors) can occur. Of course, one might argue that this is an acceptable pattern. After all, what you typically want to remember is the gist of a message, not the exact wording. Do you care whether you recall the exact phrasing of this paragraph? Or is it more important that you remember the point being made here? Nonetheless, there are situations in which you do want to remember the wording, and for that reason the results of this demonstration are troubling. There are also situations in which you might have misunderstood what you experienced, or your understanding might be incomplete. Those situations make it worrisome that what you remember seems to be dominated by your understanding, and not by the "raw materials" of your experience.
Demonstration adapted from Bransford, J. (1979). Human cognition: Learning, understanding and remembering, 1st ed. Belmont, CA: Wadsworth. 1979 Wadsworth, a part of Cengage Learning, Inc. Reproduced by permission (www.cengage.com/permissions). Forgetting We've been discussing the errors people sometimes make in recalling the past, but of course there's another way your memory can let you down: Sometimes you forget. You try to recall what was on the shopping list, or the name of an acquaintance, or what happened last week, and you simply draw a blank. Why does this happen? Are there things you can do to diminish forgetting? The Causes of Forgetting Let's start with one of the more prominent examples of "forgetting"-which turns out not to be forgetting at all. Imagine meeting someone at a party, being told his name, and moments later realizing you don't have a clue what his name is-even though you just heard it. This common (and experience is not the result of ultra-rapid forgetting. Instead, it stems from a failure in acquisition. You were exposed to the name but barely paid attention to it and, as a result, never embarrass learned it in the first place.
What about "real" cases of forgetting-cases in which you once knew the information but no longer do? For these cases, one of the best predictors of forgetting (not surprisingly) is the passage of time. Psychologists use the term retention interval to refer to the amount of time that elapses between the initial learning and the subsequent retrieval; as this interval grows, you're likely to forget more and more of the earlier event (see Figure 8.7). One explanation for pattern comes from the decay theory of forgetting, which proposes rather directly that memories fade or erode with the passage of time. Maybe this is because the relevant brain cells die off. Or maybe the connections among memories need to be constantly refreshed-and if they're not refreshed, the connections gradually weaken.
A different possibility is that new learning somehow interferes with older learning. This view is referred to as interference theory. According to this view, the passage of time isn't the direct cause of forgetting. Instead, the passage of time creates the opportunity for new learning, and it is the new learning that disrupts the older memories.
A third hypothesis blames retrieval failure. The idea here is that the "forgotten memory" is still in long-term storage, but the person trying to retrieve the memory simply cannot locate it. This proposal rests on the notion that retrieval from memory is far from guaranteed, and we argued in Chapter 7 that retrieval is more likely if your perspective at the time of retrieval matches the perspective in place at the time of learning. If we now assume that your perspective is likely to change as time goes by, we can make a prediction about forgetting: The greater the interval, the greater the likelihood that your perspective has changed, and therefore the greater the likelihood of retrieval failure. Which of these hypotheses is correct? It turns out that they all are. Memories do decay with the passage of time (e.g., Altmann & Schunn, 2012; Wixted, 2004; also Hardt, Nader, & Nadel, 2013; Sadeh, Ozubko, Winocur, & Moscovitch, 2016), so any theorizing about forgetting must include this factor. But there's also no question that a great deal of "forgetting" is retrieval failure. This point is evident whenever you're initially unable to remember some bit of information, but then, a while later, you do recall that information. Because the information was eventually retrieved, we know that it wasn't "erased" from memory through either decay or interference. Your initial failure to recall information, then, must be counted as an example of retrieval failure.
Sometimes retrieval failure is partial: You can recall some aspects of the desired content, but not all. An example comes from the maddening circumstance in which you're trying to think of a word but simply can't come up with it. The word is, people say, on the "tip of their tongue," and following this lead, psychologists refer to this as the TOT phenomenon. People experiencing this state can often recall the starting letter of the sought-after word and approximately what it sounds like. So, for example, "scrimshaw" or "something like secant" in trying to remember "sextant" (Brown, 1991; Brown & a person might remember "it's something like Sanskrit" in trying to remember McNeill, 1966; Harley & Brown, 1998; James & Burke, 2000; Schwartz & Metcalfe, 2011).
What about interference? In one early study, Baddeley and Hitch (1977) asked rugby players to recall the names of the other teams they had played against over the course of a season. The key here is that not all players made it to all games (because of illness, injuries, or schedule conflicts). This fact allows us to compare players for whom "two games back" means two weeks ago, to players for whom "two games back" means four weeks ago. In this way, we can look at the effects of retention interval (two weeks vs. four) with the number of intervening games held constant. Likewise, we can compare players for whom the game a month ago was "three games back" to players for whom a month ago means "one game back" Now, we have the retention interval held constant, and we can look at the effects of intervening events. In this setting, Baddeley and Hitch reported that the mere passage of time accounts for very little; what really matters is the number of intervening events (see Figure 8.8). This is just what we would expect if interference, and not decay is the major contributor to forgetting.
But why does memory interference occur? Why can't the newly acquired information coexist with older memories? The answer has several parts, but one element is linked to issues we've already discussed: In many cases, newly arriving information gets interwoven with older information, producing a risk of confusion about which bits are old (i.e., the event you're trying to remember) and which bits are new (i.e., information that you picked up after the event). In addition, in some cases, new information seems literally to replace old information-much as you no longer save the rough draft of one of your papers once the final draft is done. In this situation, the new information isn't woven into the older memory; instead, it erases it. Undoing Forgetting Is there any way to undo forgetting and to recover seemingly lost memories? One option, often discussed, is hypnosis. The idea is that under hypnosis a person can "return" to an earlier event and remember virtually everything about the event, including aspects the person didn't even notice (much less think about) at the time.
The reality, however, is otherwise. Hypnotized participants often do give detailed reports of the target event, but not because they remember more; instead, they're just willing to say more in order to comply with the hypnotist's instructions. As a result, their "memories" are a mix of recollection guesses, and inferences-and, of course, the hypnotized individual cannot tell which of these are which (Lynn, Neuschatz, Fite, &Rhue, 2001; Mazzoni & Lynn, 2007; Spiegel, 1995). On the positive side, though, there are procedures that do seem to diminish forgetting, including the so-called cognitive interview. This procedure was designed to help police in their investigations and, specifically, is aimed at maximizing the quantity and accuracy of information obtained from eyewitnesses to crimes (Fisher & Schreiber, 2007; Memon, Meissner, & Fraser, 2010). The cognitive interview has several elements, including an effort toward context reinstatement-steps that put witnesses back into the mindset they were in at the time of the crime. (For more on context Chapter 7.) In addition, the cognitive interview builds on the simple fact that reinstatement, see retrieval of memories from long-term storage is more likely if a suitable cue is provided. The interview therefore offers a diverse set of retrieval cues with the idea that the more cues provided, the greater the chance of finding one that triggers the target memory.
The cognitive interview is quite successful, both in the laboratory and in real crime investigations, producing more complete recollection without compromising accuracy. This success adds to the argument that much of what we call "forgetting" can be attributed to retrieval failure and can be undone simply by providing more support for retrieval.
Also, rather than undoing forgetting, perhaps we can avoid forgetting. The key here is simply to "revisit a memory periodically. Each "visit seems to refresh the memory, with the result that forgetting is much less likely. Researchers have examined this effect in several contexts, including one that's pragmatically quite important: Students often have to take exams, and confronting the material on an exam is, of course, an occasion in which students "revisit" what they've learned. These revisits, we've just suggested, should slow forgetting, and on this basis, taking an exam can actually help students to hang on to the material they've learned. Several studies have confirmed this "testing effect: Students have better long-term retention for materials they were tested on, compared materials they weren't tested on. (See, e.g., Carpenter, Pashler, & Cepeda, 2009; Halamish & Bjork, 2011; Healy, Jones, Lalchandani, & Tack, 2017; Karpicke, 2012; Karpicke & Blunt, 2011; McDaniel, Anderson, Derbish, & Morrisette, 2007; Pashler, Rohrer, Cepeda, & Carpenter, 2007; Rowland, 2014.)
We might mention that similar effects can be observed if students test themselves periodically, taking little quizzes that they've created on their own. Related effects emerge if students are occasionally asked questions that require a brief revisit to materials they've encountered (Brown. Roediger, & McDaniel, 2014). In fact, that's the reason why this textbook includes Test Yourself questions; those questions will actually help readers to remember what they've read! e. Demonstration 8.3: The Tip-of-the-Tongue Effect Your memory usually serves you well, quickly and easily providing all the information you need. But your memory can also let you down. Sometimes you'll fail to remember something because you paid insufficient attention to the information when you first met it. As a result, the information was never recorded in memory, and so of course you can't remember it later. In other settings, the information was recorded in memory but has now been lost-perhaps through decay, or perhaps through interference. In still other cases, the information was recorded in memory and remains there, but you can't find the information when you want it. This last pattern is what we call "retrieval failure"- an inability to locate information that is, in fact, still in storage.
Retrieval failure is our best explanation for cases in which you fail to remember something but later (when provided with a proper hint or suitable context) can recall the target information. The fact that your recall eventually succeeds tells us that the information was recorded and wasn't lost. The initial failure to remember, therefore, has to be understood as a problem in retrieval.
Retrieval failure is often complete: You utterly forget that you were supposed to stop at the bank on the way home (but then remember, when you later reach into your empty pocket). You completely forget about a concert you attended years ago (but then remember, when you hear one of the band's songs on Pandora or Spotify). Sometimes, however, retrieval failure is partial: You can recall part of the information you're after, but not all of it. Consider, for example, the common (but maddening) state in which you're trying to think of a word, but you just can't come up with it. You're sure you know the word, but, no matter how hard you try, you can't recall it, and so the word remains, people say, "on the tip of your tongue." In line with this expression, psychologists refer to this as the "TOT" effect. In this situation, you may eventually come up with the word-and so it plainly recall the word, therefore, is another instance of retrieval failure-an inability to locate information was in your memory. Your initial inability to in storage.
In case you've never experienced the frustration of the TOT state, consider the following definitions. In each case, is the related word or name in your vocabulary? If it is, can you think of the word? If the word is in your vocabulary but you can't think of it right now, can you recall what letter the word starts with? Can you remember how many syllables it has?
You may not know some of these terms at all; other terms will immediately spring to mind. But in at least some cases, you're likely to end up in the frustrating state of having the word at the tip of your tongue but not being able to think of it.
1. The aromatic substance found in the gut of some whales, valued in earlier years for the manufacture of perfumes. 2. A tube-shaped instrument that is rotated to produce complex, symmetrical designs, created by light shining through mirrors inside the instrument
A structure of open latticework, usually made of wood, used as a support for vines or other 3. climbing plants .
4. The legendary Roman slave who was spared in the arena when the lion recognized him as the man who had removed a thorn from its paw.
5. An infectious, often fatal disease, often transmitted through contaminated animal substances and sometimes transmitted, in powder form, as an agent in germ warfare
6. The scholarly study of word origins and word histories
7. The American magician who died in 1926, famous for his escapes from chains, handcuffs, straitjackets, and padlocked boxes
8. People who explore caves as a hobby or sport
9. An instance of making a discovery by lucky accident
10. An instrument for measuring wind velocity
11. An Asian art form involving complex paper folding
12. The formal term for the collection and study of postage stamps and related material
13. A word or phrase that reads the same way backward or forward (e.g., "Madam I'm Adam")
14. A building, usually stone, housing a large tomb or several tombs
15. The verb meaning to give up the throne
16. The sense of resentment often felt in response to an imagined insult
17. The term for the three dots used to indicate a pause or an omission (...) 18. The length of leather used in older times for sharpening razor
19. The accumulation of stones carried along, and eventually dropped, by a glacier
20. Someone who makes maps
21. Lasting only a very brief time
Open the following bar to find out what the words are. SHOW Demonstration adapted from Brown, R., & McNeill, D. (1966). The "tip of the tongue" phenomenon. Journal of Verbal Learning and Verbal Behavior, 5, 325-337. See also James, L., & Burke, D. (2000). Phonological priming effects on word retrieval and tip-of-the-tongue experiences in young and older adults. Journal of Experimental Psychology: Learning, Memory and Cognition, 26, 1378-1391. Memory: An Overall Assessment We've now seen that people sometimes recall with confidence events that never took place, and sometimes forget information they'd hoped to remember. But we've also mentioned the positive side of things: how much people can recall, and the key fact that your memory is accurate far more often than not. Most of the time, it seems, you do recall the past as it truly was.
Perhaps most important, we've also suggested that memory's "failings" may simply be the price you pay in order to gain crucial advantages. For example, we've argued that memory errors arise because the various episodes in your memory are densely interconnected with one another; it's these interconnections that allow elements to be transplanted from one remembered episode to another. But we've also noted that these connections have a purpose: They're the retrieval paths that make memory search possible. Therefore, to avoid the errors, you would need to restrict the connections; but if you did that, you would lose the ability to locate your own memories within long- term storage. memory connections that lead to error also help you in other ways. Our environment, after all, is in many ways predictable, and it's enormously useful for you to There's little point, for example, in scrutinizing a kitchen to make sure there's a stove in the room, exploit that predictability because in the vast majority of cases there is. So why take the time to confirm the obvious? Likewise, there's little point in taking special note that, yes, this restaurant does have menus and, yes, people in the restaurant are eating and not having their cars repaired. These, too, are obvious points, and it would be a waste of effort to give them special notice.
On these grounds, reliance on schematic knowledge is a good thing. Schemata guide your attention to what's informative in a situation, rather than what's self-evident (e.g., Gordon, 2006), and they guide your inferences at the time of recall. If this use of schemata sometimes leads you astray, that's a small price to pay for the gain in efficiency that schemata allow. (For similar points see Chapter 4.)
In the same way, the blurring together of episodes may be a blessing, not a problem. Think, for example, about all the times when you've been with a particular friend. These episodes are related to one another in an obvious way, and so they're likely to become interconnected in your memory. This will cause difficulties if you want to remember which episode is which and whether you had a particular conversation in this episode or in that one. But rather than lamenting this, maybe we should celebrate what's going on here. Because of the "interference," all the episodes will merge together in your memory, so that what resides in memory is one integrated package, containing all of your knowledge about your friend. As a result, rather than complaining about memory confusion we should rejoice over the memory integration and "cross-referencing." In all of these ways, then, our overall assessment of memory can be rather upbeat. We have, to be sure, discussed a range of memory errors, but these errors are in most cases a side product of mechanisms that otherwise help you-to locate your memories within storage, to be efficient in your contact with the world, and to form general knowledge. Thus, even with the errors, even with forgetting, it seems that human memory functions in a way that serves us extraordinarily well. (For more on the benefits produced by memory's apparent limitations, see Howe, 2011; Nørby, 2015; Schacter, Guerin, & St. Jacques, 2011.) Autobiographical Memory Most of the evidence in Chapters 6 and 7 was concerned with memory for simple stimuli-such as word lists or short sentences. In this chapter, we've considered memories for more complex materials, and this has drawn our attention to the ways in which your knowledge (whether knowledge of a general sort or knowledge about related episodes) can both improve memory and also interfere with it.
In making these points, we've considered memories in which the research participant was actually involved in the remembered episode, and not just an external witness (e.g., the false memory that he committed a felony). We've also looked at studies that involved memories for emotional events (e.g., the plane crash discussed at the chapter's start) and memory over the very long term (e.g., memories for childhood events "planted" in adult participants).
Do these three factors-involvement in the remembered event, emotion, and long delay-affect how or how well someone remembers? These factors are surely relevant to the sorts of remembering people do outside the laboratory, and all three are central for autobiographical memory. This is the memory that each of us has for the episodes and events of our lives, and this sort of memory plays a central role in shaping how each of us thinks about ourselves and, therefore how we behave. (For more on the importance of autobiographical memory, see Baddeley, Aggleton, & Conway, 2002; Prebble, Addis, & Tippett, 2013; Steiner, Thomsen, & Pillemer, 2017. For more on the distinction between the types of memory, including biological differences between autobiographical memory and "lab memory," see Cabeza & St. Jacques, 2007; Hodges & Graham, 2001; Kopelman & Kapur, 2001; Tulving, 1993, 2002.) Let's explore how the three factors we've mentioned, each seemingly central for autobiographical memory, influence what we remember. Memory and the Self Having some involvement in an event (as opposed to passively witnessing it) turns out to have a large effect on memory, because, overall, information relevant to the self is better remembered than information that's not self-relevant-a pattern known as the "self-reference effect" (e.g., Symons & Johnson, 1997; Westmacott & Moscovitch, 2003). This effect emerges in many forms, including an advantage in remembering adjectives that apply to you relative to adjectives that don't, better memory for names of places you have visited relative to names of places you've never been, and so on (see Figure 8.9). But here, too, we can find memory errors, in part because your "memory" for your own life is (just like other memories) a mix of genuine recall and some amount of schema-based reconstruction. For example, consider the fact that most adults believe they've been reasonably consistent, reasonably stable, over their lifetimes. They believe, in other words, that they've always been pretty much the same as they are now. This idea of consistency is part of their self-schema -the set of interwoven beliefs and memories that constitute people's knowledge about themselves. When the time comes to remember the past, therefore, people will rely to some extent on this belief in their own consistency, so they'll reconstruct their history in a biased way-one that maximizes the (apparent) stability of their lives. As a result, people often misremember their past attitudes and past romantic relationships, unwittingly distorting their personal history in a way that makes the past look more like the present than it really was. (See Conway & Ross, 1984; Holmberg & Homes, 1994. For related results, see Levine, 1997; Marcus, 1986; McFarland & Buehler, 2012; Ochsner & Schacter 2000; Ross & Wilson, 2003.) It's also true that most of us would like to have a positive view of ourselves, including a positive view of how we've acted in the past. This, too, can shape memory. As one illustration, Bahrick, Hall,and Berger (1996) asked college students to recall their high school grades as accurately as they could, and the data showeda clear pattern of self-service. When students forgot a good grade, their (self-serving) reconstruction led them to the (correct) belief that the grade must have been a good one; consistent with this, 89 % of the A's were correctly remembered. But when students forgot a poor grade, reconstruction led them to the (false) belief that the grade must have been okay; as a result, only 29% of the D's were correctly recalled. (For other mechanisms through which motivation can color autobiographical recall, see Conway & Holmes, 2004; Conway & Pleydell-Pearce, 2000; memory. As one illustration, Bahrick, Hall, Molden & Higgins, 2012.) Memory and Emotion Another factor important for autobiographical memory is emotion. Many of your life experiences are of course emotional, making you feel happy, or sad, or angry, or afraid, and in general emotion helps you to remember. One reason is emotion's impact on memory consolidation-the process through which memories are biologically "cemented in place." (See Hardt, Einarsson, & Nader, 2010; Wang & Morris, 2010; although also see Dewar, Cowan, & Della Sala, 2010.)
Whenever you experience an event or gain new knowledge, your memory for this new content is initially fragile and is likely represented in the brain via a pattern of neural activation. Over the next few hours, though, various biological processes stabilize this memory and put it into a more enduring form. This process-consolidation-takes place "behind the scenes," without you thinking about it, but it's crucial. If the consolidation is interrupted for some reason (e.g., because of extreme fatigue or injury), no memory is established and recall later will be impossible. (That's because there's no information in memory for you to retrieve; you can't read text off a blank page!)
A number of factors can promote consolidation. For example, evidence is increasing that key steps of consolidation take place while you're asleep-and so a good night's rest actually helps you, later on, to remember things you learned while awake the day before. (See Ackermann & Rasch. 2014: Giuditta, 2014; Rasch & Born, 2013; Tononi & Cirelli, 2013; Zillmer, Spiers, & Culbertson, 2008.) Also, there's no question that emotion enhances consolidation. Specifically, emotional events trigger a response in the amygdala, and the amygdala in turn increases activity in the hippocampus. The hippocampus is, as we've seen, crucial for getting memories established. (See Chapter 7; for reviews of emotion's biological effects on memory, see Buchanan, 2007; Hoschedidt, Dongaonkar, Payne, & Nadel, 2010; Joels, Fernandez, & Roosendaal, 2011; Kensinger, 2007; LaBar, 2007; LaBar & Cabeza, 2006; Yonelinas & Ritchey, 2015. For a complication, though, see Figure 8.10.) Emotion also shapes memory through other mechanisms. An event that's emotional is likely to be important to you, virtually guaranteeing that you'll pay close attention as the event unfolds, and we know that attention and thoughtful processing help memory. Moreover, you tend to mull over emotional events in the minutes (or hours) following the event, and this is tantamount to memory rehearsal. For all these reasons, it's not surprising that emotional events are well remembered (Reisberg & Heuer, 2004; Talmi, 2013).
Let's note, though, that emotion doesn't just influence how well you remember; it also influences what you remember. Specifically, in many settings, emotion seems to produce a "narrowing" of attention, so that all of your attention will be focused on just a few aspects of the scene (Easterbrook, 1959). This narrowing helps guarantee that these attended aspects will be firmly placed into memory, but it also implies that the rest of the event, excluded from the narrowed focus, won't be remembered later (e.g., Gable & Harmon-Jones, 2008; Reisberg & Heuer, 2004; Steblay, 1992).
What exactly you'll focus on, though, may depend on the specific emotion. Different emotions lead you to set different goals: If you're afraid, your goal is to escape; if you're angry, your goal is to deal with the person or issue that's made you angry; if you're happy, your goal may be to relax and enjoy! In each case, you're more likely to pay attention to aspects of the scene directly relevant to your goal, and this will color how you remember the emotional event. (See Fredricks on, 2000; Harmon-Jones, Gable, & Price, 2013; Huntsinger, 2012, 2013; Kaplan, Van Damme, & Levine, 2012 Levine & Edelstein, 2009.) Flashbulb Memories
One group of emotional memories seems special. These are the so-called flashbulb memories memories of extraordinary clarity, typically for highly emotional events, retained despite the passage of many years. When Brown and Kulik (1977) introduced the term "flashbulb memory," they pointed to the memories people had of the moment in 1963 when they first heard that President Kennedy had been assassinated. In the Brown and Kulik study, people interviewed more than a decade after that event remembered it "as though it were yesterday," and many participants were certain they'd never forget that awful day. Moreover, participants' recollection was quite detailed-with people remembering where they were at the time, what they were doing, and whom they were with. Indeed many participants were able to recall the clothing worn by people around them, the exact words uttered, and the like.
Many other events have also produced flashbulb memories. clearly recall where they were when they heard about the attack on the World Trade Center in 2001; or example, most Americans can many people vividly remember what they were doing in 2009 when they heard that Michael Jackson had died; many Italians have clear memories of their country's victory in the 2006 World Cup; and so on. (See Pillemer, 1984; Rubin & Kozin, 1984; also see Weaver, 1993; Winograd & Neisser, 1993.)
Remarkably, though, these vivid, high-confidence memories can contain substantial errors. Thus, when people say, "Ill never forget that day. . " they're sometimes wrong. For example, Hirst et al. (2009) interviewed more than 3,000 people soon after the September 11 attack on the World Trade Center, asking how they first heard about the attack; who brought them the news; and what they were doing at the time. When these individuals were re-interviewed a year later, however, more than a third (37%) provided a substantially different account. Even so, the participants were strongly confident in their recollection (rating their degree of certainty, on a 1-to-5 scale, at an average of 4.4). The outcome was the same for participants interviewed three years after the attack-with 43% offering different accounts from those they had given initially. (For similar data, see Neisser & Harsch, 1992; also Hirst & Phelps, 2016; Rubin & Talarico, 2007; Schmidt, 2012; Talarico & Rubin, 2003.)
Other data, though, tell a different story, suggesting that some flashbulb memories are entirely accurate. Why should this be? Why are some flashbulb events remembered well, while others aren't? The answer involves several factors, including how, how often, and with whom someone discusses the flashbulb event. In many cases, this discussion may encourage people to "polish" their reports- so that they're offering their audience a "better," more interesting narrative. After a few occasions of telling and re-telling this version of the event, the new version may replace the original memory. (For more on these issues, see Conway et al., 1994; Hirst et al., 2009; Luminet & Curci, 2009; Neisser, Winograd, & Weldon, 1991; Palmer, Schreiber, & Fox, 1991; Tinti, Schmidt, Sotgiu, Testa, & Curci, 2009: Tinti, Schmidt, Testa, & Levine, 2014.)
Notice, then, that an understanding of flashbulb memories requires us to pay attention to the social aspects of remembering. In many cases, people "share" memories with one another (and so, for example, I tell you about my vacation, and you tell me about yours). Likewise, in the aftermath of an important event, people often compare their recollections. ("Did you see how he ran when the alarm sounded!?") In all cases, people are likely to alter their accounts in various ways, to allow for a better conversation. They may, for example, leave out mundane bits, or add bits to make their account more interesting or to impress their listeners. These new points about how the event is described will, in turn, often alter the way the event is later remembered.
In addition, people sometimes "pick up" new information in these conversations-if, for example, someone who was present for the same event noticed a detail that you missed. Often, this new information will be absorbed into other witnesses' memory-a pattern sometimes referred to as "co- witness contamination." Let's note, though, that sometimes another person who witnessed the event will make a mistake in recalling what happened, and, after conversation, other witnesses may absorb this mistaken bit into their own recollection (Hope, Gabbert, & Fraser, 2013). In this way, conversations after an event can sometimes have a positive impact on the accuracy and content of a person's eventual report, and sometimes a negative impact.
For all these reasons, then, it seems that "remembering" is not an activity shaped only by the person who holds the memory, and exploring this point will be an important focus for future research. (For early discussion of this broad issue, see Bartlett, 1932. For more recent discussion, see Choi, Kensinger, & Rajaram, 2017; Gabbert & Hope, 2013; Roediger & Abel, 2015.) Returning to flashbulb memories, though, let's not lose track of the fact that the accuracy of these memories is uneven. Some flashbulb memories are marvelously accurate; others are filled with error. Therefore, the commonsense idea that these memories are somehow "burned into the brain," and thus always reliable, is surely mistaken. In addition, let's emphasize that from the point of view of the person who has a flashbulb memory, there's no detectable difference between an accurate flashbulb memory and an inaccurate one: Either one will be recalled with great detail and enormous confidence. In each case, the memory can be intensely emotional. Apparently, memory errors can occur even in the midst of our strongest, most vivid recollections.
Flashbulb memories usually concern events that were strongly emotional. Sadly, though, we can also find cases in which people experience truly extreme emotion, and this leads us to ask: How are traumatic events remembered? If someone has witnessed wartime atrocities, can we count on the accuracy of their testimony in a war-crimes trial? If someone suffers through the horrors of a sexual assault, will the painful memory eventually fade?
Evidence suggests that most traumatic events are well remembered for many years. In fact, victims of atrocities often seem plagued by a cruel enhancement of memory, leaving them with extra-vivid and long-lived recollections of the terrible event (e.g., Alexander et al., 2005; Goodman et al., 2003: Peace & Porter, 2004; Porter & Peace, 2007; Thomsen & Berntsen, 2009). As a result, people who have experienced trauma sometimes complain about having "too much" memory and wish they remembered less. This enhanced memory can be understood in terms of a mechanism we've already discussed: consolidation. This process is promoted by the conditions that accompany bodily arousal, including the extreme arousal typically present in a traumatic event (Buchanan & Adolphs, 2004; Hamann, 2001; McGaugh, 2015). But this doesn't mean that traumatic events are always well remembered. There are, in fact, cases in which people who've suffered through extreme events have little or no recall of their experience (e.g., Arrigo & Pezdek, 1997). We can also sometimes document substantial errors in someone's recall of a traumatic event (Paz-Alonso & Goodman, 2008).
What factors are producing this mixed pattern? In some cases, traumatic events are accompanied by sleep deprivation, head injuries, or substance abuse, each of which can disrupt memory (McNally, 2003). In other cases, the memory-promoting effects of arousal are offset by the complex memory effects of stress. The key here is that the experience of stress sets off a cascade of biological reactions. These reactions produce changes throughout the body, and the changes are generally beneficial, helping the organism to survive the stressful event. However, the stress-produced changes are disruptive to some biological functions, and this can lead to a variety of problems (including medical problems caused by stress). How does the mix of stress reactions influence memory? The answer is complicated. Stress experienced at the time of an event seems to enhance memory for materials directly relevant to the Source of the stress, but has the opposite effect-undermining memory-for other aspects of the event (Shields, Sazma, McCullough, & Yonelinas, 2017). Also, stress experienced during memory retrieval interferes with memory, especially if the target information was itself emotionally charged.
How does all this play out in situations away from the laboratory? One line of evidence comes from a study of soldiers who were undergoing survival training. As part of their training, the soldiers through a highly realistic simulation of a prisoner- of-war interrogation. One day later, the soldiers were asked to identify the interrogator from a lineup. Despite the extensive (40-minute) face-to-face encounter with the interrogator and the relatively short (one-day) retention interval, many soldiers picked the wrong person from the lineup. Soldiers who had experienced a moderate-stress interrogation picked the wrong person from a live lineup 38% of the time; soldiers who had experienced a high-stress interrogation (one that included a physical confrontation) picked the wrong person 56 % of the time if tested with a live lineup, and et al., 2004; also see Deffenbacher, Bornstein, Penrod, & McCorty, 2004; Hope, Lewinski, Dixon, Blocksidge, & Gabbert, 2012; Valentine & were deprived of sleep and food, and they went 68% of the time if tested with a photographic lineup. (See Morgan Messout, 2008.) Repression and "Recovered" Memories Some authors argue in addition that people defend themselves against extremely painful memories by pushing these memories out of awareness. Some writers suggest that the painful memories are "repressed"; others use the term "dissociation" to describe this self-protective mechanism. No matter what terms we use, the idea is that these painful memories (including, in many cases, memories for childhood abuse) won't be consciously available but will still exist in a person's long- term storage and in suitable circumstances can be "recovered"-that is, made conscious again. (See for discussion, Belli, 2012; Freyd, 1996, 1998; Terr, 1991, 1994.)
Most memory researchers, however, are skeptical about this proposal. As one consideration, painful events-including events that seem likely candidates for repression-seem typically to be well remembered, and this is the opposite of what we would expect if a self-protective mechanism was in place. In addition, some of the abuse memories reported as "recovered" may, in fact, have been remembered all along, and so they provide no evidence of repression or dissociation. In these cases, the memories had appeared to be "lost" because the person refused to discuss these memories for many years; "recovery" of these memories simply reflects the fact that the person is at last willing to talk about them. This sort of "recovery" can be extremely consequential- emotionally and legally-but doesn't tell us anything about how memory works. Sometimes, though, memories do seem to be genuinely lost for a while and then recovered. But this pattern may not reveal the operation (and, eventually, the "lifting") of repression or dissociation. Instead, this pattern may be the result of retrieval failure-a mechanism that can "hide" memories for periods of time, only to have them reemerge once a suitable retrieval cue is available. Here, too, the recovery may be of enormous importance for the person who is finally remembering the long-lost episodes; but again, this merely confirms the role of an already-documented memory mechanism, with no need for theorizing about repression.
In addition, we need to acknowledge the possibility that at least some recovered memories may, in fact, be false memories. After all, we know that false memories occur and that they're more likely when someone is recalling the distant past than when one is trying to remember recent events. It's also relevant that many recovered memories emerge only with the assistance of a therapist who is genuinely convinced that a client's psychological problems stem from long-forgotten episodes of childhood abuse. Even if therapists scrupulously avoid leading questions, their expectations might still lead them to shape their clients' memory in other ways-for example, by giving signs of interest or concern if the clients hit on the "right" line of exploration, by spending more time on topics related to the alleged memories, and so on. In these ways, the climate within a therapeutic session could guide the client toward finding exactly the "memories" the therapist expects to find. Overall, then, the idea of a self-protective mechanism "hiding" painful memories from view is highly controversial. Some psychologists (often, those working in a mental health specialty) insist that they routinely observe this sort of self-protection, and other psychologists (generally, memory researchers) reject the idea that memories can be hidden in this way. It does seem clear, however, that at least some of these now-voiced memories are accurate and provide evidence for terrible crimes. As in all cases, though, the veracity of recollection cannot be taken for granted. This warning is important in evaluating any memory, but especially recollection. (For discussions of this difficult-and sometimes angrily debated-issue, see, among so for anyone wrestling with traumatic others, Belli, 2012; Brewin &Andrews, 2014, 2016; Dalenberg et al., 2012; Geraerts et al., 2009; Giesbrecht, Lynn, Lilienfeld, & Merckelbach, 2008; Kihlstrom, 2006; Küpper, Benoid, Dalgleish, & Anderson, 2014; Loftus, 2017; Ost, 2013; Patihis, Lilienfeld, Ho, & Loftus, 2014; Pezdek & Blandon- Gitlin, 2017.) Long, Long-Term Remembering
In the laboratory, a researcher might ask you to recall a word list you read just minutes ago or a film you saw a week ago. Away from the lab, however, people routinely try to remember events from years-perhaps decades-back. We've mentioned that these longer retention intervals are generally associated with a greater amount of forgetting. But, impressively, memories from long ago can sometimes turn out to be entirely accurate.
In an early study, Bahrick, Bahrick, and Wittlinger (1975; also Bahrick, 1984; Bahrick & Hall, 1991) tracked down the graduates of a particular high sch0ol-people who had graduated in the previous year, and the year before, and the year before that, and ultimately, people who had graduated 50 years earlier. These alumni were shown photographs from their own year's high school yearbook, and for each photo they were given a group of names and had to choose the name of the person shown in the picture. The data for this "name-matching" task show remarkably little forgetting approximately 90 % correct if tested 3 months after graduation, the same after 7 performance was years, and the same after 14 years. In some versions of the test, performance was still excellent after 34 years (see Figure 8.11). As a different example, what about the material you're learning right now? Five years from now will you still remember what you've learned? How about a decade from now? Conway, Cohen, and Stanhope (1991, 1992) explored these questions, testing students' retention of a cognitive psychology course taken years earlier. The results echo the pattern we've already seen. Some forgetting of names and specific concepts was observed during the first 3 years after the course. After the third year, however, performance stabilized, so that students tested after 10 years still remembered a fair amount-in fact, just as much as students tested after 3 years (see Figure 8.12). In an earlier section, we argued that the retention interval is crucial for memory and that memory gets worse as times goes by. The data now in front of us, though, indicate that how much the interval matters-that is, how quickly memories "fade"-may depend on how well established the memories were in the first place. The high school students in the Bahrick et al. study had seen their classmates day after day, for (perhaps) several years. They therefore knew their classmates' names very, very well-and this is why the passage of time had only a slight impact on their memories for the names. Likewise, students in the Conway et al. study had apparently learned their psychology quite well-and so they retained what they'd learned for a very long time. In fact, we first met this study in Chapter 6, when we mentioned that students' grades in the course were good predictors of how much the students would still remember many years after the course was done. Here, too, the better the original learning, the slower the forgetting.
We can maintain our claim, therefore, that the passage of time is the enemy of memory: Longer retention intervals produce lower levels of recall. However, if the material is very well learned at the start, and also if you periodically "revisit" the material, you can dramatically diminish the impact of the passing years. e. Demonstration 8.4: Memory for Words This demonstration begins with a memory test. You're going to read a list of words, then test your memory for what you just read.
Read through the following list at a comfortable pace. Then, close the list, and without looking at it, take a blank piece of paper and write down as many words from the list as you can. HIDE Shy Paris Blonde
Texas Athletic Dramatic
Tall Clever Nevada
Helpful Perth Black
Indiana Balding Sensitive
Flabby Generous Wisconsin
Calm Italy Muscular
England Slender Talented
Strong Creative Melbourne
Modest Peru Smart
Vancouver Pretty Cheerful
Clumsy Daring Vermont
Stylish Montreal Pierced
How many words did you recall? Now, go back to the original list, and put a star next to the words that in some way are related to you-words that describe you, that clearly describe the opposite of who you are, or that name a place that you care about (perhaps because you've been there, or because you've always wanted to go there). How many of these self-referential words (now starred) are there? How many of them did you remember? How many words on the list aren't starred (i.e., aren't self-referential)? How many of them did you remember?
The best way to evaluate these numbers is to compare your results to those of others. Trade your results with a classmate. How many of the self-referential words did you remember in comparison to d by people for whom the words weren't self- how many of those same words were remer referential?
Even without that comparison, though, did you have a memory advantage for the self-referential words? Most people do, and this pattern is known as the "self-reference effect." Notice, by the way, that we didn't mention this effect at the start of this demonstration. That's because we didn't want to draw your attention to words that referred to you. If we had, then this "extra" attention itself would have influenced your memory. How General Are the Principles of Memory? There is certainly more to be said about autobiographical memory. For example, it can't be surprising that people tend to remember significant turning points in their lives and often use these turning points as a means of organizing their autobiographical recall (Enz & Talarico, 2015; Rubin & Umanath, 2015). Perhaps related, there are also memory patterns associated with someone's age. Specifically, most people recall very little from the early years of childhood (before age 3 or so; e.g., Akers et al., 2014; Bauer, 2007; Hayne, 2004; Howe, Courage, & Rooksby, 2009; Morrison & Conway, 2010). In contrast, people generally have clear and detailed memories of their late adolescence and early adulthood, a pattern known as the "reminiscence bump." (See Figure 8.13; Conway & Haque, 1999; Conway, Wang, Hanyu, & Haque 2005; Dickson, Pillemer, & Bruehl, 2011; Koppel & Rubin, 2016; Rathbone, Moulin, & Conway, 2008; Rathbone, O'Connor, & Moulin, 2017.) As a result, for many Americans, the last years of high school and the years they spend in college are likely to be the most memorable periods of their lives. But in terms of the broader themes of this chapter, where does our brief survey of autobiographical memory leave us? In many ways, this form of memory is similar to other sorts of remembering. Autobiographical memories can last for years and years, but so can memories that don't refer directly to your own life. Autobiographical remembering is far more likely if the person occasionally revisits the target memories; these rehearsals dramatically reduce forgetting. But the same is true in non-autobiographical remembering.
Autobiographical memory is also open to error, just as other forms of remembering are. We saw this in cases of flashbulb memories that turn out to be false. We've also seen that misinformation and leading questions can plant false autobiographical memories-about birthday parties that never happened and trips to the hospital that never took place (also see Brown & Marsh, 2008). Misinformation can even reshape memories for traumatic events, just as it can alter memories for trivial episodes in the laboratory (Morgan, Southwick, Steffan, Hazlett, & Loftus, 2013; Paz-Alonso & Goodman, 2008).
These facts strengthen chapters: Certain principles seem to apply to memory in general, no matter what is being remembered. All memories depend on connections. The connections promote retrieval. The claim that has been emerging in our iscussion over the last three connections also facilitate interference, because they allow one memory to blur into another. The connections can fade with the passage of time, producing memory gaps, and the gaps are likely to be filled via reconstruction based on generic knowledge. All these things seem to be true whether we're talking about relatively recent memories or memories from long ago, emotional memories or memories of calm events, memories for complex episodes or memories for simple word lists. But this doesn't mean that all principles of memory apply to all types of remembering. As we saw in Chapter 7, the rules that govern implicit memory may be different from those that govern explicit memory. And as we've now seen, some of the factors that play a large role in shaping autobiographical remembering (e.g., the role of emotion) may be irrelevant to other sorts of memory.
In the end, therefore, our overall theory of memory is going to need more than one level of description. We'll need some principles that apply to only certain types of memory (e.g., principles specifically aimed at emotional remembering). But we'll also need broader principles, reflecting the fact that some themes apply to memory of all sorts (e.g., the importance of memory connections). As the last three chapters have shown, these more general principles have moved us forward considerably in our understanding of memory in many different domains and have enabled us to illuminate many aspects of learning, of memory retrieval, and of the sources of memory error. e. Demonstration 8.5: Childhood Amnesia Each of us remembers many things about our lives, so that, overall, our memories are rich and detailed. There is, however, one well-documented limit on the memories we have: Think back to to think about what something that happened when you were 10 years old. (It will probably help grade you were in and who your teacher was. Can you remember anything about that year?) How about when you were 9 years old? When you were 8? When you were 7? What is the earliest event in your life that you can remember?
Many people have trouble remembering events that took place before they were 4 years old. Very few people can remember events that took place before they were 3. This pattern is so common that it often gets a name-childhood amnesia, or sometimes infantile amnesia. Do you fit this pattern? Can you remember any events from the first three years of your life? If you can, is it possible that you're not remembering the event itself, but instead remembering family discussions about the event? Or remembering some photograph of the event? Several explanations have been offered for childhood amnesia, and probably each of them captures part of the truth. One important consideration, though, hinges on the young child's understanding of the world. As the textbook chapter discusses, we associating them with other knowledge that we have. But, of course, this requires that you have that typically remember events by other knowledge, so that you can link the new information to it. Young children lack this other knowledge-they lack a scaffold to which they can attach new information, and this makes it difficult for them to establish new information in memory.
As a further exploration, ask some of your friends about the earliest events in their lives that they men, can remember. Several lines of evidence suggest that women can recall earlier life events than and that children who were quite verbal at an early age can recall earlier life events than children who were less verbal. Do these claims fit with your observations? COGNITIVE PSYCHOLOGY AND EDUCATION remembering for the long term Sometimes you need to recall things after a short delay-a friend tells you her address and you drive to her apartment an hour later, or you study for a quiz that you'll take tomorrow morning. Sometimes, however, you want to remember things overa much longer time span-perhaps trying to recall things you learned months or years ago. This longer-term retention is certainly important in educational settings. Facts that you learn in high school may be crucial for your professional work later in life. Likewise, facts that you learn in your first year at college, or in your first year in a job, may be crucial in your third or fourth year. How, therefore, can we help people to remember things for the very long term?
The chapter has suggested a two-part answer to this question. First, you're more likely to hang on to material that you learned very well in the first place. The chapter mentions one study in which people tried to recall the material they'd learned in a college course a decade earlier. In that study students' grades in the course were good predictors of how much the students would remember years after the course was done-and so, apparently, the better the original learning, the slower the forgetting. long-term retention also depends on another factor-whether you occasionally "revisit" the material you've learned. Even a brief refresher can help enormously. In one study, students were quizzed on little factoids they had most likely learned at some prior point in their lives (Berger, Hall, & Bahrick, 1999)-for example, "Who was the first astronaut to walk on the moon?"; "Who wrote the fable about the fox and the grapes?" In many cases, the students knew these little facts but couldn't recall them at that moment. In that situation, the students were given a quick reminder. The correct answer was shown to them for 5 seconds, with the simple instruction that they should look at the answer because they would need it later on.
Nine days after this reminder, participants were able to recall roughly half the answers. This obviously wasn't perfect performance, but it was an enormous return (an improvement from 0 % to 50%) from a very small investment (5 seconds of "study time"). And it's likely that a second reminder a few days later, again lasting just 5 seconds, would have lifted their performance still further and allowed the participants to recall the items after an even longer delay.
One suggestion, then, is that testing yourself (perhaps with flashcards-with a cue on one side and an answer on the other) can be quite useful. Flashcards are often a poor way to learn material, because (as we've seen) learning requires thoughtful and meaningful engagement with the materials you're trying to memorize, and running through stack of flash cards probably won't promote that thoughtful engagement. But using flashcards may be an excellent way to review material that is already learned- and so a way to avoid forgetting this material. Other, more substantial, forms of testing can also be valuable. Think about what happens each time you take a vocabulary quiz in your Spanish class. A question like "What's the Spanish word for 'bed'?" gives you practice in retrieving the word, and that practice promotes fluency in retrieval. In addition, seeing the word (cama) can itself refresh the memory, promoting retention.
The key idea here is the "testing effect." This term refers to a consistent pattern in which students who have taken a test have better retention later on, in comparison to students who didn't take the initial test. (See, e.g., Carpenter, Pashler, & Cepeda, 2009; Glass & Sinha, 2013; Halamish & Bjork, 2011; Karpicke, 2012; McDermott, Agarwal, D'Antonio, Roediger, & McDaniel, 2014; Pyc & Rawson, 2012.) This pattern has been documented with students of various ages (including high school and college students) and with different sorts of material.
The implications for students should be clear. It really does pay to go back periodically and ademic year as wel review what you've learned-including materia you learned earlier this as material from previous years. The review doesn't have to be lengthy or intense; in the first study described here, just a 5-second exposure was enough to decrease forgetting dramatically.
Finally, you shouldn't complain if a teacher insists on giving frequent quizzes. Of course, quizzes can be a nuisance, but they serve two functions. First, they can help you assess your learning, so that you can judge whether-perhaps-you need to adjust your study strategies. Second, the quizzes actually help you retain what you've learned-for days, and probably months, and perhaps even decades after you've learned it. COGNITIVE PSYCHOLOGY AND THE LAW jurors' memory Throughout the textbook, we've covered many topics relevant to the question of what eyewitnesses to crimes-or crime victims-can or cannot remember. But memory is also relevant to the courts for another reason: Members of a jury sit and listen to hours (and, sometimes, many days) of courtroom testimony. Then, they move into the jury room, where, on the basis of their recollection of the testimony, they must evaluate the facts of the case and reach a verdict. But what if the jurors don't remember the testimony they've heard? In some courtrooms, members of the jury are allowed to take notes during the trial, but in many jurisdictions they aren't. Perhaps we should worry, therefore, about jurors' memories just as much as we worry about witnesses' memories.
Jurors' memories are influenced by the same factors as any other memories. For example, we know in general that people try to fit complex events into a mental framework, or schema. Aspects of the event that fit well with this framework are likely to be remembered. Aspects that don't fit with the framework may be forgotten or remembered in a distorted form, so that the recollection, now with its distorted content, does fit with the framework. This pattern has been documented in many settings, so it's not surprising that it can also be demonstrated in jurors. To see how this plays out, bear in mind that in the opening phase of a trial, lawyers from each side have a chance to address the jury, and they use this opportunity to describe the case to come, foreshadowing what their arguments will be and, in some trials, what the evidence will show. Often, these presentations take the form of a story, describing in narrative form the sequence of events that is central for the trial. These stories can have a large impact on jurors-so that, for example, jurors generally remember more of the trial evidence if they have one of these stories in mind from the trial's start. The reason is that jurors, listening to the trial testimony, can fit each new fact into the framework provided by the story, and this link to the framework supports memory.
For similar reasons, it's not surprising that jurors will remember more of the trial evi-dence if we make it easier for them to fit the evidence into a story. Concretely, they'll remember more if the testimony presents the trial evidence in "story sequence"-first, the earliest events in the story; then, later events; and so on.
But there's also a downside. Once jurors have adopted a story about the trial, evidence that's consistent with the story is more likely to be remembered; evidence inconsistent with the story is often forgotten. Also, jurors can sometimes "remember" evidence that actually wasn't presented during the trial but that is consistent with the story!
These findings are just what we'd expect, based on what we know about memory in other settings. But these facts are also troubling, because we would obviously prefer that jurors remember all the evidence-and remember it accurately. Perhaps, therefore, we should seek changes in courtroom procedures so that, in the end, the jurors' verdict will be based on an unbiased and complete recollection of the trial evidence. Also, it's important that jurors work together, as a group, to reach their verdict. So per-haps, during their deliberations, jury members can remind one another about points that some of them may have forgotten. Likewise, we might hope that jurors can correct one another's memory errors when they retire to the jury room to discuss the case.
This "memory repair" does happen to some extent, so deliberation does seem to im-prove jurors memory-but only up about the evidence are the people who are most confident that they recall the trial well. However, to a small extent. Why is it small? In the jury room, the people most likely to speak research tells us that confidence in one's memory isn't always an indication that the memory is accurate. Therefore, the people who speak up may not be the ones who remember the evidence correctly!
Overall, then, it seems that memory research highlights juror memory as yet another arena in which errors are possible. More positively, the research points improving the legal system might be possible-and are to another subject on which efforts at surely desirable.