Learning as Preparation for Retrieval
Putting information into long-term memory helps you only if you can retrieve that information later on. Otherwise, it would be like putting money into a savings account without the option of ever making withdrawals, or writing books that could never be read. But let’s emphasize that there are different ways to retrieve information from memory. You can try to recall the information (“What was the name of your tenth-grade homeroom teacher?”) or to recognize it (“Was the name perhaps Miller?”). If you try to recall the information, a variety of cues may or may not be available (you might be told, as a hint, that the name began with an M or rhymes with “tiller”).
In Chapter 6, we largely ignored these variations in retrieval. We talked as if material was well established in memory or was not, with little regard for how the material would be retrieved from memory. There’s reason to believe, however, that we can’t ignore these variations in retrieval, and in this chapter we’ll examine the interaction between how a bit of information was learned and how it is retrieved later. Crucial Role of Retrieval Paths In Chapter 6, we argued that when you’re learning, you’re making connections between the newly acquired material and other information already in your memory. These connections make the new knowledge “findable” later on Specifically, the connections serve as retrieval paths: When you want to locate information in memory, you travel on those paths, moving from one memory to the next until you reach the target material.
These claims have an important implication. To see this, bear in mind that retrieval paths-like any paths-have a starting point and an ending point: The path leads you from Point A to Point B That’s useful if you want to move from A to B, but what if you’re trying to reach B from somewhere else? What if you’re trying to reach Point B, but at the moment you happen to be nowhere close to Point A? In that case, the path linking A and B may not help you.
As an analogy, imagine that you’re trying to reach Chicago from somewhere to the west. For this purpose, what you need is some highway coming in from the west. It won’t help that you’ve constructed a wonderful road coming into Chicago from the east. That road might be valuable in other circumstances, but it’s not the path you need to get from where you are right now to where you’re heading.
Do retrieval paths in memory work the same way? If so, we might find cases in which your learning is excellent preparation for one sort of retrieval but useless for other types of retrieval-as if you’ve built a road coming in from one direction but now need a road from another direction. Do the research data show this pattern? Context-Dependent Learning Consider classic studies on context-dependent learning (Eich, 1980; Overton, 1985). In one such study, Godden and Baddeley (1975) asked scuba divers to learn various materials. Some of the divers learned the material while sitting on dry land; others learned it while underwater, hearing the material via a special communication set. Within each group, half of the divers were then tested while above water, and half were tested below (see Figure 7.2).
Underwater, the world has a different look, feel, and sound, and this context could easily influence what thoughts come to mind for the divers in the study. Imagine, for example, that a diver is feeling cold while underwater. This context will probably lead him to think “cold-related” thoughts, so those thoughts will be in his mind during the learning episode. In this situation, the diver is likely to form memory connections between these thoughts and the materials he’s trying to learn.
Let’s now imagine that this diver is back underwater at the time of the memory test. Most likely he’ll again feel cold, which may once more lead him to “cold-related” thoughts. These thoughts, in turn, are now connected (we’ve proposed) to the target materials, and that gives us what we want: The cold triggers certain thoughts, and because of the connections formed during learning, those thoughts can trigger the target memories.
Of course, if the diver is tested for the same memory materials on land, he might have other links other memory connections, that will lead to the target memories. Even so, on land the diver will be at a disadvantage because the “cold-related” thoughts aren’t triggered-so there will be no benefit from the memory connections that are now in place, linking those thoughts to the sought-after memories.
By this logic, we should expect that divers who learn material while underwater will remember the material best if they’re again underwater at the time of the test. This setting will enable them to use the connections they established earlier. In terms of our previous analogy, they’ve built certain highways, and we’ve put the divers into a situation in which they can use what they’ve built. And the opposite is true for divers who learned while on land; they should do best if tested on land. And that is exactly what the data show (see Figure 7.3).
Similar results have been obtained in other studies, including those designed to mimic the learning situation of a college student. In one experiment, research participants read a two-page article similar to the sorts of readings they might encounter in their college courses. Half the participants read the article in a quiet setting half read it in noisy circumstances. When later given a short-answer test, those who read the article in quiet did best if tested in quiet-67% correct answers, compared to 54% correct if tested in a noisy environment. Those who read the article in a noisy environment did better if tested in a noisy environment-62% correct, compared to 46 %. ( See Grant et al., 1998; also see Balch, Bowman, & Mohler, 1992; Cann & Ross, 1989; Schab, 1990; Smith, 1985; Smith & Vela, 2001.)
In another study, Smith, Glenberg, and Bjork (1978) reported the same pattern if learning and testing took place in different rooms -with the rooms varying in appearance, sounds, and scent. In this study, though, there was an important twist: In one version of the procedure, the participants learned materials in one room and were tested in a different room. Just before testing, however, the participants were urged to think about the room in which they had learned-what it looked like and how it made them feel. When tested, these participants performed as well as those for whom there was no room change (Smith, 1979). What matters, therefore, is not the physical context but the psychological context-a result that’s consistent with our account of this effect. AS a result, you can get the benefits of context-dependent learning through a strategy of context reinstatement -re- creating the thoughts and feelings of the learning episode even if you’re in a very different place at the time of recall. That’s because what matters for memory retrieval is the mental context, not the physical environment itself. e. Demonstration 7.1: Retrieval Paths and Connections Often, the information you seek in memory is instantly available. For example, if you try to remember your father’s name, or the capital of France, the information springs immediately into your mind. Other times, however, the retrieval of information is more difficult.
How well do you remember your childhood? For example, think back to the sixth grade: How many of your sixth-grade classmates do you remember? Try writing a list of all their names on a piece of paper. Do it now, before you read any farther.
Now, read the following questions:
· What house did you live in when you were in the sixth grade? Think about times that friends came over to your house. Does that help you remember more names?
· Were you involved in any sports in the sixth grade? Think about who played on the teams with you. Does that help you remember more names?
· Where did you sit in the classroom in sixth grade? Who sat at the desk on your left? Who sat at the desk on your right? In front of you? Behind? Does that help you remember more names?
· Did you ride the bus to school, or carpool, or walk? Were there classmates you often saw on your way to or from school? Does that help you remember more names?
· Was there anyone in the class who was always getting in trouble? Anyone who was a fabulous athlete? Anyone who was incredibly funny? Do these questions help you remember more names?
Chances are good that at least one of these strategies, which help you “work your way back” to the names, did enable you to come up with some classmates you’d forgotten-and perhaps helped you to recall some names you hadn’t thought about for years!
Apparently, these “extra” names were in your memory, even though you couldn’t come up with them at first. Instead, you needed to locate the right retrieval path leading to the memory, the right precisely, once you were at the right connection. Once that connection was in your mind (or, more “starting point” for the path), it led you quickly to the target memory. This is just what we would expect, based on the claims in Chapter 7. Encoding Specificity The results we’ve been describing also illuminate a further point: what it is that’s stored in memory. Let’s go back to the scuba-diving experiment. The divers in this study didn’t just remember the words they’d learned; apparently, they also remembered something about the context in which the learning took place. Otherwise, the data in Figure 7.3 (and related findings) make no sense: If the context left no trace in memory, there’d be no way for a return to the context to influence the divers later.
Here’s one way to think about this point, still relying on our analogy. Your memory contains both the information you were focusing on during learning, and the highways you’ve now built, leading toward that information. These highways- the memory connections-can of course influence your search for the target information; that’s what we’ve been emphasizing so far. But the connections can do more: They can also change the meaning of what is remembered, because in many settings “memory plus this set of connections” has a different meaning from “memory plus that set of connections.” This change in meaning, in turn, can have profound consequences for how you remember the past. In one of the early experiments exploring this point, participants read target words (e.g., “piano”) in one of two contexts: “The man lifted the piano” or “The man tuned the piano.” In each case, the sentence led the participants to think about the target word in a particular way, and it was this thought that was encoded into memory. In other words, what was placed in memory wasn’t just the word “piano.” Instead, what was recorded in memory was the idea of “piano as something heavy” or “piano as musical instrument.”
This difference in memory content became clear when participants were later asked to recall the to recall the target word target words. If they had earlier seen the “lifted” sentence, they were likely if given the cue “something heavy.” The hint “something with a nice sound” was much less effective. But if participants had seen the “tuned” sentence, the result reversed: Now, the “nice sound” hint was effective, but the “heavy” hint wasn’t (Barclay, Bransford, Franks, McCarrell, & Nitsch, 1974). In both cases, the cue was effective only if it was congruent with what was stored in memory.
Other experiments show a similar pattern, traditionally called encoding specificity (Tulving, 1983; also see Hunt & Ellis, 1974; Light & Carter-Sobell, 1970). This label reminds us that what you encode (ie., place into memory) is indeed specific-not just the physical stimulus as you encountered it, but the stimulus together with its context. Then, if you later encounter the stimulus in some other context, you ask yourself, “Does this match anything I learned previously?” and you correctly answer no. And we emphasize that this “no” response is indeed correct. It’s as if you had learned the word “other” and were later asked whether you’d been shown the word “the.” In fact, “the” does appear as part of “other”-because the letters t h e do appear within “other But it’s the whole that people learn, not the parts. Therefore, if you’ve seen “other,” it makes sense to deny that you’ve seen the”- or, for that matter, “he” or “her”-even though all these letter combinations are contained within “other” Learning a list of words works in the same way. The word “piano” was contained in what the research participants learned, just as “the” is contained in “other” What was learned, however, wasn’t just this word. Instead, what was learned was the broader, integrated experience: the word as the perceiver understood it. Therefore, “piano as musical instrument” isn’t what participants learned if they saw the “lifted” sentence, so they were correct in asserting that this item wasn’t on the earlier list (also see Figure 7.4).
e. Demonstration 7.2: Encoding Specificity The textbook argues that the material in your memory is not just a reflection of the sights and sounds you’ve experienced. Instead, the material in your memory preserves a record of how you thought about these sights and sounds, how you interpreted and understood them. This demonstration, illustrating this point, is little complicated because it has three separate parts. First, you’ll read a list of words. Next, you should leave the demonstration and go do something else for 15 to 20 minutes-run some errands, perhaps, or do a bit of your reading for next week’s class. After that, your memory will be tested.
Here is the list of words to be remembered. For each word, a short phrase or cue is provided to help you focus on what the word means. Read the phrase or cue out loud, then pause for a second, then read the word, then pause for another second to make sure you’ve really thought about the word. Then move on to the next. Ready? Begin. HIDE A day of the week: Thursday A large city: Tokyo
A government leader: King A sign of happiness: Smile
A type of bird: Cardinal A student: Pupil
A famous psychologist: Freud A long word: Notwithstanding
A mane item: Wine Has four wheels: Toyota
A personality trait: Charm A part of a bird: Bill
A vegetable: Cabbage A member of the family: Grandfather
Associated with heat: Stove A happy time of year: Birthday
A round object: Ball A part of a word: Letter
Found in the jungle: Leopard A tool: Wrench
A crime: Robbery Found next to a highway: Motel
A baseball position: Pitcher A type of sport equipment: Racket
Associated with cold: North Part of a building: Chimney
Song accompaniment: Banjo Made of leather: Saddle
Take to a birthday party: Present A tropical plant: Palm
A girl’s name: Susan A synonym for “big”: Colossal
A type of footgear: Boots Associated with lunch: Noon
A man-made structure: Bridge Part of the intestine: Colon
A weapon: Cannon A sweet food: Banana
An assertion possession: Mine
Now, what time is it? Close the list of words and go do something else for 15 minutes, then come back for the next part of this demonstration.
Next, we’re going to test your memory for the words you learned earlier. To guide your efforts at recall, a cue will be provided for each of the words. Sometimes the cue will be exactly the same as the cue you saw before, and sometimes it will be different. In all cases, though, the cue will be closely related to the target word. There are no misleading cues.
On a piece of paper, write down the word from the previous list that is related to the cue. Do not look at the previous list. If you can’t recall some of the words, leave those items blank
Here are the answers. Check which ones you got right.
These words are obviously in groups of three. For the second word in each group (“Tokyo,” “Cannon,” etc.), the cue is identical to the cue you saw on the very first list. How many of these (out of 13) did you get right?
For the first word in each group (“Smile,” “Banana.” etc.), the cue is closely linked to the one you saw at first (“A sign of happiness” was replaced with “A facial expression,” and so on). How many of these (out of 13) did you get right?
For the third word in each group (“Mine,” “Bridge,” etc.), the cue actually changed the meaning of the target word. (On the first list, “Bridge” was “A manmade structure,” not “A card game”; “Racket” was “A type of sports equipment,” not “A type of noise.) How many of these (out of 13) did you get right? Most people do best with the identical cues and a little worse with the closely linked cues. Most people recall the fewest words with the cues that changed the meaning. Is this the pattern of your results? If so, your data fit with what the chapter describes as encoding specificity. This term reflects the fact that what goes into your memory isn’t just the words; it’s more specific than that-the words plus some record of what you thought about each word. As a result, what’s in your memory is not (for example) the word “bridge.” If that were your memory, a cue like “card game” might do the trick Instead, what’s in your memory is something like “structure used to get across a river,” and to trigger that idea, you need a different cue.
Demonstration adapted from Thieman, T. J. (1984). Table 1, in A classroom demonstration of encoding specificity. Teaching of Psychology, 11(2), 102. Copyright 1984 Routledge. Reprinted by permission from the publisher (Taylor & Francis Group, http://www.informaworld.com) The Memory Network In Chapter 6, we introduced the idea that memory acquisition-and, more broadly, learning-involves the creation (or strengthening) of memory connections. In this chapter, we’ve returned to the idea of memory connections, building on the idea that these connections serve as retrieval paths guiding you toward the information you seek. But what are these connections? How do they work? And who (or what?) is traveling on these “paths”?
According to many theorists, memory is best thought of as a vast network of ideas. In later chapters, we’ll consider how exactly these ideas are represented (as pictures? as words? in some more abstract format?). For now, let’s just think of these representations as nodes within the network, just like the knots in a fisherman’s net. (In fact, the word “node” is derived from the Latin word for knot, nodus.) These nodes are tied to each other via connections we’ll call associations or associative links. Some people find it helpful to think of the nodes as being like light bulbs that can be turned on by incoming electricity, and to imagine the associative links as wires that carry the electricity. Spreading Activation Theorists speak of a node becoming activated when it has received a strong enough input signal. Then, once a node has been activated, it can activate other nodes: Energy will spread out from the just-activated node via its associations, and this will activate the nodes connected to the just- activated node.
To put all of this more precisely, nodes receive activation from their neighbors, and as more and more activation arrives at a particular node, the activation level for that node increases. Eventually the activation level will reach the node’s response threshold. Once this happens, we say that the node fires. This firing has several effects, including the fact that the node will now itself be a source of activation, sending energy to its neighbors and activating them. In addition, firing of the node will draw attention to that node; this is what it means to “find” a node within the network.
Activation levels below the response threshold, so-called subthreshold activation, also play an important role. Activation is assumed to accumulate, so that two subthreshold inputs may add together, in a process of summation, and bring the node to threshold. Likewise, if a node has been partially activated recently, it is in effect already “warmed up,” so that even a weak input will now be sufficient to bring it to threshold.
These claims mesh well with points we raised in Chapter 2, when we considered how neurons communicate with one another. Neurons receive activation from other neurons; once a neuron reaches its threshold, it fires, sending activation to other neurons. All of this is precisely parallel to the suggestions we’re describing here. Our current discussion also parallels claims offered in Chapter 4, when we described how a network of detectors might function in object recognition. In other words, the network linking memories to each other will resemble the networks we’ve described linking detectors to each other (e.g., Figures 4.9 and 4.10). Detectors, like memory nodes, receive their activation from other detectors; they can accumulate activation from different inputs, and once activated to threshold levels, they fire.
Returning to long-term storage, however, the key idea is that activation travels from node to node via associative links. As each node becomes activated and fires, it serves as a source for further activation, spreading onward through the network. This process, known as spreading activation, enables us to deal with a key question: How does one navigate through the maze of associations? If you start a search at one node, how do you decide where to go from there? The answer is that in most cases you don’t “choose” at all. Instead, activation spreads out from its starting point in all directions simultaneously, flowing through whatever connections are in place. Retrieval Cues This sketch of the memory network leaves a great deal unspecified, but even so it allows us to explain some well-established results. For example, why do hints help you to remember? Why, for example, do you draw a blank if asked, “What’s the capital of South Dakota?” but then remember if given the cue “Is it perhaps a man’s name?” Here’s one likely explanation. Mention of South Dakota will activate nodes in memory that represent your knowledge about this state. Activation will then spread outward from these nodes, eventually reaching nodes that represent the capital city’s name. It’s possible, though, that there’s only a weak connection between the SOUTH DAKOTA nodes and the nodes representing PIERRE. Maybe you’re not very familiar with South Dakota, or maybe you haven’t thought about this state’s capital for some time. In either case, this weak connection will do a poor job of carrying the activation, with the result that only a trickle of activation will flow into the PIERRE nodes, and so these nodes won’t reach threshold and won’t be “found.”
Things will go differently, though, if a hint is available. If you’re told, “South Dakota’s capital is also a man’s name,” this will activate the MAN’S NAME node. As a result, activation will spread out from this source at the same time that activation is spreading out from the SOUTH DAKOTA nodes. Therefore, the nodes for PIERRE will now receive activation from two sources simultaneously, and this will probably be enough to lift the nodes’ activation to threshold levels. In this way, question- plus-hint accomplishes more than the question by itself (see Figure 7.5).
Semantic Priming The explanation we’ve just offered rests on a key assumption-namely, the summation of subthreshold activation. In other words, we relied on the idea that the insufficient activation received from one source can add to the insufficient activation received from another source. Either source of activation on its own wouldn’t be enough, but the two can combine to activate the target nodes.
Can we document this summation more directly? In a lexical-decision task, research participants are shown a series of letter sequences on a computer screen. Some of the sequences spell words other sequences aren’t words (e.g., “blar, plome”). The participants’ task is to hit a “yes” button if the sequence spells a word and a “no” button otherwise. Presumably, they perform this task by “looking up” these letter strings in their “mental dictionary,” and they base their response on whether or not they find the string in the dictionary. We can therefore use the participants’ speed of response in this task as an index of how quickly they can locate the word in their memories.
In a series of classic studies, Meyer and Schvaneveldt (1971; Meyer, Schvaneveldt, & Ruddy, 1974) presented participants with pairs of letter strings, and participants had to respond “yes” if both strings were words and “no” otherwise. For example, participants would say “yes” in response to “chair, bread” but “no” in response to “house, fime.” Also, if both strings were words, sometimes the words were semantically related in an obvious way (e.g., “nurse, doctor”) and sometimes they weren’t (“cake. shoe”). Of interest was how this relationship between the words would influence performance. Consider a trial in which participants see a related pair, like “bread, butter.” To choose a response, they first need to “look up” the word “bread” in memory. This means they’ll search for, and presumably activate, the relevant node, and in this way they’ll decide that, yes, this string is a legitimate word. Then, they’re ready for the second word. But in this sequence, the node for BREAD (the first word in the pair) has just been activated. This will, we’ve hypothesized, trigger a spread of activation outward from this node, bringing activation to other, nearby nodes. These nearby nodes will surely include BUTTER, since the association between “bread” and “butter” is a strong one. Therefore, once the BREAD node (from the first word) is activated, some activation should also spread to the BUTTER node.
From this base, think about what happens when a participant turns her attention to the second word in the pair. To select a response, she must locate “butter” in men finds the relevant node), then she knows that this string, too, is a word, and she can hit the “yes” button. But the process of activating the BUTTER node has already begun, thanks to the (subthreshold) activation this node just received from BREAD. This should accelerate the process of bringing this node to threshold (since it’s already partway there), and so it will require less time to activate. As a result, we expect quicker responses to “butter” in this context, compared to a context If she finds this word (i.e. in which “butter” was preceded by some unrelated word. Our prediction, therefore, is that trials with related words will produce semantic priming. The “priming” indicates that a specific prior event (in this case, presentation of the first word in the pair) will produce a state of readiness (and, therefore, faster responding) later on. There are various forms of priming (in Chapter 4, we discussed repetition priming). In the procedure we’re considering here, the priming results from the fact that the two words in the pair are related in meaning- therefore, this is semantic priming.
The results confirm these predictions. Participants’ lexical-decision responses were faster by almost 100 ms if the stimulus words were related (see Figure 7.6), just as we would expect on the term model we’re developing. (For other relevant studies, including some alternative conceptions of priming, see Hutchison, 2003; Lucas, 2000.)
Before moving on, though, node activating nearby nodes-is not the whole story for memory search. As one complication, we should mention that this process of spreading activation-with one people have some the processes of reasoning (Chapter 12) and the mechanisms of executive control (Chapters 5 and 6). In addition, evidence suggests that once the spreading activation has begun, people have the option of “shutting down” some of this spread if they’re convinced that the wrong nodes are being activated (e.g., Anderson & Bell, 2001; Johnson & Anderson, 2004). Even so, spreading activation is a crucial degree of control over the starting points for their memory searches, relying on us understand why memory connections mechanism. It plays a central role in retrieval, and it helps are so important and so helpful. e. Demonstration 7.3: Spreading Activation in Memory Search On a piece of paper, list all of the men’s first names you can think of that are also verbs. For example, you can Mark something on paper; you shouldn’t Rob a bank. If you’re willing to ignore the spelling, you can Neil before the queen and Phil a bucket. How many other men’s names are also verbs? Spend a few minutes generating the list.
How do you search your memory to come up with these names? One possibility is that you first think of all the men’s names that you know, and then from this list you select the names that work as verbs. A different possibility reverses this sequence: You first think of all the verbs that you know and from this list you select the words that are also names. One last possibility is that you combine these steps, so that your two searches go on in parallel: In essence, you let activation spread out in your memory network from the MEN’S NAMES nodes, and at the same time you let activation spread out from the VERBS nodes. Then, you can just wait and see which nodes receive activation from both of these sources simultaneously. In fact, the evidence suggests that the third option (simultaneous activation from two sources) is the one you use. We can document this by asking a different group of people just to list all the verbs they know. When we do this, we find that some verbs come to mind only after a long delay-if at all. For example, if you’re just thinking of verbs, the verb “rustle” may not pop into your thoughts. If, therefore, you were trying to think of verbs-that-are-also-names by first thinking about verbs and then screening them, you’re unlikely to come up with “rustle” in your initial step (i.e., generating a list of verbs). Therefore, you won’t think about “rustle” in this setting, and so you won’t spot the fact that it’s also a man’s name (“Russell”). On this basis, this name won’t be one of the names on your list.
The reverse is also true. If you’re just thinking about men’s names, the name “Russell” may not spring to mind, and so, if this is the first step in your memory search (i.e., first generate a list of names; then screen it, looking for verbs), you won’t come up with this name in the first place. Therefore, you won’t consider this name, won’t see that it’s also a verb, and won’t put it on your list.
It turns out, though, that relatively rare names and rare verbs are often part of your final output. This makes no sense if you’re using a “two-step” procedure (first generate names, then screen them; would n up i he first or first generate verbs, then screen them) because the key w step of this process. But the result does make sense if your memory search combines the two steps. In that case, even though these rare items are only weakly activated by the MEN’S NAMES nodes, and only weakly activated by the VERBS nodes, they are activated perfectly well if they can receive energy from both time-and that is why these rare items come easily to mind. And, by the way, there are at least 50 men’s names that are also verbs, so keep hunting for them! It may help to remember that Americans Bob for apples at Halloween. Yesterday, I Drew a picture and decided to Stu the beef for dinner. I can Don a suit, Mike a speaker, Rush to an appointment, Flip a pancake, or Jimmy a locked door. These are just some of the names that could be on your list! e. Demonstration 7.4: Semantic Priming As Chapter 7 describes, searching thr ough long-term memory relies heavily on a process of spreading activation, with currently activated nodes sending activation outward to their neighbors. If this spread brings enough activation to the neighbors, then those nodes will themselves become activated. However, even if these nodes don’t receive enough activation to become activated themselves, the subthreshold activation still has important effects.
Here is a list of anagrams (words for which we’ve scrambled up the letters). Can you unscramble them to figure out what each of the words is?
Did you get them all? Continue in order to see the answers.
The answers, in no particular order, are “sea,” “shirt.” “victor,” “island,” “mountain,” “wave,” “pilot.” and-what? The last anagram in the list actually has two solutions: It could be an anagram for the boat used in North America to explore lakes and streams, or it could be an anagram for the body of water that sharks and whales and sea turtles live in. Which of these two solutions came to your mind? If you happen to be a devoted paddler, then good that “ocean” is the word “canoe” may have come rapidly into your thoughts. But the odds are that came to mind for you. Why is this? Several of the other words in this series (“sea,” “island” “mountain, “wave”) are semantically associated with “ocean.” Therefore, when you solved these earlier anagrams, you activated nodes for these words, and the activation spread outward from there to the neighboring nodes-including, probably, OCEAN. As a result, the word “ocean” was already primed when you turned to the last anagram, making it likely that this word, and not the legitimate alternative, would come into your thoughts as you unscrambled NOCAE. Different Forms of Memory Testing Let’s pause to review. In Chapter 6, we argued that learning involves the creation or strengthening of connections. This is why memory is promoted by understanding (because understanding consists, in large part, of seeing how new material is connected to other things you know). We also proposed that these connections later serve as retrieval paths, guiding your search through the vast warehouse that is memory. In this chapter, weve explored an important implication of this idea: that (like all paths) the paths through memory have both a starting point and an end point. Therefore, retrieval paths will be helpful only if you’re at the appropriate starting point; this, we’ve proposed, is the basis for the advantage produced by context reinstatement. And, finally, we’ve now started to lay out what these paths really are: connections that carry activation from one memory to another.
This theoretical base also helps us with another issue: the impact of different forms of memory testing. Both in the laboratory and in day-to-day life, you often try to recall information from memory. This means that you’re presented with a retrieval cue that broadly identifies the information you seek, and then you need to come up with the information on your own: “What was the name of that great restaurant your parents took us to?”; “Can you remember the words to that song?”; “Where were you last Saturday?” In other circumstances, you draw information from your memory via recognition. This term refers to cases in which information is presented to you, and you must decide whether it’s the sought-after information: “Is this the man who robbed you?”; “I’m sure I’ll recognize the street when we get there”; “If you let me taste that wine, I’ll tell you if it’s the same one we had last time.”
These two modes of retrieval-recall and recognition-are fundamentally different from each other. Recall requires memory search because you have to come up with the sought-after item on your own; you need to locate that item within memory. As a result, recall depends heavily on the so far. Recognition, in contrast, often depends memory connections we’ve been emphasizing sense of familiarity. Imagine, for example, that you’re taking a recognition test, and the fifth word on the test is “butler.” In response to this word, you might find yourself thinking, “I don’t recall seeing on a this word on the list, but this word feels really familiar, so I guess I must have seen it recently Therefore, it must have been on the list.” In this case, you don’t have source memory; that is, you don’t have any recollection of the source of your current knowledge. But you do have a strong sense of familiarity, and you’re willing to make an inference about where that familiarity came from. In other words, you attribute the familiarity to the earlier encounter, and thanks to this attribution you’ll probably respond “yes” on the recognition test. Familiarity and Source Memory We need our terms here, because source memory is actually a type of recall. Let’s say, for example, that you hear a song on the radio and say, “I know I’ve heard this song before because it feels familiar and I remember where I heard it.” In this setting, you’re able to remember the source of your familiarity, and that means you’re recalling when and where you encountered the song. On this basis, we don’t need any new theory to talk about source memory, because we can use the same theory that we’d use for other forms of recall. Hearing the song was the retrieval cue that launched a search through memory, a search that allowed you to identify the setting in which you last encountered the song. That search (like any search) was dependent on memory connections, and would be explained by the spreading activation process that we’ve already described.
But what about familiarity? What does this sort of remembering involve? As a start, let’s be clear that familiarity is truly distinct from source memory. This is evident in the fact that the two types of memory are independent of each other-it’s possible for an event to be familiar without any source memory, and it’s possible for you to have source memory without any familiarity. This independence is evident when you’re watching a movie and realize that one of the actors is familiar, but (sometimes with considerable frustration, and despite a lot of effort) you can’t recall where you’ve seen that actor before. Or you’re walking down the street, see a familiar face, and find yourself asking, “Where do I know that woman from? Does she work at the grocery store I shop in? Is she the driver of the bus I often take?” You’re at a loss to answer these questions; all you know is that the face is familiar.
In cases like these, you can’t “place” the memory; you can’t identify the episode in which the face was last encountered. But you’re certain the face is familiar, even though you don’t know why-a clear example of familiarity without source memory. The inverse case is less common, but it too can be demonstrated. For example, in Chapter 2 we discussed Capgras syndrome. Someone with this syndrome might have detailed, accurate memories of what friends and family members look like, and probably remembers where and when these other people were last encountered. Even so, when these other people are in view they seem hauntingly unfamiliar. In this setting, there is source memory without familiarity. (For further evidence-and a patient who, after surgery, has intact source memory but disrupted familiarity-see Bowles et al., 2007; also see Yonelinas & Jacoby, 2012.)
We can also document the difference between source memory and familiarity in another way. In many studies, (neurologically intact) participants have been asked, during a recognition test, to make a “remember/know” distinction. This involves pressing one button (to indicate “remember”) if they actually recall the episode of encountering a particular item, and pressing a different button (“know”) if they don’t recall the encounter but just have a broad feeling that the item must have been on the earlier list. With one response, participants are indicating that they have a source memory; with the other, they’re indicating an absence of source memory. Basically, a participant using the “know response is saying, “This item seems familiar, so I know it was on the earlier list even though I don’t remember the experience of seeing it” (Gardiner, 1988; Hicks & Marsh, 1999; Jacoby, Jones, & Dolan, 1998).
Researchers can use FMRI scans to monitor participants’ brain activity while they’re taking these memory tests, and the scans indicate that “remember” and “know” judgments depend on different brain areas. The scans show heightened activity in the hippocampus when participants indicate that they “remember” a particular test item, suggesting that this brain structure is crucial for source memory. In contrast, “know” responses are associated with activity in a different area-the anterior parahippocampus, with the implication that this brain site is crucial for familiarity. (See Aggleton & Brown, 2006; Diana, Yonelinas, & Ranganath, 2007; Dobbins, Foley, Wagner, & Schacter, 2002; Eldridge, Knowlton, Furmanski, Bookheimer, & Engel, 2000; Montaldi,, Spencer, Roberts, & Mayes, 2006; Wagner, Shannon, Kahn, & Buckner, 2005. Also see Rugg & Curran, 2007; Rugg & Yonelinas, 2003.)
Familiarity and source memory can also be distinguished during learning. If certain brain areas (e.g., the rhinal cortex) are especially active during learning, then the stimulus is likely to seem familiar later on. In contrast, if other brain areas (e.g., the hippocampal region) are particularly active during learning, there’s a high probability that the person will indicate source memory for that stimulus when tested later (see Figure 7.7). (See, e.g., Davachi & Dobbins, 2008; Davachi, Mitchell, & Wagner, 2003: Ranganath et al., 2003.)
We still need to ask, though, what’s going on in these various brain areas to create the relevant memories. Activity in the hippocampus is probably helping to create the memory connections we’ve been discussing all along, and it’s these connections, we’ve suggested, that promote source memory. But what about familiarity? What “record” does it leave in memory? The answer to this question leads us to a very different sort of memory. e. Demonstration 7.5: Studying for Different Types of Tests Chapter 7 emphasizes that recollection and familiarity are distinct types of memory-each obeys its own type of rules, and each is supported by its own brain circuits. With this context, think about the fact that when a teacher in school, or a professor in college, announces a test, students often ask about the format of the test. Will the test include multiple-choice questions? True-false questions? Short-answer questions? Essay questions?
Spend a minute thinking through whether the promised format of an your study strategies. Does the promised format influence how hard you study? Does it influence how you study or what you focus on during your studying?
Ask a few friends the same questions. Do they want to know, in advance of a test, what the test’s upcoming test influences format will be? Does it influence how they prepare for the test?
Then, as one last step: If you believe you study in the same way for different formats, is this consistent with the evidence in the chapter, distinguishing recollection and familiarity? If you think rou study differently for true-false or multiple-choice tests (both tests that hinge on recognition) on recall), do your choices about study than you do for short-answer or essay tests (both hinging strategy line up with what the chapter says about recognition and recall? We might mention that in a study done years ago, half of the participants were told that their memories would be assessed via a recall test; half were told they would be given a recognition test. Then, when the test actually took place, half of each group got the test format they expected; half did not. The data showed that participants did better with the recall test if this is what they’d expected (62% vs. 40% ) , and participants did better with the recognition test if that’s what they’d been led to expect (87 % vs. 67%) . Can you explain what’s going on here? Are there perhaps lessons for your own study strategies?
For more on this, see Tversky, B. (1973). Encoding processes in recognition and recall. Cognitive Psychology, 5, 275-287. Implicit Memory How can we find out if someone remembers a previous event? The obvious path is to ask her-“How did the job interview go?”; “Have you ever seen Casablanca?”; “Is this the book you told me about?” But at the start of this chapter, we talked about a different approach: We can expose someone to an event, and then later re-expose her to the same event and assess whether her response on the second encounter is different from the first. Specifically, we can ask whether the first encounter somehow primed the person-got her ready-for the second exposure. If so, it would seem that the person must retain some record of the first encounter- she must have some sort of memory. Memory without Awareness In a number of studies, participants have been asked to read through a list of words, with no indication that their memories would be tested later on. (They might be told that they’re merely checking the list for spelling errors.) Then, sometime later, the participants are given a lexical- decision task: They are shown a series of letter strings and, for each, must indicate (by pressing one button or another) whether the string is a word or not. Some of the letter strings in the lexical- decision task are duplicates of the words seen in the first part of the experiment (i.e., they were on the list participants had checked for spelling), enabling us to ask whether the first exposure somehow primed the participants for the second encounter. In these experiments, lexical decisions are quicker if the person has recently seen the test word; that is, lexical decision shows the pattern that in Chapter 4 we called “repetition priming” (e.g., Oliphant, 1983). Remarkably, this priming is observed even when participants have no recollection for having encountered the stimulus words before. To demonstrate this, we can show participants a list of words and then test them in two different ways. One test assesses memory directly, using standard recognition procedure: “Which of these words were on the list I showed you earlier?” The other test is indirect and relies on lexical decision: “Which of these letter strings form real words?” In this procedure, the two tests will yield different results. At a sufficient delay, the direct memory test is likely to show that the participants have completely forgotten the words presented earlier; their recognition performance is essentially random. According to the lexical-decision results however, the participants still remember the words-and so they show a strong priming effect. In this situation, then, participants are influenced by a specific past experience that they seem (consciously) not to remember at all-a pattern that some researchers refer to as “memory without awareness.” A different example draws on a task called word-stem completion. In this task, participants are given three or four letters and must produce a word with this beginning. If, for example, they’re given cla-, then “clam” or “clatter” would be acceptable responses, and the question of interest for us is which of these responses the participants produce. It turns out that people are more likely to offer a specific word if they’ve encountered it recently; once again, this priming effect is observed even if participants, when tested directly, show no conscious memory of their recent encounter with that word (Graf, Mandler, & Haden, 1982).
Results like these lead psychologists to distinguish two types of memory. Explicit memories are those usually revealed by direct memory testing-testing that urges participants to remember the past. Recall is a direct memory test; so is a standard recognition test. Implicit memories, however, are typically revealed by indirect memory testing and are often manifested as priming effects. In testing, participants’ current behavior is demonstrably influenced by a prior event, but this form they may be unaware of this. Lexical decision, word-stem completion, and many other tasks provide indirect means of assessing memory. (See, for example, Mulligan & Besken, 2013; for a different perspective on these data, though, see Cabeza & Moscovitch, 2012.)
How exactly is implicit memory different from explicit memory? We’ll say more about this question before we’re done; but first we need to say more about how implicit memory feels from the rememberer’s point of view. This will lead us back into our discussion of familiarity and source memory. False Fame In a classic research study, Jacoby, Kelley, Brown, and Jasechko (1989) presented participants with a were told nothing about a memory test; they thought list of names to read out loud. The participants the experiment was concerned with how they pronounced the names. Some time later, during the second step of the procedure, the participants were shown a new list of names and asked to rate each person on this list according to how famous each one was. The list included some real, very famous people; some real but not-so-famous people; and some fictitious names that the experimenters had invented. Crucially, the fictitious names were of two types: Some had occurred on the prior (“pronunciation”) list, and some were simply new names. A comparison between those two types will indicate how the prior familiarization (during the pronunciation task) influenced the participants’ judgments of fame. For some participants, the “famous” list was presented right after the “pronunciation” list; for other participants, there was a 24-hour delay between these two steps. To see how this delay matters, imagine that you’re a participant in the immediate-testing condition: When you see one of the fictitious-but-familiar names, you might decide, “This name sounds familiar, but that’s because I just saw it on the previous list.” In this situation, you have a feeling that the (familiar) name is distinctive, but you also know why it’s distinctive-because you remember your earlier encounter with the name. In other words, you have both a sense of familiarity and a source memory, so there’s nothing here to persuade you that the name belongs to someone famous, and you respond accordingly. But now imagine that you’re a participant in the other condition, with the 24-hour delay. Because of the delay, you may not recall the earlier episode of seeing the name in the pronunciation task. But the broad sense of familiarity remains anyway, so in this setting you might say, “This name rings a bell, and I have no idea why. I guess this must be a famous person.” And this is, in fact, the pattern of the data: When the two lists are presented one day apart, participants are likely to rate the made-up names as being famous.
Apparently, the participants in this study noted (correctly) that some of the names did “ring a bell” and so did trigger a certain feeling of familiarity. The false judgments of fame, however, come from the way the participants interpreted this feeling and what conclusions they drew from it. Basically, participants in the 24-hour-delay condition forgot the real source of the familiarity (appearance on a recently viewed list) and instead filled in a bogus source (“Maybe I saw this person in a movie?”). And it’s easy to see why they made this misattribution. After all, the experiment was described to them as being about fame, and other names on the list were actually those of famous people. From the participants’ point of view, therefore, it was reasonable to infer in this setting that any name that “rings a bell” belongs to a famous person. We need to be clear, though, that this misattribution is possible only because the feeling of familiarity produced by these names was relatively vague, and therefore open to interpretation. The suggestion, then, is that implicit memories may leave people with only a broad sense that a stimulus is somehow distinctive-that it “rings a bell” or “strikes a chord” What happens after this depends on how they interpret that feeling. Implicit Memory and the “Illusion of Truth” How broad is this potential for misinterpreting an implicit memory? Participants in one study heard a series of statements and had to judgehow interesting each statement was (Begg, Anas, & Farinacci, 1992). As an example, one sentence was “The average person in Switzerland eats about 25 pounds of cheese each year” (This is false; the average in 1992, when the experiment done, was closer to 18 pounds.) Another was “Henry Ford forgot to put a reverse gear in his first automobile.” (This is true.)
After hearing these sentences, the participants were presented with some more sentences, but now they had to judge the credibility of these sentences, rating them on a scale from certainly true to certainly false. However, some of the sentences in this “truth test” were repeats from the earlier presentation, and the question of interest is how sentence credibility is influenced by sentence familiarity. The result was a propagandist’s dream: Sentences heard before were more likely to be accepted as true; that is, familiarity increased credibility. (See Begg, Armour, & Kerr, 1985; Brown & Halliday, 1990; Fiedler, Walther, Armbruster, Fay, & Naumann, 1996; Moons, Mackie, & Garcia-Marques, 2009; Unkelbach, 2007.) This effect was found even when participants were warned in advance not to believe the sentences in the first list. In one procedure, participants were told that half of the statements had been made by men and half by women. The women’s statements, they were told, were always true; the men’s, always false. (Half the participants were told the reverse.) Then, participants rated how interesting the sentences were, with each sentence attributed to either a man or a woman: for example, “Frank Foster says that house mice can run an average of 4 miles per hour” or “Gail Logan says that crocodiles sleep with their eyes open.” Later, participants were presented with more sentences and had to judge their truth, with these new sentences including the earlier assertions about mice, crocodiles, and so forth.
Let’s focus on the sentences initially identified as being false-in our example, Frank’s claim about mice. If someone explicitly remembers this sentence (“Oh yes-Frank said such and such”), then he should judge the assertion to be false (“After all, the experimenter said that the men’s statements were all lies”). But what about someone who lacks this explicit memory? This person will have no conscious recall of the episode in which he last encountered this sentence (i.e., will have no source memory), and so he won’t know whether the assertion came from can’t use the source as a basis for judging the truthfulness of the sentence. But he might still have an implicit memory for the sentence left over from the earlier exposure (“Gee, that statement rings bell”), and this might increase his sense of the statement’s credibility (“I’m sure I’ve heard that somewhere before; I guess it must be true). This is exactly the pattern of the data: Statements plainly identified as false when they were first heard still created the so-called illusion of truth; that man or a woman. He therefore is, these statements were subsequently judged to be more credible than sentences never heard before. The relevance of this result to the political arena or to advertising should be clear. A newspaper headline might inquire, “Is Mayor Wilson a crook?” Or the headline might declare, “Known criminal claims Wilson is a crook!” In either case, the assertion that Wilson is a crook would become familiar. The Begg et al. data indicate that this familiarity will, by itself, increase the likelihood that you’ll later believe in Wilson’s dishonesty. This will be true even if the paper merely raised the question; it will be true even if the allegation came from a disreputable source. Malicious innuendo does, in fact produce nasty effects. (For related findings, see Ecker, Lewandowsky, Chang, & Pillai, 2014.)
Attributing Implicit Memory to the Wrong Source
Apparently, implicit memory can influence us (and, perhaps, bias us) in the political arena. Other evidence suggests that implicit memory can influence us in the marketplace-and can, for example, guide our choices when we’re shopping (e.g., Northup & Mulligan, 2013, 2014). Yet another example involves the justice system, and it’s an example with troubling implications. In an early study by Brown, Deffenbacher, and Sturgill (1977), research participants witnessed a staged crime. Two or three days later, they were shown “mug shots” of individuals who supposedly had participated in the crime. But as it turns out, the people in these photos were different from the actual “criminals”-no mug shots were shown for the truly “guilty” individuals. Finally, after four or five more days, the participants were shown a lineup and asked to select the individuals seen in Step 1-namely, the original crime (see Figure 7.8).
The data in this study show a pattern known as source confusion. The participants correctly realized that one of the faces in the lineup looked familiar, but they were confused about the source of the familiarity. They falsely believed they had seen the person’s face in the original “crime,” when, in truth, they’d seen that face only in a subsequent photograph. In fact, the likelihood of this error was quite high, with 29% of the participants (falsely) selecting from the lineup an individual they had seen only in the mug shots. (Also see Davis, Loftus, Vanous, & Cucciare, 2008; Kersten & Earles, 2017. For examples of similar errors that interfere with real-life criminal investigations, see Garrett, 2011. For a broader discussion of eyewitness errors, see Reisberg, 2014.) e. Demonstration 7.6: Priming from Implicit Memory Imagine that yesterday you read a particular word-“couch,” for example. This encounter with the word can change how you react to the word when you see it today. This will be true even if your memory contains no explicit record of yesterday’s event, so that you have no conscious memory of having read that particular word. Even without an explicit record, your unconscious memory can lead you to interpret the word differently the next time you meet it, or it can lead you to recognize the word more quickly. Implicit memories can also change your emotional response to a word. The emotional effect probably won’t be enough to make you laugh out loud or shed a tear when you see the word, but it may be enough to make the word seem more attractive to you than it would have been without the priming.
These implicit memory effects are, however, difficult to translate into quick demonstrations, because a classroom (or do-at-home) demonstration is likely to leave you with both an implicit and an explicit memory of the stimulus materials, and the explicit memory will overshadow the implicit memory. In other words, if an experience does leave you with an explicit memory, this record might lead you to overrule the implicit memory. Thus, your implicit memory might pull you toward a particular response, but your explicit memory might allow you to refuse that response and lead you to a different one instead-perhaps a response that’s not even close to the one favored by the implicit memory. We can, however, demonstrate something close to these effects. For example, write a short sentence using each of the following words.
Wind Bottle Close
Read Record Refuse
Dove Foot Desert
Pet Tear Lead
Write your sentences before you read on!
Several of thése words can be used in more than one way or have more than one meaning (think about how the “wind” blows and also how you “wind” up some types of toys). How did you use these items in your sentences? This use is likely to be guided to some extent by your memory: If you recently reada sentence like “He dove into the pool,” you’re more likely to use “dove” to indicate the activity rather than the bird. This effect will work even if you didn’t especially notice the word when you first saw it, and even if, now, you have no conscious recollection of recently seeing the word. In other words, these priming effects depend on implicit memory, not explicit.
It turns out that the opening paragraphs of this demonstration used the word “read” in the past tense, priming you to use the word in the past tense. Did you, in your sentence? The early paragraphs in this demonstration also primed you to use “record” as a noun, not a verb; “tear” as the name for the thing that comes out of your eye, not an action; “close” as an adjective, not a noun or a verb; and “refuse” as a verb, not a noun. You were also primed by the opening paragraphs to think of “lead” as a verb, not a noun. Did the priming work for you, guiding how you used the test words in the sentences you composed? Did you notice the primes? Did you remember them?
Let’s be clear, though, that these priming effects don’t work every time, simply because a number of other factors, in addition to priming, also influence how you use these words. Even so, the probability of your using the word a certain way is often changed by the prime, and so most people do show these priming effects. Theoretical Treatments of Implicit Memory One message coming from these studies is that people are often better at remembering that something is familiar than they are at remembering why it is familiar. This explains why it’s possible to have a sense of familiarity without source memory (“I’ve seen her somewhere before, but I can’t figure out where!”) and also why it’s possible to be correct in judging familiarity but mistaken in judging source.
In addition, let’s emphasize that in many of these studies participants are being influenced by memories they aren’t aware of. In some cases, participants realize that a stimulus is somehow familiar, but they have no memory of the encounter that produced the familiarity. In other cases, they don’t even have a sense of familiarity for the target stimulus; nonetheless, they’re influenced by their previous encounter with the stimulus. For example, experiments show that participants often prefer a previously presented stimulus over a novel stimulus, even though they have no sense of familiarity with either stimulus. In such cases, people have no idea that their preference is being guided by memory (Murphy, 2001; also Montoy, Horton, Vevea, Citkowicz, & Lauber, 2017).
It does seem, then, that the phrase “memory without awareness” is appropriate, and it does make sense to describe these memories as implicit memories. But how can we explain this form of unconscious “remembering”? Processing Fluency
Our discussion Chapters and 5 -has laid the foundation for a proposal about implicit memory. Let’s build the argument in steps.
When a stimulus arrives in front of your eyes, it triggers certain detectors, and these trigger other detectors, and these still others, until you recognize the object. (“Oh, it’s my stuffed bear, Blueberry”) We can think of this sequence as involving a “flow” of activation that moves from detector to detector. We could, if we wished, keep track of this flow and in this way identify the “path” that the activation traveled through the network. Let’s refer to this path as a processing pathway-the sequence of detectors, and the connections between detectors, that the activation flows through in recognizing a specific stimulus.
In the same way, we’ve proposed in this chapter that remembering often involves the activation of a node, and this node triggers other, nearby, no des so that they become activated; they trigger still other nodes, leading eventually to the information you seek in memory. So here, too, we can speak of a processing pathway-the sequence of nodes, and connections between nodes, that the activation flows through during memory retrieval.
We’ve also said the use of a processing pathway strengthens that pathway. This is because the baseline activation level of nodes or detectors increases if the nodes or detectors have been used frequently in the past, or if they’ve been used recently. Likewise, connections (between detectors or nodes) grow stronger with use. For example, by thinking about the link between, say, “Jacob” and “Boston,” you can strengthen the connection between the corresponding nodes, and this will help you remember that your friend Jacob comes from Boston. Now, let’s put the pieces together. Use of a processing pathway strengthens the pathway. As a result, the pathway will be a bit more efficient, a bit faster, the next time you use it. Theorists describe this fact by saying that use of a pathway increases the pathway’s processing fluency-that is, the speed and ease with which the pathway will carry activation.
In many cases, this is all the theory we need to explain implicit memory effects. Consider implicit memory’s effect on lexical decision. In this procedure, you first are shown a list of words, including the word “bubble.” Then, we ask you to do the lexical-decision task, and we find that you’re faster for words (like “bubble”) that had been included in the earlier list. This increase in speed provides evidence for implicit memory, and the explanation is straightforward. When we show you “bubble” early in the experiment, you read the word, and this involves activation flowing through the appropriate processing pathway for this word. This warms up the pathway, and as a result the functioning will be more fluent the next time you use it. Of course, when “bubble” shows up later as part of the lexical-decision task, it’s handled by the same (now more fluent) pathway, and so the n’s word is processed more rapidly-exactly the outcome that we’re trying to explain. For other implicit-memory effects, though, we need a further assumption- namely, that people are sensitive to the degree of processing fluency. That is, just as people can tell whether they’ve lifted a heavy carton or a lightweight one, or whether they’ve answered an easy question (“What’s 2 + 2?”) or a harder one (“What’s 17 3 19?”), people also have a broad sense of when they have perceived easily and when they have perceived only by expending more effort. They likewise know when a sequence of thoughts was particularly fluent and when the sequence was labored.
This fluency, however, is perceived in an odd way. For example, when a stimulus is easy to perceive, you don’t experience something like “That stimulus sure was easy to recognize!” Instead, you merely register a vague sense of specialness. You feel that the stimulus “rings a bell.” No matter how it is described, though, this sense of specialness has a simple cause-namely, the detection of fluency, created by practice.
There’s one complication, however. What makes a stimulus feel “special” may not be fluency itself. Instead, people seem sensitive to changes in fluency (e.g., they notice if it’s a little harder to recognize a face this time than it was in the past). People also seem to notice discrepancies between how easy (or hard) it was to carry out some mental step and how easy (or hard) they expected it to be (Wanke & Hansen, 2015; Whittlesea, 2002). In other words, a stimulus is registered as distinctive, or “rings a bell.” when people detect a change or a discrepancy between experience and expectations. To see how this matters, imagine that a friend unexpectedly gets a haircut (or gets new eyeglasses, or adds or removes some facial hair). When you see your friend, you realize immediately that something has changed, but you’re not sure what. You’re likely those new glasses?”) and get a scornful answer. (“No, you’ve seen these glasses a hundred times over the last year.”) Eventually your friend tells you what the change is-pointing out that you failed to to ask puzzled questions (“Are notice that he’d shaved off his mustache (or some such).
What’s going on here? You obviously can still recognize your friend, but your recognition is less fluent than in the past because of the change in your friend’s appearance, and you notice this change -but then are at a loss to explain it (see Figure 7.9).
On all of these grounds, we need another step in our hypothesis, but it’s a step we’ve already introduced: When a stimulus feels special (because of a change in fluency, or a discrepancy between the fluency expected and the fluency experienced), you often want to know why. Thus the vague feeling of specialness (again, produced by fluency) can trigger an attribution process, as you ask, “Why did that stimulus stand out?”
In many circumstances, you’ll answer this question correctly, and so the specialness will be (accurately) interpreted as familiarity and attributed to the correct source. (“That woman seems distinctive, and I know why: It’s the woman I saw yesterday in the dentist’s office.”) Often, you make this attribution because you have the relevant source memory-and this memory guides you in deciding why a stimulus (a face, a song, a smell) seems to stand out. In other cases, you make a reasonable inference, perhaps guided by the context. (“I don’t remember where I heard this joke before, but it’s the sort of joke that Conor is always telling joke is familiar.”) In other situations, though, things don’t go so smoothly, and so-as we have seen- so I bet it’s one of his and that’s why the people sometimes misinterpret their own processing fluency, falling prey to the errors and illusions we have been discussing. The Nature of Familiarity
All of these points provide us-at last-with a proposal for what “familiarity” is, and the proposal is surprisingly complex. You might think that familiarity is simply a feeling that’s produced more or less directly when you encounter a stimulus you’ve met before. But the research findings described in the last few sections point toward a different proposal-namely, that “familiarity” is more like a conclusion that you draw rather than a feeling triggered by suggests that a stimulus will seem familiar whenever the following list of requirements is met: First, you have encountered the stimulus before. Second, because of that prior encounter (and the “practice” it provided), your processing of that stimulus is now faster and more efficient; there is, in other words, an increase in processing fluency. Third, you detect that increased fluency, and this leads you to register the stimulus as somehow distinctive or special. Fourth, you try to figure out a stimulus. Specifically, the evidence why the stimulus seems special, and you reach a particular conclusion-namely, that the stimulus has this distinctive quality because it’s a stimulus you’ve met before in some prior episode (see Figure 7.10).
Let’s be clear, though, that none of these steps happens consciously-you’re not aware of seeking an interpretation or trying to explain why a stimulus feels distinctive. All you experience consciously is the end product of all these steps: the sense that a stimulus feels familiar. Moreover, this conclusion about a stimulus isn’t one you draw capriciously; instead, you’re likely to arrive at this conclusion and decide a stimulus is familiar only when you have supporting information. Thus, imagine that you encounter a stimulus that “rings a bell.” As we mentioned before, you’re likely to decide the stimulus is familiar if you also have an (explicit) source memory, so that you can recall where and when you last encountered that stimulus. You’re also more likely to decide a stimulus is familiar if the surrounding circumstances support it. For example, if you’re asked, “Which of these words were on the list you saw earlier?” the question itself gives you a cue that some of the words were recently encountered, and so you’re more likely to attribute fluency to that encounter.
The fact remains, though, that judgments like these sometimes go astray, which is why we need this complicated theory. We’ve considered several cases in which a stimulus is objectively familiar (you’ve seen it recently) but doesn’t feel familiar-just as our theory predicts. In these cases, you detect the fluency but attribute it to some other source. (“That melody is lovely” rather than “The melody is familiar.”) In other words, you go through all of the steps shown in the top of Figure 7.10 specific prior event, and so you don’t except for the last two: You don’t attribute the fluency to a experience a sense of familiarity. We can also find the opposite sort of case-in which a stimulus is not familiar (i.e., you’ve not seen it recently) but feels familiar anyhow-and this, too, fits with the theory. This sort of illusion of familiarity can be produced if the processing of a completely novel stimulus is more fluent than you expected-perhaps because (without telling you) we’ve sharpened the focus of a computer display or presented the stimulus for a few milliseconds longer than other stimuli you’re inspecting (Jacoby & Whitehouse, 1989; Whittlesea, 2002; Whittlesea, Jacoby, & Girard, 1990). Cases like these can lead to the situation shown in the bottom half of Figure 7.10. And as our theory predicts, these situations do produce an illusion: Your processing of the stimulus is unexpectedly fluent; you seek an attribution for this fluency, and you’re fooled into thinking the stimulus is familiar-so you say you’ve seen the stimulus before, when in fact you haven’t. This illusion is a powerful confirmation that the sense of familiarity does rest on processes like the ones we’ve described. (For more on fluency, see Besken & Mulligan, 2014; Griffin, Gonzalez, Koehler, & Gilovich, 2012; Hertwig, Herzog, Schooler, & Reimer, 2008; Lanska, Olds, & Westerman, 2013; Oppenheimer, 2008; Tsai & Thomas, 2011. For a glimpsse of what fluency amounts to in the nervous system, see Knowlton & Foerde, 2008.) The Hierarchy of Memory Types Clearly, we’re often influenced by the past without being aware of that influence. We often respond differently to familiar stimuli than we do to novel stimuli, even if we have no subjective feeling of familiarity. On this basis, it seems that our conscious recollection seriously underestimates what’s in our memories, and research has documented many ways in which unconscious memories influence what we do, think, and feel.
In addition, the data are telling us that there are two different kinds of memory: one type (“explicit”) is conscious and deliberate, the other (“implicit”) is typically unconscious and automatic. These two broad categories can be further subdivided, as shown in Figure 7.11. Explicit memories can be subdivided into episodic memories (memory for specific events) and semantic memory (more general knowledge). Implicit memory is often divided into four subcategories, as shown in the figure. Our emphasis here has been on one of the subtypes-priming-largely because of its role in producing the feeling of familiarity. However, the other subtypes of implicit memory are also important and can be distinguished from priming both in terms of their functioning (i.e., they follow somewhat different rules) and in terms of their biological underpinnings.
Some of the best evidence for these distinctions, though, comes from the clinic, not the laboratory. In other words, we can learn a great deal about these various types of memory by considering individuals who have suffered different forms of brain damage. Let’s look at some of that evidence. Amnesia As we have already mentioned, a variety of injuries or illnesses can lead to a loss of memory, or amnesia. Some forms of amnesia are retrograde, meaning that they disrupt memory for things learned prior to the event that initiated the amnesia (see Figure 7.12). Retrograde amnesia is often caused by blows to the head; the afflicted person is unable to recall events that occurred just before the blow. Other forms of amnesia have the reverse effect, causing disruption of memory for experiences after the onset of amnesia; these are cases of anterograde amnesia. (Many cases of amnesia involve both retrograde and anterograde memory loss.)
Disrupted Episodic Memory, but Spared Semantic Memory
Studies of amnesia can teach us many things. For example, do we need all the distinctions shown in Figure 7.11? Consider the case of Clive Wearing, whom we met in the opening to Chapter 6. (You can find more detail about Wearing’s case in an extraordinary book by his wife-see Wearing, 2011.) Wearing’s episodic memory is massively disrupted, but his memory for generic information, as well as his deep love for his wife, seem to be entirely intact. Other patients show the reverse pattern- disrupted semantic memory but preserved episodic knowledge. One patient, for example, suffered damage (from encephalitis) to the front portion of her temporal lobes. As a consequence, she lost her memory of many common words, important historical events, famous people, and even the fundamental traits of animate and inanimate objects. “However, when asked about her wedding and honeymoon, her father’s illness and death, or other specific past episodes, she readily produced detailed and accurate recollections” (Schacter, 1996, p. 152; also see Cabeza & Nyberg, 2000). (For more on amnesia, see Brown, 2002; Clark & Maguire, 2016; Kopelman & Kapur, 2001; Nadel & Moscovitch, 2001; Riccio, Millin, & Gisquet-Verrier, 2003.)
These cases (and other evidence too; see Figure 7.13) provide the double dissociation that demands a distinction between episodic and semantic memory. It’s observations like these that force us to the various distinctions shown in Figure 7.11. (For evidence, though, that episodic and semantic memory are intertwined in important ways, see McRae & Jones, 2012.)
We’ve already mentioned the patient known as H.M. His memory loss was the result of brain surgery in 1953, and over the next 55 years (until his death in 2008) H.M. participated in a vast number of studies. Some people suggest he was the most-studied individual in the entire history of psychology (which is one of the reasons we’ve returned to his case several times). In fact, the data gathering continued after H.M.’s death-with careful postmortem scrutiny of his brain. (For a review of H.M’s case, see Corkin, 2013; Milner, 1966, 1970; also O’Kane, Kensinger, & Corkin, 2004; Skotko et al., 2004; Skotko, Rubin, & Tupler, 2008.)
After his surgery, H.M. was still able to recall events that took place before the surgery-and so his amnesia was largely anterograde, not retrograde. But the amnesia was severe. Episodes he had experienced after the surgery, people he had met, stories he had heard-all seemed to leave no lasting record, as though nothing new could get into his long-term storage.
H.M. could hold a mostly normal conversation (because his working memory was still intact), but his deficit became instantly clear if the conversation was interrupted. If you spoke with him for a while, then left the room and came back 3 or 4 minutes later, he seemed to have totally forgotten that the earlier conversation ever took place. If the earlier conversation was your first meeting with H.M., he would, after the interruption, be certain he was now meeting you for the very first time.
A similar amnesia has been found in patients who have been longtime alcoholics. The problem isn’t the alcohol itself; the problem instead is that alcoholics tend to have inadequate diets, getting most of their nutrition from whatever they’re drinking. It turns out, though, that most alcoholic beverages are missing several key nutrients, including vitamin B1 (thiamine). As a result, longtime alcoholics are vulnerable to problems caused by thiamine deficiency, including the disorder known as Korsakoffs syndrome (Rao, Larkin, & Derr, 1986; Ritchie, 1985). Patients suffering from Korsakoffs syndrome seem similar to H.M. in many ways. They typically have no problem remembering events that took place before the onset of alcoholism. They can also maintain current topics in mind as long as there’s no interruption. New information, though, if displaced from the mind, seems to be lost forever. Korsakoffs patients who have been in the hospital for decades will casually mention that they arrived only a week ago; if asked the name of the current president or events in the news, they unhesitatingly give answers appropriate for two or three decades earlier, whenever the disorder began (Marslen-Wils on & Teuber, 1975; Seltzer & Benson, 1974).
Anterograde Amnesia: What Kind of Memory Is Disrupted?
At the chapter’s beginning, we alluded to other evidence that complicates this portrait of anterograde amnesia, and it’s evidence that brings us back to the distinction between implicit and explicit memory. As it turns out, some of this evidence has been available for a long time. In 1911, the Swiss psychologist Edouard Claparède (1911/1951) reported the following incident. He was introduced to a young woman suffering from Korsakoffs amnesia, and he reached out to shake her hand. However, Claparède had secretly positioned a pin in his own hand so that when they clasped hands the patient received a painful pinprick. (Modern investigators would regard this experiment as a cruel violation of a patient’s rights, but ethical standards were much, much lower in 1911.) The next day, Claparède returned and reached out to shake hands with the patient. Not surprisingly, she gave no indication that she recognized Claparède or remembered anything about the prior encounter. (This confirms the diagnosis of amnesia.) But just before their hands touched, the patient abruptly pulled back and refused to shake hands with Claparède. He asked her why the patient said vaguely, “Sometimes pins are hidden in people’s hands.”
What was going on here? On the one side, this patient seemed to have no memory of the prior encounter with Claparède. She certainly didn’t mention it in explaining her refusal to shake hands and when questioned closely about the earlier encounter, she showed no knowledge of it. But, on the other side, she obviously remembered something about the painful pinprick she’d gotten the d after some confusion previous day. We see this clearly in her behavior.
A related pattern occurs with other Korsakoff’s patients. In one of the early demonstrations of this point, researchers used a deck of cards like those used in popular trivia games. Each card contained a question and some possible answers, in a multiple-choice format (Schacter, Tulving, & Wang, 1981). The experimenter showed each card to a Korsakoffs patient, and if the patient didn’t know the answer, he was told it. Then, outside of the patient’s view, the card was replaced in the deck, guaranteeing that the same question would come up again in a few minutes.
When the question did come up again, the patients in this study were likely to get it right-and so apparently had learned the answer in the previous encounter. Consistent with their diagnosis though, the patients had no recollection of the learning: They were unable to explain why their answers were correct. They didn’t say, “I know this bit of trivia because the same question came up just five minutes ago.” Instead, patients were likely to say things like “I read about it somewhere” or “My sister once told me about it.”
Many studies show similar results. In setting after setting, Korsakoffs patients are unable to recall episodes they’ve experienced; they seem to have no explicit memory. But if they’re tested indirectly, we see clear indications of memory-and so these patients seem to have intact implicit memories. (See, e.g., Cohen & Squire, 1980; Graf & Schacter, 1985; Moscovitch, 1982; Schacter, 1996; Schacter & Tulving, 1982; Squire & McKee, 1993.) In fact, in many tests of implicit memory, amnesic patients seem indistinguishable from ordinary individuals. Can There Be Explicit Memory without Implicit?
We can also find patients with the reverse pattern-intact explicit memory, but impaired implicit. One study compared amygdala with a second patient who had the opposite pattern: damage to the amygdala but not the a patient who had suffered brain damage to the hippocampus but not the hippocampus (Bechara et al., 1995). These patients were exposed to a series of trials in which a particular stimulus (a blue light) was reliably followed by loud boat horn, while other stimuli (green, yellow, or red lights) were not followed by the horn. Later on, the patients were exposed to the blue light on its own, and their bodily arousal was measured; would they show a fright reaction in response to this stimulus? In addition, the patients were asked directly, “Which color was followed by the horn?”
The patient with damage to the hippocampus did show a fear reaction to the blue light-assessed via the skin conductance response (SCR), a measure of bodily arousal. As a result, his data on this measure look just like results for control participants (i.e., people without brain damage; see Figure 7.14). However, when asked directly, this patient couldn’t recall which of the lights had been associated with the boat horn.
In contrast, the patient with damage to the amygdala showed the opposite pattern. She was able to report that just one of the lights had been associated with the horn and that the light’s color had been blue-demonstrating fully intact explicit memory. When presented with the blue light, however she showed no fear response. Optimal Learning Before closing this chapter, let’s put these amnesia findings into the broader context of the chapter’s main themes. Throughout the chapter, we’ve suggested that we cannot make claims about learning or memory acquisition without some reference to how the learning will be used later on. For example, whether it’s better to learn underwater or on land depends on where you will be tested. Whether it’s better to learn while listening to jazz or while sitting in a quiet room depends on the acoustic background of the memory test environment.
These ideas are echoed in the neuropsychology data. Specifically, it would be misleading to say that brain damage (whether from Korsakoffs syndrome or some other source) ruins someone’s ability to create new memories. Instead, brain damage is likely to disrupt some types of learning but not others, and how this matters for the person depends on how the newly learned material will be accessed. Thus, someone who suffers hippocampal damage will probably appear normal on an indirect memory test but seem amnesic on a direct test, while someone who suffers amygdala damage will probably show the reverse pattern. All these points enormously important for our theorizing about memory, but they also have a practical implication. Right now, you are reading this material and presumably want to remember it later on. You’re also encountering new material in other settings (perhaps in other classes you’re taking), and surely you want to remember that as well. How should you study all of this information if you want the best chances of retaining it for later use?
At one level, the message from this chapter might be that the ideal form of learning would be one that’s “in tune with” the approach to the material that you’ll need later. If you’re going to be tested explicitly, you want to learn the material in a way that prepares you for that form of retrieval. If you’ll be tested underwater or while listening to music, then, again, you want to learn the material in a way that prepares you for that context and the mental perspective it produces. If you’ll need source memory, then you want one type of preparation; if you’ll need familiarity, you might want a different type of preparation.
The problem, though, is that during learning, you often don’t know how you’ll be approaching the material later-what the retrieval environment will be, whether you’ll need the information implicitly or explicitly, and so on. As a result, maybe the best strategy perspectives. To revisit our earlier analogy, imagine that you know at some point in the future you’ll want to reach Chicago, but you don’t know yet whether you’ll be approaching the city from the north, the south, or the west. In that case, your best bet might be to build multiple highways, so that would be to use multiple learnin you can reach your goal from any direction. Memory works the same way. If you initially think about topic in different ways and in relation to many other ideas, then you’ll establish many paths leading to the target material-and so you’ll be able to access that material from many different perspectives. The practical message from this chapter, then, is that this multiperspective approach may provide the optimal learning strategy. e. Demonstration 7.7: Unconscious “Motor Memories” One of the important messages in Chapter 7 is that some memories seem not to be conscious and are revealed only through indirect testing. The chapter focuses on one type of unconscious memories-that is, memories typically revealed through priming effects of one sort or another. But there are other types of unconscious memories-including ones that seem to be represented through habitual motions.
For example, you probably have keys that open a number of locked doors, but do you remember which way each key turns in each door? Many people “recall” this information by pantomiming the relevant action, pretending to insert a key into an imagined lock. Can you use this strategy to remember which way the key turns in your own front door? Or in the lock of some other door that you often have to open?
As you go through your daily routine, you likely also have to turn various knobs to open cabinets or to turn on lights. Without moving your hands, can you recall which way the knobs turn? Can you help yourself remember by pantomiming the action?
In the same way, do you remember where the individual letters are on a keyboard, whether it’s the keyboard for your computer or the one you use on your smartphone? Where is the key for “j? The key for “e”? Again, many people “recall” this information by pretending to type something, using an imagined keyboard in the air. Can you use this strategy to remember where various keys are located? How is this type of memory similar to what the chapter calls “explicit” memory? How is this type of memory different from explicit memory? How is it similar to, and different from, the sort of priming effects described in the book under the broad banner of “implicit” memory? COGNITIVE PSYCHOLOGY AND EDUCATION familiarity can be treacherous Sometimes you see a picture of someone and immediately say, “Gee-she looks familiar!” This seems like a simple and direct reaction to the picture, but the chapter describes how complicated familiarity really is. Indeed, the chapter makes it clear that we can’t think of familiarity just as a “feeling” somehow triggered by a stimulus. Instead, familiarity seems more like a conclusion that you draw at the end of a many-step process. As a result of these complexities, errors about familiarity are possible: cases in which a stimulus feels familiar even though it’s not, or cases in which you correctly realize that the stimulus is familiar but then make a mistake about why it’s familiar.
These points highlight the dangers, for students, of relying on familiarity. As one illustration, consider the advice that people sometimes give for taking a multiple-choice test. They tel inclination” or “Choose the answer that feels familiar.” In some cases these strategies will you, “Go with your first help, because sometimes the correct answer will indeed feel familiar. But in other cases these strategies can lead you astray, because the answer you’re considering may seem familiar for a bad reason. What if your professor once said, “One of the common mistakes people make is to believe. . ” and then talked about the claim summarized in the answer you’re now considering? Alternatively, what if the answer seems familiar because it resembles the correct answer but is, in some crucial way, different (and therefore from the correct answer mistaken)? In either of these cases, your sense of familiarity might lead you to a wrong answer.
Even worse, one study familiarized people with phrases like “the record for tallest pine tree” Because of this exposure, these people were later more likely to accept as true a longer phrase, such as “the record for tallest pine tree is 350 feet.” Why? Because they realized that (at least) part of the sentence was familiar and therefore drew the reasonable inference that they must have encountered the entire sentence at some previous point. The danger here should be obvious: On a multiple- choice test, part of an incorrect option may be an exact duplicate of some phrase in your reading; if so, relying on familiarity will get you into trouble! (And, by the way, this claim about pines is false the tallest pine tree-a sugar pine-is only about 273 feet tall.)
As a different concern, think back to the end-of-chapter essay for Chapter 6. There, we noted that one of the most common study strategies used by students is to read and reread their notes, or read and reread the textbook. This strategy turns out not to help memory very much, and other strategies are demonstrably better. But, in addition, the rereading strategy can actually hurt you. Thanks to the rereading, you become more and more familiar with the materials, which makes it easy to interpret this familiarity as mastery. But this is a mistake, and because of the mistake familiarity can sometimes lead students to think they’ve mastered material when they haven’t. causing them to end their study efforts too soon. What can you do to avoid all these dangers? You’ll do much better job of assessing your own mastery if, rather than relying on familiarity, you give yourself some sort of quiz (perhaps one you find in the textbook, or one that a friend creates for you). More broadly, it’s valuable to be alert to the various complexities associated with familiarity. After all, you don’t want to ignore familiarity, multiple-choice question but option B seems somehow familiar, then choosing B may be your only path forward. But given the difficulties we’ve mentioned here, it may be best to regard familiarity just as a weak clue because sometimes it’s all you’ve got. If you really don’t know the answer to a about the past and not as a guaranteed indicator. That attitude may encourage the sort of caution that will allow you to use familiarity without being betrayed by it. COGNITIVE PSYCHOLOGY AND THE LAW the “cognitive interview” Police investigations often depend on eyewitness reports, but what can the police do if witnesses insist they can’t remember the event and can’t answer the police questions? Are there steps we can take to help witnesses remember?
A number of exotic procedures have been proposed to promote witness recollection, including hypnosis and the use of memory-enhancing medications. Evidence suggests, however, that these procedures provide little benefit (and may, in some settings, actually harm memory). Indeed “hypnotically enhanced memory” is inadmissible as trial evidence in most jurisdictions.
However, there is a much more promising approach. The “cognitive interview” is a technique developed by psychologists with the aim of improving eyewitness memory; a parallel procedure has been developed for interviewing children who have been witnesses to crimes. A related procedure is used in England (the so-called P.E.A.C.E. procedure) for questioning suspects.
A considerable quantity of evidence suggests that the cognitive interview is successful-it does help people to remember more. It’s gratifying, then, that the cognitive interview has been adopted by a number of police departments as their preferred interview technique. How does the cognitive interview work? Let’s start with the fact that sometimes you cannot remember things simply because you didn’t notice them in the first place, and so no record of the desired information was ever placed in long-term storage. In this situation, no procedure-whether it’s the cognitive interview, or hypnosis, or simply trying really hard to recall-can locate information that isn’t there to be located. You cannot get water out of an empty bottle, and you cannot read words off a blank page. In the same way, you cannot recall information that was never placed in memory to begin with.
In other cases, though, the gaps in your recollection have a different source. The desired information is in memory, but you’re unable to find it. (We have more to say about this point in Chapter 8, when we discuss theories of forgetting.) To overcome this problem, the cognitive interview relies on context reinstatement. The police investigator urges the witness to think back to the setting of the target event: How did the witness feel at the time of the crime? What was the physical setting? What was the weather? As Chapter 7 discusses, these steps are likely to put the witness back into the same mental state, the same frame of mind, that he or she had at the time of the crime-and in many cases, these steps will promote recall.
Moreover, the chapter’s discussion of retrieval paths leads to the idea that sometimes you’ll recall a memory only if you approach the memory from the right angle-using the proper retrieval path. But how do you choose the proper path? The cognitive interview builds on the simple idea that you don’t have to choose. Instead, you can try recalling the events from lots of different angles (via lots of different paths) in order to maximize your chances of finding a path that leads to the desired information.
For example, the cognitive interview encourages witnesses first to recount the event from its start to its end, and then recount it in reverse sequence from the end back to the beginning. Sometimes witnesses are also encouraged to take a different spatial perspective: “You just told me what you saw; try to remember what Joe would have seen, from where he was standing”
In short, the cognitive interview builds on principles that are well established in research-the or the importance of retrieval paths. It’s no surprise, role of context reinstatement, for example, on mechanisms that we therefore, that the cognitive interview is effective; the procedure capitalizes know to be helpful.
The cognitive interview was, as we’ve said, designed to help law-enforcement professionals in their investigations. Note, though, that the principles involved here are general ones, and they can be useful in many other settings. Imagine a physician trying to get as complete a medical history as possible: “When did the rash first show up? Is it worse after you’ve eaten certain foods?” Or think anything about a novice repair person trying to recall what she learned in training: “Did they tell me about this particular error code?” Or think about your own situation when you’re trying to recall, say, what you read in the library last week. The ideas built into the cognitive interview are useful in these settings as well-in fact, they’re useful for anyone who needs to draw as much information from memory as possible. COGNITIVE PSYCHOLOGY AND THE LAW in-court identifications Imagine that you witness a crime. The police suspect that Robby Robber was the perpetrator, so they place Robby’s picture onto a page together with five other photos, and they show you this “photospread.” You point to Robby’s photo and say, “That might be the guy, but I’m not sure.” The police can’t count this as a positive identification; but, based on other evidence, they become convinced that Robby is guilty, so he’s arrested and brought to trial.
During the trial, you’re asked to testify, and when you’re on the stand, the prosecutor asks, “Do you see the perpetrator in the courtroom?” You answer yes, and so the prosecutor asks you to indicate who the robber is. You point to Robby and say, “That’s him-the man at the defense table.”
In-court identifications (I.D’s), like the one just described, are dramatic and are enormously persuasive for juries. But, in truth, in-court I.D’s are problematic for several reasons. First, research tells us that people are often better at realizing that a face is familiar than they are in recalling why the face is familiar. In the case just described, therefore, you might (correctly) realize that Robby’s face is familiar and sensibly conclude that you’ve seen his face before. But then you might make an error about where you’d seen his face before, mistakenly concluding that Robby looks familiar because you saw him during the crime, when in actuality he looks familiar only because you’d seen his picture in the photospread! This error is sometimes referred to as “unconscious transference” because the face is, in your memory, unconsciously “transferred” from one setting to another. (You actually saw him in the photospread, but in your memory you “transfer” him into the original crime- memory’s version of a “cut-and-paste” operation.)
Second, notice that in our hypothetical case you had made a tentative identification from photospread. You had, in effect, made a commitment to a particular selection, and it’s generally difficult to set aside this commitment in order to get a fresh start in a later identification procedure. In this way, your in-court I.D. of Robby is likely to be influenced by your initial selection from the photospread-even if you made your initial selection with little confidence.
Third, in-court identifications are inevitably suggestive. In the courtroom, it’s obvious from the seating arrangement who the defendant is. The witness also knows that the police and prosecution believe the defendant is guilty. These facts, by themselves, put some pressure on the witness to make an identification of the defendant-especially if the defendant looks in any way familiar.
Fourth, the justice system works at a much slower speed than any of us would wish, with the result that trials often take place many months (or years) after a crime. Therefore, there has been ample opportunity for a witness’s memory of the crime to fade. As a result, the witness doesn’t have much of an “internal anchor” (a good and clear memory) to guide the identification, making her or him all the more vulnerable to the effects of suggestion or the effect of the earlier commitment.
In light of these concerns, many researchers would argue that in-court identifications have little value as evidence. In addition, note that some of these concerns also apply to out- of- court identifications. I testified in one trial in which the victim claimed that the defendant looked familiar. and she was almost certain that he was the man who had robbed her. It turned out, though, that the man had an excellent alibi. What was the basis for the victim’s (apparently incorrect) identification? For years, the defendant had, for his morning run, used a jogging path that went right by the victim’s house. It seems likely, therefore, that the defendant looked familiar to the victim because she had seen him during his run-and that she had then unconsciously (and mistakenly) transferred his face into her memory of the crime. It’s crucial that the courts and police investigators do all that they can to avoid these problems. Specifically, if a witness thinks that the defendant “looks familiar,” it’s important to ask whether there might be some basis for the familiarity other than the crime itself. With steps like these, we can use what we know about memory to improve the accuracy of eyewitness identifications-and, in that way, improve the accuracy and the efficiency of the criminal justice system.