Cognitive Daily reports nearly every day on fascinating peer-reviewed developments in cognition from the most respected scientists in the field.
Greta Munger is Associate Professor of Psychology at Davidson College whose works include The History of Psychology: Fundamental Questions. Dave Munger is a writer whose works include Researching Online and The Pocket Reader. And yes, he is married to Greta.
The text below will bring up an animation. Just look at it once -- no cheating! A picture will flash for about a quarter of a second, followed by a color pattern for a quarter second. Then the screen will go blank for about one second, and four objects will appear. Use the poll below to indicate which object (#1, 2, 3, or 4) appeared in the picture.
Over at Uncertain Principles, Chad Orzel's hosting a discussion on who should be on a hypothetical Mount Rushmore of science. There's a fairly broad consensus that Darwin, Einstein, and Newton make the cut, but rather heated debate on who should be the fourth member.
Many of Chad's readers suggest Sigmund Freud. I found that surprising, since the field of psychology has largely moved away from the work of Freud. Freud is still very influential in literary and cultural studies, but not so much in the world of science. Indeed, one of Freud's lasting influences was the attempt to undertake a rational analysis of literature; to analyze the motivations of characters as if they were real people (and vice versa).
Though Freud's analysis of the human mind has little basis in science, scientists do still attempt to understand literature and other forms of art, but their methods have changed considerably. For one thing, researchers acknowledge that "high art" is perhaps too nuanced to withstand scientific analysis, and so have focused on simpler works. Instead of Oedipus Rex, think Moonraker.
What's it like to have all your memories erased? Well, not all your memories, because if that happened, you'd simply be like a newborn infant, and you'd have to relearn everything. The more interesting scenario is to lose only certain memories -- the memories that most people think of as "true" memories: episodic memory.
Memories can be divided into three rough categories: episodic, semantic, and procedural (there are actually many more categories). Procedural memories are the memories of how to do things: driving a car, walking, sewing, and so on. Semantic memories are bits of factual knowledge: names, places, meanings. Episodic memories consist of the explicit recollection of specific events: prom night, my trip to Monument Valley, and so on.
A few nights ago, Greta and I watched the movie Unknown White Male, which purports to be a true case history of a 33-year-old man, Doug Bruce, who suddenly and inexplicably lost his entire episodic memory and much of his semantic memory. In fact, the movie demonstrates the inadequacy of such categories -- what, for example, is the memory of the concept "ocean"? In one sense, it's purely semantic: an ocean is a large body of salt water. But when Bruce visits the ocean for the first time following his amnesia, he is overwhelmed with a vast array of new sensations, from the sound and power of the surf, to the water filtering the soft sand through his feet. This particular ocean visit could become an episodic memory, but isn't there a semantic aspect to the power of the surf? Bruce can't remember whether or not he can swim, but when he dives into the water, he quickly realizes he can stroke effortlessly through the waves. Is all knowledge of swimming procedural, or are there finer points of such knowledge, such as "keep your elbows up" better characterized as semantic?
Last week we discussed two experiments in a report by Adam Anderson about how the phenomenon of attentional blink is modified when the task includes arousing words. Perhaps not surprisingly, we're more likely to notice arousing words like "ejaculate" or "foreplay" in a rapidly presented sequence than neutral words like "plane" or "clock."
But Anderson wasn't finished—he wanted to explain why this phenomenon occurs. Are we more likely to remember arousing words after the fact? Or are arousing words inherently more able to attract our attention? So, Anderson reversed the attentional blink task. As before, participants were shown a rapidly flashed sequence of words, appearing randomly in different colors. The task was to identify two words displayed in different colors from the rest: a first word displayed in white, and a second green word. The white "word" was always a sequence of digits (00000000000, 55555555555), and the second word was a neutral word (mirror, surplus). However, all the other words in the sequence were randomly chosen from either a set of arousing or neutral words. Given this massive distraction, how accurate were participants at identifying the words?
Overall, compared to previous experiments, they were much less accurate—and when the distractors were arousing, performance was consistently worse than for neutral distractors. Given that in both cases, participants are not being asked to remember the arousing words, this result suggests that the diminished attentional blink associated with arousing words is not due to arousing words being more memorable, but because they are more likely to attract our attention in the first place.
But perhaps when we see an arousing word, we direct more attention to it because we exclude other objects from our attention. Seen this way, attention is a matter of different inputs competing for our mind's limited processing resources. Perhaps arousing words are simply those that are better able to use these resources. The other possibility is that attention overall is improved when we are aroused. To try to differentiate between these possibilities, Anderson designed another experiment. As in previous experiments, participants were asked to identify two words, one displayed in white and a second in green, among a rapidly presented list of distractor words in black. This time, participants were encouraged to identify the first word (actually either a sequence of Xs or Os) as rapidly as possible. The second word was either an arousing or a neutral word. The basic results were the same as in other tests: for neutral words, an attentional blink occurred for about 400 milliseconds after the first word, and for arousing words, this blink was diminished. But I want to focus in on another set of results, which compare reaction time for the first word with accuracy on the second word:
Participants who had the fastest reaction times to the first word (in quartile 1) were also the most accurate at identifying the second word. However, when viewing arousing words, accuracy remained relatively high regardless of reaction time. With neutral second words, accuracy diminished as response time increased. This result too suggests that arousing words aren't merely more memorable than neutral words—they're better at attracting our attention in the first place. Even more interesting is how quickly this effect occurs. Anderson switched between arousing and neutral words between each trial of the experiment. So the arousing words aren't simply increasing our overall attentive state, they're intrinsically more noticeable.
If these words increased our overall ability, we should see some increase in attention to non-arousing words. Instead attending to these words appears to be a spur-of-the-moment thing: we notice them when they're there; we don't notice other words under similar circumstances.
What does this suggest about the attention system overall? While it's certainly an indepent system of the mind (we still attend to new things even while doing something else), it's also linked into other systems. Emotion, as shown in Anderson's work, has a critical link to attention. Unraveling how these different systems interact with each other will become a critical part of the study of cognition in the future.
Anderson, A.K. (2005). Affective influences on the attentional dynamics supporting awareness. Journal of Experimental Psychology: General, 134(2), 258-281.
Take a look at these two photographs of my son Jim taken a month or so after he was born (and, as he would be quick to point out, nearly 14 years ago). Which is more memorable?
It may depend on your age. It's natural for your priorities to change as you get older, and so it seems, you may have a different response to pictures depicting emotions. Your kids grow up and leave home, and suddenly Little League and Disney seem less significant. Perhaps fine wine and opera rise up to fill that void. Later still, you begin to think about retirement, and gradually it seems more important to reach out to family and friends. Laura Carstensen was part of a group of researchers who developed a "socioemotional selectivity theory" to explain these changes—they argued that our emotion-related goals increase in importance as we age because we are assessing how much longer we have to live.
As we age, they claim, emotion increasingly becomes the central motivator for a wide sphere of actions, from who we choose to spend time with to how we deal with problems. Perhaps surprisingly, this reorienting of goals around emotions, all motivated by impending death, leads to the result that older adults are better off emotionally than younger people.
Carstensen joined with Martha Mather to expand on these conclusions—they wanted to see if this focus on emotions in older adults also affected cognition, and so they developed a simple reaction-time and memory test. Two groups of people participated in the study: older adults with an average age of 74, and younger adults averaging age 26. They were questioned about their emotional state, and consistent with socioemotional selectivity theory, the younger adults scored significantly lower than older adults on an index of negative emotion.
The participants were shown pairs of photos of 60 different faces. Each pair of photos depicted the same person: one with a neutral expression, and one showing an emotion— happy, sad, or angry. The photos remained on screen for 1 second, then disappeared. In place of one of the photos, a small grey dot appeared, and participants were asked to press a button on the keyboard to indicate where the dot had appeared (left or right).
As you might expect, the younger adults responded much faster than older adults—in about 420 milliseconds compared to 780 for older adults. But when responses to emotional faces were compared to those for neutral faces, another striking difference appeared:
These results were obtained by subtracting the average reaction time for the emotional face from the reaction time for the neutral face in a pair. For younger people, there was no significant difference in reaction times between emotional faces and neutral faces, or even between positive and negative faces. For older people, the emotion difference in the faces caused a comparatively large difference in reaction times. The slowest reaction times were always for negative faces, and the fastest times were for positive faces.
After participants completed the reaction time test, Mather and Carstensen tested memory. They showed viewers a new set of paired photos, each containing one previously-viewed face and one new face. The emotions in these new pairs of photos always matched: the task was to indicate which face they had seen before. Here are the results:
When the emotion for the test pair was happy and the original pair of photos had been happy/neutral, older adults were significantly more likely to correctly recall the old picture than for any other condition. While younger adults were somewhat less likely to remember old negative faces, for the most part the emotion of the faces did not impact their memory for faces.
Mather and Carstensen conclude that these results show not only that subjective attention to emotional issues change as we age, but also the way our basic cognitive processes work when we are confronted with emotional images. Motivated by impending death, emotion affects our life priorities, but these important changes as we age also impact our ability to react to and remember simple images.
Mather, M., & Carstensen, L.L. (2003). Aging and attentional biases for emotional faces. Psychological Science, 14 (5), 409-415.
Do you ever wonder if your mood affects the way you think? I'm not talking about behaving more aggressively when you're angry or more passively when you're sad; I'm talking about the subtler impact on cognitive processing. Some recent research has indicated that we process things differently depending on whether we're in a positive or negative mood. People in good moods tend to make more connections between related items, while people in bad moods generally focus on what's in front of them.
Justin Storbeck and Gerald L. Clore realized that there may be a connection between this research on emotion and other research on false memories (presumably they were in a good mood when they made the connection!). Memory research (as we've discussed here) makes a distinction between item-specific and relational processing in memories, each of which are activated in different circumstances. Isn't it possible, then, that we might remember different things depending on whether we're in a good or bad mood?
One method of studying false memories is to present people with a list of items, all related to a critical word, which is not included in the list. For example, the list might include boat, wind, mast, yaw, boom, and water, but not the critical word sail. Then participants are asked to write down as many of the items as possible which appeared on the list. People are often more likely to list the critical word (the one not on the list) than any of the words they actually saw.
Storbeck and Clore wondered: if we're more likely to see relationships between items when we're in a good mood, then are we more likely to demonstrate false memories, which seem to derive from those same relationsips? They used music to induce positive or negative moods in people, then gave them the false memory test. In a second experiment, they expanded on the basic false memory paradigm by asking participants to not only list words they had seen, but any related words they could think of (they were instructed to place a check mark next to words they hadn't actually seen). Here are the results:
The results were as predicted: people in good moods given the basic test falsely recalled the critical words more often than those in bad moods. When they were allowed to write down related words, people in negative moods still showed a lower incidence of false memory. They also were less likely to write down the critical word as a related word—it indeed appears that they made fewer connections between the related words.
Storbeck and Clore also found that there was no difference between the positive and negative mood groups in true recall—they remembered the words actually appearing on the list with equal accuracy. They argue that this result supports the fuzzy-trace theory of memory, which says that we remember things in two ways—verbatim and gist memory. Normally, we form both types of memories for everything, but negative moods appear to inhibit gist memory, so only verbatim memories are formed.
Storbeck, J., & Clore, G.L. (2005). With sadness comes accuracy, with happiness, false memory. Psychological Science 16(10), 785-791.
The movie, a fictionalization of the lives of the legendary team of Broadway writers Richard Rogers (music) and Lorenz Hart (words), only addresses its titular conflict obliquely. The implicit answer, of course, is that you can't have one without the other.
Or can you? While it's difficult or perhaps impossible to scientifically determine whether words or music is more important in a song, Isabelle Peretz, Monique Radeau, and Martin Arguin may have done the next-best thing: they devised a study to try to determine whether language or music is more memorable.
In their study, Peretz et al. played recorded snippets of 48 familiar French folk songs to native French speakers. The snippets included two different recognizable parts of the songs: the beginning, and some other portion. (A corresponding example in English would be "happy birthday" and "to you.") A preliminary experiment showed that listeners had difficulty identifying the songs from the middle portions, so the order of the snippets was reversed (so, for example, they would play "to you" followed by "happy birthday.") Listeners were instructed to press a button as soon as they recognized the clip.
This experiment is an example of a priming study (we have discussed several of these before). The basic priming effect is simple: when a participant has been primed with a related word, they can complete a memory task more quickly. For example, if your task is to identify proper nouns, then you'll respond more quickly to "The Beatles" if you've seen "The Rolling Stones" first.
What Peretz's team wanted to know was whether music or language primed song recognition best. To do this, they created two versions of each snippet: one where the words of the song were spoken, and the second where the melody was sung—but instead of singing the words, the performer replaced each syllable with the sound "la". The snippets were combined in four different ways: a spoken prime followed by a spoken target (e.g. "to you happy birthday"), a spoken prime followed by a sung target ("to you la la la la"), a sung prime followed by a sung target ("la la la la la la"), and a sung prime followed by a spoken target ("la la happy birthday"). The primes and targets were differentiated by how they were played: primes were played to just one ear of the listeners' headphones, while targets were played in stereo.
Initially, Peretz et al. found that when listeners were primed in the same way they were tested (e.g. singing followed by singing, or speaking followed by speaking), they reacted more quickly. However, a vastly more significant effect was found for language targets: when the target was spoken, listeners recognized the song nearly twice as quickly as when it was sung.
While this may seem to be a clear victory for words over music, the team noted that spoken words tended to take much less time than the equivalent sung melody. Perhaps participants were merely getting their information more quickly.
So the team repeated the experiment, this time using a computer to speed up the singing to match the pace of spoken language without changing its pitch. While sung melodies were recognized more quickly than they had been previously, there was still a substantial advantage for spoken language.
But perhaps this is due to the more expressive nature of spoken language—while a sung note can only vary in pitch, each syllable of language conveys much more information. To compensate for this, the team added white noise to each spoken snippet, then compared the resulting recordings to the sped-up sung melodies until a pilot group recognized both types of recordings equally quickly. Then they repeated the original experiment again. This time, there was no significant difference between the priming effect of lyrics or melody. Words and music appear to contribute equally to the memorability of a song.
Peretz et al. suggest that this equal contribution of words and music to the priming effect may be due to the natural similarities of the rhythm of speech and song. It makes some sense—after all, lyricists select their words for their rhythmic qualities, and composers try to find music that appropriately complements the words. And try to imagine a musical written by just "Rodgers," or only "Hart." It doesn't have the same ring as "Rodgers and Hart," the team behind such unforgettable songs as "The Lady Is a Tramp," "This Can't Be Love," and "Blue Moon."
Peretz, I., Radeau, M., & Arguin, M. (2004). "Two-way interactions between music and language: Evidence from priming recognition of tune and lyrics in familiar songs." Memory & Cognition, 32(1), 142-152.
In face to face conversation, we often look away from the person we're speaking with. Somewhat paradoxically, the closer people sit to their conversation companions, the less often they look at them.
But other factors influence how often we avert our gaze, too. When we are asked personal questions, or difficult questions, or possibly when we are trying to deceive, we look away more often. When we talk with someone via a remote video monitor, we look at them more often than when we engage in the same type of conversation face to face.
So what's the cause of this behavior? Do several different causes lead to looking away, or is the root cause the same for all of them? Perhaps we look away when we are feeling socially challenged. After all, difficult questions, or social intimacy, or the heightened social awareness involved in deceiving others could all lead to the same feeling of being put on the spot.
But another explanation is possible at least some of the time. We get a great deal of information by looking at faces, and this information places a significant load on our cognitive systems. Perhaps, when we're asked a difficult question and need to concentrate, looking away from a face helps us focus on the cognitive demands of the question.
So do we look away because we're self-conscious, or because it helps us concentrate? Gwyneth Doherty-Sneddon and Fiona Phelps devised an experiment to distinguish between these two possibilities. They asked 8-year olds four different types of questions: verbal, arithmetic, episodic memory, and autobiographical memory. Each question was rated by the childrens' teachers as easy, medium, or hard. Half the kids were tested face-to-face, by a questioner sitting across a table from them. The other half were tested via a real-time video link. Their questioner appeared on a video monitor. The children were videotaped as they gave oral responses to the questions. Later the tape was analyzed to determine how often they averted their gaze from the questioner.
Doherty-Sneddon and Phelps expected that the kids using the video monitor would avert their gaze less often. They were interested in a different aspect of the results: whether the kids in each condition would respond differently when more difficult questions were asked. Here are the results (click on the picture for a larger version):
The graphs show the proportion of the time the kids looked away as they responded to the questions. As expected, the kids in the face-to-face condition looked away more of the time than those in the video monitor condition. Otherwise, however, the results were essentially the same—as questions became harder, the children looked away more. Doherty-Sneddon and Phelps argue that if gaze aversion were solely due to self-consciousness, the kids in the face-to-face condition would avert their gaze proportionately longer as the questions became more difficult. Since this was not the case, the reason for looking away is probably simply to reduce the overall cognitive demand and focus on the question.
So it appears that there are at least two reasons we look away from others while we talk to them: because of our self-consciousness or embarrassment at the intimacy of the situation, and because averting our gaze enables us to focus on the ideas behind what we're saying. This is not to say there aren't additional reasons. As Doherty-Sneddon and Phelps point out, there are different expectations in different cultures for how much we should look at each other. However, their work does appear to demonstrate that there is more to gaze aversion than just social nicety.
Doherty-Sneddon, G., & Phelps, F.G. (2005). Gaze aversion: A response to cognitive or social difficulty? Memory & Cognition, 33(4), 727-733.
What does it mean to have a gut feeling that you remember something? You see someone you recognize in a coffee shop. Do you remember her from high school? Or maybe you saw her on television. Could she be the manager of your local bank? Perhaps you don't know her at all ... but you've still got a feeling you do. What's that all about?
One theory of memory proposes that what we remember depends on our expectations. We're less likely to remember our old classmate at the coffee shop than at the high school reunion. At the bank, we might greet the manager by name, but we only get a vague sense of recollection when we see her in the checkout line at the grocery store. So what cues that sense of expectation? If the grocery store pipes in the same music they play at the bank, will we remember her then? What if it turns out she's not the bank manager, but another woman about the same height who happens to own the same blazer? Does the music help us notice the difference, or just make us more likely to ask a complete stranger about the status of our mortgage application?
Stephen Goldinger and Whitney Hansen designed a nifty experiment to see how a subtle cue affects memory. They rigged a chair with a set of speakers under the seat: they wanted to generate a subliminal signal—a "buzz" soft enough that most people claim they can't feel it, but loud enough that people can guess that a sound might have been played. In a preliminary test, they gradually decreased the intensity of the buzz until 75 percent of participants claimed no awareness, but 65 percent still guessed correctly.
Next, they asked a new set of volunteers to memorize 96 words—48 "easy" words that had a clear visual image associated with them (e.g. "snowball"), and 48 "hard" words for abstract concepts (e.g. "movement"). After a short period where they were distracted with an opinion questionnaire, they were tested on their memory. For the test, a word would be presented on-screen, and the respondent indicated whether it was old or new—whether it had appeared in the original list of words or not. Half the time during the testing phase, the subliminal buzz was played, and half the time it was not. The same test was repeated with photos of objects, and again with faces.
For easy objects, Goldinger and Hansen found no difference between cases when the buzz was played and when it was not. This makes some sense—to take an obvious example, I'd recognize my wife and kids regardless of the context. However, for hard objects, the result was quite different:
The chart on the left compares accurate "hits"—when participants correctly identified "old" items—and "false alarms," when new items were incorrectly identified as old. When the buzz was played, both hits and false alarms went up for hard items. Rather than actually enhancing memory, the buzz just made people more likely to say they'd seen an item before. The participants were also asked to rate their confidence in their answer on a scale of 1 to 7. The buzz increased confidence for false alarms, but decreased confidence for hits.
As a control, Goldinger and Hansen also ran the same experiment, but changed the buzz so that it was clearly audible, telling participants that they'd hear a buzz sometimes but offering no other explanation (this must have led to some interesting conversation among student participants on campus after the experiment was completed). In this case, the buzz had no impact on accuracy, either for hits or false alarms.
Goldinger and Hansen explain the data this way. When we're certain about a memory, we aren't influenced by external cues—subtle or otherwise. But when a memory is less sure, we tend to rely on "gut feelings." Sometimes, however, a gut feeling is nothing more than a barely perceptible stimulus. Our gut can mislead us—and it can also be imitated by a speaker hidden inside our chair, or the caffeine buzz from an extra cup of coffee, or any number of other things.
Goldinger, S. D., & Hansen, W.A. (2005). Remembering by the seat of your pants. Psychological Science, 16(7), 525-529.
I had a friend in college who was a baseball genius. He could offer up the career stats of every player in the hall of fame; he knew which teams had won the World Series in each year since its inception—he was a great guy to have on your Trivial Pursuit team; the sports category was a gimme for him.
Whether it's sports, molecular biology, or quilting, everyone seems to know someone who's an expert in their field, who seems to possess an inhuman amount of knowledge about their area of expertise. What makes these individuals so special? Part of this expertise seems to be related to the organizational structure of this knowledge. Chess masters, for example, can memorize the positions of chess pieces if they're in real game positions, but not if they're randomly placed on the board. But even so, there still must be a component of memory responsible for retrieving individual items. Perhaps experts also have superior skills for retrieving particular memories. Take a look at this list of football teams:
St. Louis Rams
Seattle Seahawks
Carolina Panthers
Texas Longhorns
Arizona Cardinals
New York Giants
Minnesota Vikings
New Orleans Saints
San Francisco 49ers
Miami Dolphins
If you don't follow American football and you were given 30 seconds to memorize this list, you might be able to recall three or four of the teams 20 minutes later. However, a football fan would notice that one of the teams was different from the rest: the Texas Longhorns are a college team, and all the others are professional teams. When a team led by James Van Overschelde asked football fans to memorize a similar list, nearly seven out of ten could recall that the Texas Longhorns were on the list two days later.
When a separate group of fans was shown a list of college teams that also included the Texas Longhorns, only about 40 percent of them remembered that the Longhorns were on the list.
But what about a non-football-related task: do football experts perform better on this, or is their advantage lost? The participants were asked to memorize a list of two-digit numbers, along with a single letter, like this:
12
73
84
96
37
G
42
62
18
32
A different group was asked to memorize a separate list of just letters, including the same lone letter from the number list. Take a look at the results:
While football fans were significantly better than non-fans at recalling the Texas Longhorns when they were in a list of pro teams, they weren't any better at remembering a letter from a group of numbers. So why are the football fans better at remembering the one college team from a list of pro teams? Clearly they don't just have better memory overall. And it can't be because they are organizing the teams according to some overriding principle—what's salient about the Longhorns is precisely the feature that they don't share.
Van Overschelde et al. argue that this means that experts have not only superior organization of memory in their field of expertise, but also better memory for individual items in that field.
The Parthenon in Nashville, Tennessee, is a full-scale reconstruction of the rather more famous monument atop the Acropolis in Athens, Greece. We visited it with our daughter Nora a few years back:
As you can see, it's a dramatic building, dominating the landscape of the otherwise ordinary city park in which it sits. So, when we're confronted with such a massive landmark, do we use it to organize the surrounding area as well? Several studies have shown that we do pay attention to the surroundings of objects in order to remember their location. If we memorize the locations of a number of objects in a room, and later are asked to imagine ourselves back in a particular spot in the room, we're more accurate pointing in the direction of one of the objects if it's in front of us, rather than behind. If the room is rectangular, we're more accurate pointing to objects that are oriented in a direction parallel to the walls of the room—even if we memorized the objects when we were facing in an oblique direction.
So both the orientation of the viewer and the surrounding area can impact our memory for object locations. But what about when we're outside? Can features in the landscape similarly influence our memory? A team led by Timothy McNamara conducted a study in Centennial Park where the Nashville Parthenon is located to investigate these issues. Since the Parthenon is such a large, regular object, the team suspected it might influence how people's memory for other objects in the park. Volunteer participants in the experiment were blindfolded and driven to the park. The blindfolds were removed and the participants were led on one of two paths through the park. They were instructed to memorize the location of eight objects along the path. The key to the experiment was the orientation of the paths: one path was aligned with the shape of the Parthenon, but the second one was misaligned—rotated by 45 degrees, so participants were always walking at diagonals compared to the monument. I've created a diagram of the area using a satellite image from Terraserver (that's the Parthenon in the middle of the picture):
Notice that the items the participants memorized were located at the intersections of both of the paths. Participants were told that they were allowed to stop and turn their heads as they walked, but they should keep their bodies facing forward along the path at all times. They were led through the path twice, and by the end of the learning phase, they could recall the order in which they had seen each of the objects.
Next, they returned to the laboratory and were tested on the relative locations of the objects using a series of questions, all in the same format. For example, they might be instructed to "imagine you are standing by the bench and facing the tree. Point to the frame."
The results were as follows:
This chart compares the direction people imagined themselves heading to the errors they made pointing to the locations of other objects. Note that higher values on the chart correspond to less accurate location memory. Participants who followed the misaligned path were nearly always less accurate than those who walked the path aligned with the Parthenon—the only exceptions were facing 45 and 225 degrees, where the results were statistically indistinguishable. Why not in those cases? It may be that participants were using other landmarks to frame their memories—for example, the lake, which cuts at about a 45-degree angle on the lower right of the map.
The participants following the aligned path did the best when their imagined views aligned with both their path of travel and the walls of the Parthenon. There was not a comparable effect for those who followed the misaligned path.
McNamara et al. claim that theirs is the first experiment examining real-world outdoor frames of reference. They argue when a viewer's path is aligned with a landmark, the landmark becomes an important aid to navigation and memory. Even when recalling a view that was directly along their path of travel, the misaligned group was nearly always less accurate than the aligned group. But the wide disparity in accuracy throughout the various viewing angles suggests that many factors are involved. Other landmarks such as the lake probably also influenced the results.
McNamara, T.P., Rump, B., & Werner, S. (2003). Egocentric and geocentric frames of reference in memory of large-scale space. Psychonomic Bulletin and Review, 10(3), 589-595.
It often doesn't take much to make an eyewitness to a crime change her or his story. While Mafia hardball tactics for intimidating witnesses make the headlines, just seeing or hearing a different version of the "facts" can be enough. One key (as we've discussed before) is remembering the context for an event. If we can successfully recall that we personally witnessed one version of the story as it occurred last Thursday, then we're more likely to realize that it's different from the article we read in the newspaper the next day. If we don't recall the context of either the original version or the revised version, our chances for making a mistake increase.
So what's going on in our brain when we remember both the context and the event itself, and what's different when we don't? Yoko Okado and Craig Stark designed a study to examine the problem. They showed participants eight different slide shows telling stories on topics ranging from students talking in the hallway outside of class to the theft of a woman's wallet. Each slide show had 50 pictures and was shown twice. During the second showing, 12 of the pictures were surreptitiously changed in an effort to create false memories. Two days later, participants were tested on their memory for those 12 critical slides.
Sure enough, a significant portion of the time, participants responded with false memories: They believed they had seen the same slide in both presentations (the man stole the wallet and hid behind a tree), when in fact they had seen two different slides (in the first slide show, the man hid behind the door, but in the second show, he hid behind the tree).
This result matched earlier research finding that when people watch a movie and then are presented with a written account that doesn't match the movie, they will often falsely "remember" that the written story agrees with the movie. But Okado and Stark were able to take their research one step further, because their participants had agreed to perform the task while undergoing a constant fMRI, which mapped brain activity in three dimensions as they watched the slide shows.
Other fMRI research had previously revealed that when accurate memories are formed, they correspond to increased activity in particular parts of the brain: the medial temporal lobe and the prefrontal cortex. Okado and Stark's data matched this finding: when participants had accurate memories, these parts of the brain were more active during the first slide show. When they had false memories, these parts of the brain were more active during the second, "false" slide show.
What's more, Okado and Stark observed something else: a trend toward increased activity in other areas of the brain (parts of the hippocampus and parahippocampal cortex) when accurate memories were not being formed. Okado and Stark argue that this activity may be related to the inability to correctly recall the context for an item. Other studies have found that the left parahippocampal cortex is among the regions responsible for recalling the source of a memory. Since the region is less active when the critical second slide is presented during creation of a false memory, participants may not be forming the necessary contextual information they need to recall that the misleading slide was not, in fact, present during the original slide show. Similarly, when true memories were formed—when the misleading picture in second slide show was presented, but the participant still accurately remembered the correct first slide—these areas were again more active, suggesting that people had correctly recalled the context of the misleading second slide.
So apparently one of the key moments in determining whether a memory will be true or false occurs right as that memory is formed. During that critical instant, our entire conception of the past—right or wrong—is shaped.
So what does this say about Mafia "hardball" attempts to influence witnesses? Ironically, they may be doing exactly the wrong thing. If a witness is intimidated by physical force to change her original story, isn't she more likely to remember the context? It might be more effective to use subtler techniques to get witnesses to change their tune.
Okado, Y., & Stark, C.E.L. (2005). Neural activity during encoding predicts false memories created by misinformation. Learning & Memory 12, 3-11.
In every courtroom drama, the most dramatic scene is always when the star witness points her finger at the villain and proclaims that "he did it!" The confidence with which an eyewitness describes the perpetrator of a crime is often the most convincing evidence in a court battle. But how accurate is eyewitness testimony? Do we really remember everything as accurately as we think we do? How important are other influences on eyewitness testimony? And what if the witness is a child?
Carl Martin Allwood has been working on these issues for years. In his most recent article, co-authored with Anna-Carin Jonsson and Par Anders Granhag and published in Applied Cognitive Psychology, he takes on the issue of child testimony.
Their study tried to replicate as closely as possible the manner of a police investigation of a crime. 12-year-olds were shown a video of a kidnapping filmed from a witness's eye perspective. Next they filled out a quick questionnaire about what they had seen—the questions gave only two choices of answers, but were very specific in their requests for details about the kidnappers, the crime scene, and the getaway car.
Two weeks later, participants were presented with two sets of answers to the questionnaire: their own, and either a classmate's or a teacher's. Based on these two sets of answers, the children had to rate the degree of confidence they had in their original responses. In fact, the second answer set was a fake, carefully constructed by the experimenters to agree or disagree with the child's own answers. For every correct response, half of the fake answers agreed and half of them disagreed with the child's answers. The same was done with incorrect responses. The point of this was to see what influence of teachers teachers and peers had on the child's confidence in his or her responses. The two-week delay was deliberately chosen to simulate the often lengthy police crime investigation process.
The students rated their confidence in their own answers on a scale from 50% to 100%. They were instructed that 50% meant they were guessing—they had no idea of the correct response, and that 100% meant that they were absolutely certain. Thus, these ratings correspond to the actual odds of their response being correct.
An analysis of the data revealed that there was no difference between the teacher- and the peer-responses to the student answers—they were equally influenced by both their peers and their teachers. This surprised Allwood and his colleagues, because previous studies had suggested that children were more influenced by adults than their peers. Previous research had been with younger children, however, and as they enter their teen years, the influence of peers does begin to rise.
However, the respondents were significantly influenced by the corroboration of other witnesses. When the teacher or peer response agreed with the child, confidence was much higher than when the responses disagreed. Take a look at this graphical version of the results:
The diagonal black line indicates where confidence ratings would correctly correspond to actual accuracy. Any results above that line represent underconfidence, because confidence ratings are less than the actual accuracy. In this case, nearly all of the ratings reflect overconfidence, with even 100% confidence ratings corresponding to a maximum of less than 70 percent accuracy. More importantly, in cases where the teacher or peer agreed with the child, confidence increased, even though the "disagree" confidence ratings still reflected overconfidence.
The same team conducted a similar study in 2004 on adults, and when they compared those results to these results with children, they found that children were influenced to a greater degree by people who disagreed with them: while both adults and children are overconfident about memories, children become less confident to a greater degree when faced with disagreement than adults do.
To sum up, based on these results, both children and adults are overconfident about nearly all their memories, but children are more likely to change their minds when faced with disagreement.
So what memories can we trust? Clearly this study emphasizes details such as the escape vehicle or the environment around the kidnapping. But would witnesses actually disagree about whether a kidnapping took place, or how many kidnappers were involved? We may have hunches, but this study doesn't tell us the answers. Considerably more work will need to be done to learn exactly how much information is necessary for us to form accurate memories.
Allwood, C. M., Jonsson, A.-C., & Granhag, P. A. (2005). The effects of source and type of feedback on child witnesses' metamemory accuracy. Applied Cognitive Psychology, 19(3), 331-344.
I've created a quick animation of distorted pictures of my son Jim, together with some normal ones. Take a minute or so to watch the animation, then decide if the last picture you're shown looks "normal" to you. Click on the normal (but pre-eyeglasses and braces) photo of Jim below to begin:
I'll let you know whether or not the final picture was distorted in the comments.
A large body of research has found that we perceive faces that are closer to the average as more beautiful than distinctive faces. We've written about one such study here, but even more surprisingly other experiments have found that the pictures rated most beautiful are computer composites of several different faces, a true "average" face. But an average face in Bangkok is different from one in Nairobi, which is again different from the average face in Kansas City. There is no one "average" face—it depends on what faces you're averaging together. Perhaps we actually arrive at a conception of beauty simply by averaging together the faces we see around us—maybe we don't have an innate sense of beauty, but instead learn it from our environment.
That's what the animation of Jim's face above was supposed to do: change your idea of a "normal" face. I made the animation after reading a study by a team led by Gillian Rhodes and published in Psychological Science. I showed you distorted images, but they were distorted only in one direction—they made Jim's face more and more spherical. I could also have distorted them in the opposite direction, making the face more and more bowl-like, but I wanted to affect your concept of normal, so I only showed you different degrees of spherical faces.
In Rhodes et al.'s study, their method was a bit more complex. First they showed participants a set of faces distorted in both directions—spherical and bowl-like—and at different levels of distortion, ranging from 10 to 50 percent. Participants rated each image on a scale of 1 to 7 for both normality and attractiveness. Next, for five minutes they were shown a sequence of images much like the animation of Jim above—this set was only distorted in one direction for each participant. Finally, they were shown the whole range of images once again and asked to rate them. This time, the faces that had been distorted as much as 30 or 40 percent were rated as more attractive than any of the other faces. Here's the graph of normality ratings for a group who had seen the positive (spherical) distortion:
In just five minutes, the perception of attractiveness and normality was changed. Whether the distortion was positive or negative, researchers could easily manipulate participants' perceptions of beauty.
So where is this adaptation made? Is it done by the eyes themselves, or some early level of vision processing like where we process shapes and edges? Or is it a higher cognitive function, like how we distinguish different species of animal or read a book? Rhodes and her colleagues devised a new experiment to help isolate where it's taking place. In this experiment, they rotated faces by 45 degrees, so that you'd have to lean your head on its side to make them look right. They devised an even more dramatic distortion, where the eyes were moved apart or together and the nose appropriately narrowed or widened. For the pre-test, the faces were all rotated in one direction, but for the post-test, they were rotated the opposite direction. The results were the same.
Since rotating an image is a relatively high-level cognitive task, the team reasoned that perception of beauty and normality must be an even higher task, something that takes place after images have been rotated.
What's the use of having our conception of beauty so easily manipulated? Rhodes et al. argue that it's essential for this trait to be easily changed based on circumstances. After all, if we find ourselves among members of a different race, we may still need to decide who will make the best mate. Typically, those closed to the average will be the healthiest members of a group. This research might also explain how styles can change so rapidly. I wince when I see 1980s pictures of myself wearing thin pink ties and white jackets with the collars up. But clearly back then, I wasn't seen by others as particularly abnormal or unattractive—if I had been, I wouldn't have a wife and two kids to show for myself today.
Rhodes, G., Jeffery, L., Watson, T. L., Clifford, C., & Nakayama, K. (2003). Fitting the Mind to the World: Face Adaptation and Attractiveness Aftereffects. Psychological Science, 14(6), 558-566.
We've reported on flashbulb memory before, with the Talarico and Rubin study and the MacKay and Ahmetzanov study. First observed in 1977 by Brown and Kulik, flashbulb memories—memories about shocking events—were supposed to be more vivid and long-lasting than normal memories. Jennifer Talarico and David Rubin seemed to have put a damper on the whole concept of flashbulb memory with their finding that while flashbulb memories are more intense and people are more confident about them, they are no more accurate than normal memories. Donald MacKay and Marat Ahmetzanov, using an experimental test, found that when the memory is directly related to the shocking event itself, it is more likely to be remembered than a normal memory.
In a report published in the journal Memory roughly simultaneously with Talarico and Rubin's Psychological Science article, Susan Hornstein, Alan Brown (a different Brown from the Brown of Brown and Kulik fame), and Neil Mulligan seem to have come to the opposite conclusion from Talarico and Rubin. They quizzed psychology students at Southern Methodist University one week after the death of Princess Diana. When the same students were retested 3 and 18 months later, their memories were just as accurate. Further, more confident students were more accurate in their responses. What's going on here? Can these divergent results be reconciled?
Let's take a closer look at Hornstein, Brown, and Mulligan's study. Like Talarico and Rubin, they tested participants nearly immediately after the shocking event occurred and retested several months later. Unlike Talarico and Rubin, they did not simultaneously ask respondents about a normal memory for comparison.
What they did find is something that Talarico and Rubin did not: a significant correlation between emotion and memory accuracy. Take a look at this chart of accuracy ratings.
Students were asked whether how intense their emotions were on learning of Princess Diana's death. The students with high or medium emotional intensity had significantly more accurate memories of the event than those with low emotional intensity. So why didn't Talarico and Rubin find such a correlation? One possibility is a ceiling effect: surely it's plausible that none (or at least very few) of the respondents at Duke felt a "low" level of emotional intensity when they were surveyed the day after the attacks.
But what about Talarico and Rubin's comparison case? Didn't they also ask respondents about an ordinary event occurring a few days before September 11? Why was no emotional correlation found there? The answer might lie in MacKay and Ahmetzanov's experimental study. They found that emotion increased accuracy only when the details of the shocking memory were directly related to the item being recalled. Perhaps the fact that students took a survey on the day after September 11 gave those "neutral" memories preceding September 11 a significant emotional valence. Remember, only a medium level of emotional activity was necessary for Hornstein et al.'s participants to have more accurate memories. If that was the case, then both the shocking and neutral memories would have been coupled with strong emotion, leading to more accurate memories. Talarico and Rubin would be able to discern no difference between the two.
But it's also possible that something else was going on—the array of emotions and thoughts following a shocking event can be staggeringly comples. These complexities are among the difficulties of studying flashbulb memory. Each "flashbulb" event is different. A UK study of flashbulb memory for Margaret Thatcher's resignation found over 60 percent memory retention, but a similar study for the same event with U.S. participants found only 28 percent retention. It does seem fair to say that under certain circumstances, we are more likely to accurately remember events than in others, but learning exactly what those circumstances are will require a great deal of additional research.
Hornstein, S.L., Brown, A.S., & Mulligan, N.W., (2003). Long-term flashbulb memory for learning of Princess Diana's death. Memory, 11(3), 293-306.
Today's article is one of my all-time favorites. It was originally written by Katherine Kiechel, an undergraduate at Williams College as part of her honors thesis, and could serve as a model for others in its simplicity and ingenuity (the report I'm discussing here was revised and coauthored by her professor, Saul Kassin: "The Social Psychology of False Confessions: Compliance, Internalization, and Confabulation," Psychological Science, 1996). Some empirical work has been done on false confessions, and at least one example of a genuine false confession has been reported: Paul Ingram, who confessed to the satanic slaughter of new-born babies, was later accused by a psychologist of a bogus crime. Though initially he denied it, eventually he "confessed," even fabricating new details about the supposed crime.
There are even manuals which advise police on the best way to extract confessions from suspects, which generally involve some level of deceit on the part of the interrogator. Though confessions extracted using threats or physical violence are typically disallowed by the courts, these milder techniques are generally accepted, and result in conviction and prison time for the accused.
However, Kassin and Kiechel were unaware of any experimental study of false confessions. Indeed, a study of false confessions for criminal behavior would probably be unethical, so they devised a task with significantly smaller stakes.
Participants—psychology majors at Williams College who participated for course credit—were told they were taking part in a study of reaction times. They were tested in groups of two, one of which was a confederate. The confederate read a list of letters to the naive participant, who then typed them into a computer as quickly as possible. Before the experiment began, participants were instructed not to hit the Alt key, as this would cause the computer to crash and data to be lost. Sure enough, about one minute into the experiment, the computer did "crash"—without the participant doing anything wrong—and the distraught experimenter rushed into the room and immediately accused them of hitting the Alt key.
Participants were then asked to sign a confession. If they refused, they were asked again. Sixty-nine percent eventually signed. Finally, when they left the experiment room, a second confederate was sitting in the waiting area, apparently ready to participate in the next session. The experimenter told this confederate she'd have to be rescheduled and left the room. To assess if they actually believed their confession, the second confederate asked the participant what happened. Twenty-eight percent of participants expressed belief in their guilt to this stranger, indicating that they had "pressed the wrong key" or something similar.
Finally, the experimenter brought the participant back to the original room and asked them to re-enact the mishap. This was done to see if people would confabulate, or invent, details supporting their confession. Nine percent of them did.
Kassin and Kiechel varied the conditions of the experiment in four ways. First, they made the reaction time task either slow and relaxed or fast and frenzied by using a metronome to time the letter-reading task (they had established earlier that a pace of 43 letters a minute was easy, but 67 was difficult). Second, they either had the confederate corroborate by falsely saying that she had seen the participant press the Alt key or truthfully say that she did not notice anything. This chart of results shows that these circumstances affect the results significantly:
The difference between having a corroborating witness or not was quite astounding. While 35 percent of those in the slow/no witness condition signed a confession, 100 percent of the fast/witness condition did. Even under the fast/no witness condition, only 12 percent internalized belief in their guilt by admitting it to the second confederate. Most shocking of all is the fact that in the fast/witness condition, 65 percent internalized their guilt, and 35 percent confabulated evidence. Since these are conditions that are quite similar—and possibly less extreme—to those advised in police handbooks for obtaining confessions, the rates of internalization and confabulation are strikingly high.
In a 2004 article in Psychological Science in the Public Interest, Saul Kassin and Gisli Gudjonsson report on follow-up research to the Kassin/Kiechel 1996 study, in which participants were told of punishments for confessing ranging from fines to 10 hours of free labor to repair the error. Despite these negative consequences, the researchers found similar effects. However, another follow-up found a much lower rate of confession when the key was the Esc key, a less plausible key to strike accidently.
If I like what I see, I'll receive 5 more issues (6 in all) for just $19.95. If I'm not completely satisfied, I'll simply write "cancel" on the invoice and owe nothing. The free issue is mine to keep.
Cognitive Daily reports nearly every day on fascinating peer-reviewed developments in cognition from the most respected scientists in the field.
Many of Chad's readers suggest Sigmund Freud. I found that surprising, since the field of psychology has largely moved away from the work of Freud. Freud is still very influential in literary and cultural studies, but not so much in the world of science. Indeed, one of Freud's lasting influences was the attempt to undertake a rational analysis of literature; to analyze the motivations of characters as if they were real people (and vice versa).
What's it like to have all your memories erased? Well, not all your memories, because if that happened, you'd simply be like a newborn infant, and you'd have to relearn everything. The more interesting scenario is to lose only certain memories -- the memories that most people think of as "true" memories: episodic memory.
