Cognitive Daily reports nearly every day on fascinating peer-reviewed developments in cognition from the most respected scientists in the field.
Greta Munger is Professor of Psychology at Davidson College whose works include The History of Psychology: Fundamental Questions. Dave Munger is co-founder and president of ResearchBlogging.org and a writer whose works include Researching Online. And yes, he is married to Greta.
One of the amazing things about learning language is that children rarely hear language sounds in ideal acoustic environments. Maybe other people are talking in the background, or the dishwasher is running, or the TV is on. Yet somehow children they learn words just the same. By the time we're adults, we've become experts at filtering out irrelevant sounds and patching together meaning out of the cacophony of everyday life.
As one example, listen to this short clip of me saying the word "dinosaur" three times.
I edited the "s" sound out of the first "dinosaur," so you can clearly hear me saying "dino_aur." The last "dinosaur" is obviously complete. But what about the middle "dinosaur," where I edited in a cough/sneeze right over where the "s" sound is supposed to be? Can you still hear the "s" in the background? Let's make this a poll:
Most adults believe they hear the "s" sound in cases like this, even if the sound has been edited out: the perceptual system adds in a sound where it doesn't exist. (Did I edit the sound out here? I'll keep that a mystery for now.) The effect, known as perceptual restoration, has been observed in children as young as five years old.
But what about younger children -- kids who are just beginning to learn language? Do they also exhibit perceptual restoration? It's a difficult question to study, since children who only know a few words aren't able to tell us what they hear with the precision needed (they can't read, so how can they tell us whether they heard an "s" sound?).
The fact that infants are able to learn language without any help from adults can sometimes seem almost miraculous. Not only do children learn to speak and understand language completely on their own, active teaching of language skills seems to make almost no difference in their ability to talk.
One of the first difficulties when learning a language solely from listening to spoken language is determining where one word ends and the next one begins. Native speakers of a language typically leave no audible space between words at all. Even "motherese" doesn't leave any space between words -- if anything the spaces are diminished: "issntdatacutewittlebaby!"
So how do babies learn where one word ends and the next one begins? A group of researchers including Luca Bonatti, Marina Nespor, Jacques Mehler, and Juan Toro, believes it has identified a key pattern that works in a wide range of languages: language learners look to patterns in the consonants for information about where words start and end; they look to vowels to understand the role of words in a sentence. The first part of their explanation was explored in 2005. Their newest paper, led by Toro, considers the second part of the problem. How did they do it? They invented a "language" that had a couple of very simple rules. See if you can figure out the rules by looking at the list of "words" below:
There is a growing body of evidence that very young children -- too young even to talk -- still know plenty of words. When our kids were very young, it was quite clear that they knew the meanings of many more words than they could actually produce. When they couldn't speak at all, they understood words like "Mommy," "bottle," and "diaper." When they were older and could say those words but not complete sentences, they understood more complicated phrases like "go into the kitchen and bring me your sister's sippy cup."
But is there something special about words? Or could babies learn to associate any sound with a meaning? So far the evidence suggests that words are special. Twelve-month-olds, for example, can be trained to recognize words much more quickly than other sounds. But still, this might be due to the fact that these babies have themselves already learned a considerable amount of language. Do younger babies show the same preference for words over other sounds?
Anne Fulkerson and Sandra Waxman enlisted 128 infants -- half of them six months old, and half twelve months old -- and showed them each eight slide-show pictures of either dinosaurs or fish. With each picture, half the babies heard a recording of a woman's voice identifying the picture with a nonsense word, like this: "Look at the toma! Do you see the toma!" The other babies heard a series of tones at a constant pitch for the same duration as the woman's voice. After viewing the series of pictures -- either eight different dinosaurs or eight different fish, they saw one final slide with both a picture of a dinosaur and a fish (neither of which they had seen before).
Psychologists often complain that neuroscientists get a disproportionate share of the glory when the mainstream media reports on their studies. It seems to some that an important new psychology study is often neglected or ignored entirely, while neuroscience studies of similar importance are hailed as "groundbreaking." What is it about pictures of brains that are so appealing?
A while back, were excited to hear of a study which promised to show that people are more impressed by neuroscience explanations of research results than nonneural psychology explanations. Paul Bloom's article about the then-unpublished research suggested that even experts were more impressed with explanations of psychological phenomena that included irrelevant references to brain activity.
But the study was unpublished, so we didn't report on the results here. Now, finally, the study has been published by a team led by Deena Skolnick Weisberg. However, the results, though still intriguing, were a little different from what Bloom's account promised.
The researchers began by asking 81 non-experts to read descriptions of 18 different psychological phenomena like Attentional Blink and the Curse of Knowledge. Then they read an explanation of the phenomenon that either included some bit of neuroscience or did not. Here, for example, are two explanations of why the curse of knowledge occurs:
You might expect someone's cultural background to influence their speech, their appearance, their musical tastes, and the foods they like. You'd probably also expect culture to have an impact on values and beliefs, on stories and traditions. But what about their bodies -- not just physical features like skin color or hair texture, but attitude towards the self? If culture touches on so many aspects of an individual, perhaps it can also impact the subtle ways people think about of their own bodies.
Consider this fairly well-established difference between Euro-Americans and Asian Americans: Euro-Americans tend to believe that they should be concerned primarily with their own self-interest: they should consider their own needs before those of others. Asian Americans tend to believe that they should adapt their actions to the needs of others: they should "harmonize" with those around them. While in some ways this distinction is a stereotype, it has been supported by research -- even if it doesn't apply to every member of each culture.
It's not hard to see how this difference between two cultures might be expressed in Euro-Americans' and Asian Americans' attitudes about their bodies: Euro-Americans might take their own perspective, while Asian Americans might be more likely to take the perspective of others. In English (and many other languages), different language is used depending whose perspective you're taking: From my perspective, you come to my house, but from your perspective, you go to my house.
Angela Leung and Dov Cohen had 131 Euro- and Asian Americans read eight stories sentence by sentence on a computer screen. Half the stories took the perspective of the reader, and half took the perspective of a friend chosen by the reader. Each story had two key sentences involving the "coming/going" (or a similar "taking/bringing") distinction -- an object or person was either depicted as "coming" or "going" towards the protagonist in the story. The researchers measured how long it took readers to read these sentences, and here's what they found:
I don't need words to think about the shape of a car, or how to throw a football, or the taste of a chocolate chip cookie. In fact, things like that are probably easier to think about without using language. That's why the strong form of the Sapir-Whorf hypothesis -- that language is necessary for conscious thought -- doesn't hold up. But even if language isn't required for some domains, it's still possible that it is required for certain types of mental processes. It may even be required for some thoughts that aren't obviously related to language.
Some research suggests that understanding the thoughts of others -- having a theory of mind -- is one such process. Many children who are late in learning language are also late in developing a theory of mind. This story illustrates the classic theory of mind test:
Mouse nibbles cheese.
Mouse puts cheese under box A
Mouse leaves room
Cat enters room, moves cheese from box A to box B, and leaves.
Mouse returns.
Where does Mouse think the cheese is?
Very young children will say box B, because that's where the cheese is now. But at around age 4, they'll correctly answer box A, since Mouse has no way of knowing that Cat moved the cheese. Older children have successfully developed an important aspect of theory of mind -- they understand that Mouse falsely believes the cheese is in box A. But does understanding false beliefs of others require language?
A particular source of dread for politicians is how to respond to negative campaigning or other information impugning their character. By responding, they might only bring attention to an issue that voters hadn't even recognized: "Contrary to my opponent's claims, I have stopped beating my wife, and I haven't consumed more than a fifth of hard liquor in a single sitting."
Worse, many studies have found that even unequivocal denials fail to register in memory. In one study, participants read a report about the possible cause of a fire: a room full of oil paint and pressurized gas cylinders. Later in the report an addendum indicated the room was actually empty, but when questioned, most respondents still believed that the flammable materials in the room had caused the fire.
Clearly there is considerable power in being the first to assert the "truth." But surely people are capable of revising their opinions based on factual evidence. Some of the greatest works of literature in history hinge on readers recognizing that an early impression of a character turned out to be false, from Oedipus learning that he has married his mother to Elizabeth Bennet realizing that Mr. Darcy isn't actually a rat and a scoundrel. If we go on thinking Darcy is proud and prejudiced, we miss the whole point of the novel.
So why is it that sometimes we go on thinking Senator so-and-so is a wife-beater despite his denials but other times we re-evaluate our position based on the evidence? Are we just paying more (or less) attention? David Rapp and Panayiota Kendeou had student volunteers read 24 different "stories" involving a character who demonstrates a trait like sloppiness or laziness, which then may be immediately contradicted in the story. The stories were all just 13 sentences long, and each sentence was displayed one at a time on a computer screen. Here's the beginning of a sample story:
Two facts are true about young children: they sleep a lot more than adults, and they learn language at an astonishing rate. How can they learn so much when they're sleeping so much of the time? Perhaps sleep itself enhances learning. In fact, a number of studies suggest that naps actually enhance learning in adults. What about kids?
A team led by Rebecca Gómez developed a clever test to see if 15-month-olds learn language faster when they've had a nap. At 15 months, most infants understand a lot of language, but don't produce much. But of course, each baby learns at a slightly different rate. How is a researcher to know if the child is learning new words over the course of an experiment, or just reflecting previous knowledge? And if the child can't say much at all, how does the experimenter determine that a word or concept is learned?
The first problem was solved in several previous studies led by Gómez: the researchers used an artificial language -- or rather, just a small portion of a "language." In English we might say "a bird quickly flies," but we'd say "birds quickly fly." The ending of the phrase changes depending on what's said at the beginning of the phrase. The artificial language created an analogous situation:
pel wadim rud vot kicey jic pel puser rud vot fengle jic pel coomo rud vot loga jic pel gople rud vot taspu jic
So phrases starting with pel always end with rud and phrases starting with vot always end with jic, while the nonsense words in the middle of the phrase can change. Can babies learn this pattern? And does napping make a difference?
When you know something, is that different from remembering? Both types of thoughts are clearly part of the memory system, but is there really any difference between the two concepts? We often use the two terms nearly interchangeably: I might say "I remember Suzanne had her purse when we left the restaurant because I saw her pull out her phone at the bus stop," but I might equally say "I know Suzanne had her purse on the bus because she was gabbing on the phone the whole ride home."
But the subtle linguistic difference between the two terms isn't meaningless. We might know George W. Bush is President, but if we remember that James Garfield was the President who preceded Chester A. Arthur, it's likely due to a specific recollection from 11th grade history class (either that or we attended Garfield High School).
We say that we know something because of a general sense that it is true, but we remember something because we recall a particular incident. Psychologists have actually been able to measure the distinction between the two, simply by asking test subjects whether they know or remember the answer to a question (and explaining what they mean by the two terms).
So how does a "know" memory get formed? Are there circumstances when we're more likely to form a "remember" memory? Can one sort of memory transform into the other? Or is the difference between know and remember simply an artifact of the fact that we remember some things better than others? A team led by John Gardiner had volunteers listen to a set of 60 different words, half of them in a male voice and half in a female voice. They rated each word for clarity and pronounceability on a scale of 1 to 5. Then they played a computerized board game for 20 minutes as a distraction. Finally they were tested on which words they remembered.
When we first moved to the small suburban town we still live in, we quickly realized we needed to buy a second car. Nora and Jim were just one and two and a half years old, only barely beginning to understand language. After we made our purchase, sometimes we drove in the old car (a Subaru station wagon), and sometimes in the new car (a Plymouth minivan). Since neither child could pronounce words as complicated as "minivan," they had to come up with their own way to refer to the vehicles. They called the Subaru the "red car" and the van the "blue car."
But there were many other ways they could have referred to each vehicle. They could have said "new car" and "old car," "big car" and "little car," or even just "van" and "car." Why did they refer to them by color?
Most research on young children's word choice in ambiguous situations like this has focused on locating objects. Do you say the car is "on the driveway" or "outside the house"? This doesn't address those other possibilities, such as size, shape, or color. One researcher, Graeme Halford, has speculated that children use the words which require simpler reasoning. "The dog is brown" requires simpler logic than "the dog is bigger than the cat." Even more complex is a statement such as "The chair in the living room is softer than the chair in the dining room." Similarly, while Jim and Nora had both learned colors, they hadn't yet learned how to categorize station wagons and minivans. Any object which transported people around on streets was a "car."
Although this explanation seems reasonable, no one had confirmed it experimentally until Jodie Plumert and Penney Nichols-Whitehead asked 3- and 4-year-olds to hide a tiny toy mouse in a dollhouse while a toy troll hid behind the house. The idea was to find out which words the children used to explain to the troll where to find the mouse. Here's a picture of the house:
There was a lot of buzz online a couple months back when an article entitled "Moniker Maladies" made what seemed to many to be a startlingclaim: Baseball players strike out more often when their names start with "K"; Students with the initials "C" and "D" get worse grades than others.
Actually, this effect, known as the "name-letter effect," has been known for several years. If your name -- even your last name -- starts with T, you're more likely to live in Tacoma or Tulsa than San Francisco or Springfield. Chris at Mixing Memory wrote an excellent summary of the research, so I won't repeat it here.
So if the effect has been around for a while, why publish yet another study rehashing an old concept? Actually the researchers have done more than that. Leif Nelson and Joseph Simmons did pore over baseball record books since 1913 to find their headline-grabbing result (since K is the symbol for a strikeout, players with that initial strike out more often), but one thing they didn't report on is pitchers. Strikeouts are good for pitchers, so shouldn't Sandy Koufax have more than Nolan Ryan? My guess is that they didn't report on this because the results weren't significant. Why weren't they?
The Sapir-Whorf Hypothesis -- stated in its strongest form -- claims that language determines thoughts: if a language doesn't have a means of expressing a particular idea, then people speaking that language can't even conceive of that idea. This strong form has long since been rejected: There are plenty of thoughts we can have without having the words to express them.
But there is also little question that the available words do have an important impact on our thoughts. If a language doesn't have a way to express numbers above 10, for example, then that would probably result in a somewhat different understanding of the world for its speakers compared to speakers of languages with more comprehensive number systems.
It's difficult to demonstrate these kinds of differences in the real world, though. Perhaps the different conception of the world comes more from growing up in a society that doesn't value abstract mathematics than from a particular vocabulary limitation.
Recently researchers have figured out an innovative way around this limitation: They invent entirely new things, and new words to describe them. Take a look at this set of objects, used in a recent study led by Gary Lupyan:
Each object is different, but they all share similar features. We might be tempted to invent just one new word to describe the entire set of objects. Closer inspection reveals that the eight objects on the left share some features which distinguish them from the objects on the right. If we invent one word, "leebish" to categorize the objects on the left, and another, "grecious," to categorize those on the right, will people be better at distinguishing between the two types of objects?
During my brief tenure as a high school teacher, one common suggestion I got from supportive colleagues was to "make your tests teaching tools." "That's often the only time you've really got your students' attention," they suggested, "so don't neglect the opportunity to teach them something."
What they meant is that you shouldn't use misleading or false information in tests as a "trick" to make sure they grasp the material: your test might be the only thing students remember from a unit.
But there's another reason testing is important for learning. For decades researchers have known that more is often learned during testing than traditional "learning." If, for example, students must learn 20 spelling words for a test, in many situations they'll remember the 10 words they were *actually* tested on better than the others.
If I quiz Jim on his Spanish vocabulary words every day, he does better on tests than if he studies on his own. This might be more of a reflection of the quality of his study time than a testing effect, but it still demonstrates the power of testing in aiding learning.
When we are trying to understand what someone is saying, we rely a lot on the movement of their face. We pay attention to how their faces move, and that informs our understanding of what is said. The classic example of this is the McGurk effect, where the same sound accompanied by different facial movements gets interpreted differently.
Take a look at this short video clip (QuickTime required) of me talking, with my voice muffled by what sounds like cocktail party conversation:
Can you understand what I'm saying? What about after I stop moving? Can you understand me in the second part of that clip? Go ahead and replay the video to see if you can hear it the second time through.
That's right, I said two three-word phrases, not just one. If you're like me, you only heard background noise during the second part of the clip. In fact, I'm curious as to whether anyone can understand me at all. Let's make this one a poll:
Children follow a consistent pattern when they acquire language. Instead of learning the most common words first, they start by learning a disproportionate number of nouns. In the youngest talkers nouns form up to 60 percent of their vocabulary, compared to just 40 percent of the vocabulary of a typical 2 and a half year-old (who now knows over 600 words).
This pattern applies in many different languages, even Mandarin and Korean, where verbs appear in more prominent positions in sentences. The phenomenon is so universal that it has led some theorists to speculate that acquisition of non-noun forms is simply beyond the cognitive ability of infants -- they have to "grow into" using verbs. But there's another possible explanation: it could be that anyone learning a language is going to learn nouns first, simply because that's the easiest way to learn language. In this view, the early dominance of nouns has nothing to do with general cognitive ability and everything to do with the process of language learning.
One way to distinguish between the two explanations could be to look at second-language learners. An older child -- or even an adult -- learning a language clearly has the cognitive ability to understand all types of words. But people learning second languages usually learn them differently from infants: they receive formal instruction; they memorize lists of words. Babies are never "taught" language -- they acquire it naturally by watching others speak.
A team led by Jesse Snedeker realized that one population might be able to cast some light on the issue: Children adopted internationally. More than 20,000 kids are adopted in foreign countries and brought to the U.S. each year. If they're adopted before reaching school age, they learn language in the same way as infants: by watching others speak, rather than formal instruction. Snedeker's team located 27 recently adopted children between two and a half to five and a half years old and tested their language abilities every three months until they had been in the U.S. for 18 months.
Imagine that, over the course of a conversation with a friend from work, she makes the following two statements:
It's possible that my brother will be coming into town tomorrow
It's possible that our boss knows about the affair you had with the intern
(You might also have to imagine a more adventurous romantic life for yourself). Which of these two statements do you think your friend believes is most likely to be true? Let's make this a poll:
If I did a good job setting up this scenario, I should be able to predict the results of the poll. I'll get to my prediction in a minute.
First, let's talk a little about why this question is important. The most obvious application of judgments about probability comes from the field of medicine. We've discussed a key problem doctors have in communicating with their patients -- many patients don't understand numerical probability. So if a doctor says, for example, "there's a 1 percent chance you'll go blind from this surgery," many patients will systematically misunderstand what that means.
One possible way to get around this limitation is to use qualitative statements instead of percentages: "it's extremely unlikely that you'll go blind from this surgery." But, as we'll see, there are problems with this approach as well. Jean-François Bonnefon and Gaëlle Villejoubert asked over 800 people from a broad range of backgrounds to imagine two different medical scenarios:
Cognitive Daily reports nearly every day on fascinating peer-reviewed developments in cognition from the most respected scientists in the field.
One of the amazing things about learning language is that children rarely hear language sounds in ideal acoustic environments. Maybe other people are talking in the background, or the dishwasher is running, or the TV is on. Yet somehow children they learn words just the same. By the time we're adults, we've become experts at filtering out irrelevant sounds and patching together meaning out of the cacophony of everyday life.
