s'j'rI;nFr){0Professor Paul Bloom: This class today is about language. And language is, to a large extent, where the action is. The study of human language has been the battleground over different theories of human nature. So, every philosopher or psychologist or humanist or neuroscientist who has ever thought about people has had to make some claim about the nature of language and how it works. I'm including here people like Aristotle and Plato, Hume, Locke, Freud and Skinner. I'm also including modern-day approaches to computational theory, cognitive neuroscience, evolutionary theory and cultural psychology. If you hope to make it with a theory of what people are and how people work, you have to explain and talk about language. In fact, language is sufficiently interesting that, unlike most other things I'll talk about in this class, there is an entire field devoted to its study, the field of linguistics that is entirely devoted to studying the nuances and structures of different languages.心理学空间qb.EzL3b$o6NH$K
D%E7f+LT;Y f0Now, I'll first, before getting into details, make a definitional point. When I'm talking about language I'm meaning systems like English and Dutch and Warlpiri and Italian and Turkish and Urdu and what we've seen and heard right now in class in the demonstration that preceded the formal lecture. [Before class started, Professor Bloom had several bilingual students give demonstrations of non-English speech.] Now, you could use language in a different sense. You could use the term "language" to describe what dogs do, or what chimpanzees do, or birds. You could use language to describe music, talk about the--a musical language or art, or any communicative system, and there's actually nothing wrong with that. There's no rule about how you're supposed to use the word "language." But the problem is if you use the word "language" impossibly, incredibly broadly, then from a scientific point of view it becomes useless to ask interesting questions about it. If language can refer to just about everything from English to traffic signals, then we're not going to be able to find interesting generalizations or do good science about it.心理学空间PYa5A R%pQ
So, what I want to do is, I want to discuss the scientific notion of language, at first restricting myself to systems like English and Dutch and American sign language and Navajo and so on. Once we've made some generalizations about language in this narrow sense, we could then ask, and we will ask, to what extent do other systems such as animal communication systems relate to this narrower definition. So we could ask, in this narrow sense, what properties do languages have and then go on to ask, in a broader sense, what other communicative systems also possess those properties.心理学空间I3D`+ay#{U
9y;w?ssc0Well, some things are obvious about language so here are some; here are the questions we will ask. This will frame our discussion today. We'll first go over some basic facts about language. We'll talk about what languages share, we'll talk about how language develops, and we'll talk about language and communication in nonhumans.心理学空间4ro'{~ XuC
I began this class with a demonstration of--that illustrates two very important facts about language. One is that languages all share some deep and intricate universals. In particular, all languages, at minimum, are powerful enough to convey an abstract notion like this; abstract in the sense that it talks about thoughts and it talks about a proposition and spatial relations in objects. There's no language in the world that you just cannot talk about abstract things with. Every language can do this. But the demonstration [before class] also illustrated another fact about language, which is how different languages are. They sound different. If you know one language, you don't necessarily know another. It's not merely that you can't understand it. It could sound strange or look unusual in the case of a sign language. And so, any adequate theory of language has to allow for both the commonalities and the differences across languages. And this is the puzzle faced by the psychology and cognitive science of language.
Well, let's start with an interesting claim about language made by Charles Darwin. So, Darwin writes, "Man has an instinctive tendency to speak, as we see in the babble of our young children, while no child has an instinctive tendency to bake, brew or write." And what Darwin is claiming here, and it's a controversial and interesting claim, is that language is special in that there's some sort of propensity or capacity or instinct for language unlike the other examples he gives. Not everything comes natural to us but Darwin suggests that language does.心理学空间'}V\u0p!B$@-z/X
3C!T_o4_p$Fb|:a0Well, why should we believe this? Well, there are some basic facts that support Darwin's claim. For one thing, every normal--every human society has language. In the course of traveling, cultures encounter other cultures and they often encounter cultures that are very different from their own. But through the course of human history, nobody has ever encountered another group of humans that did not have a language. Does this show that it's built in? Well, not necessarily. It could be a cultural innovation. It could be, for instance, that language is such a good idea that every culture comes across it and develops it. Just about every culture uses some sort of utensils to eat food with, a knife and a fork, chopsticks, a spoon. This probably is not because use of eating utensils is human nature, but rather, it's because it's just a very useful thing that cultures discover over and over again. Well, we know that this probably is not true with regard to language. And one reason we know this is because of the demonstrated case studies where a language is created within a single generation. And these case studies have happened over history.
The standard example is people involved in the slave trade. The slave trade revolving around tobacco or cotton or coffee or sugar would tend to mix slaves and laborers from different language backgrounds, in part deliberately, so as to avoid the possibility of revolt. What would happen is these people who were enslaved from different cultures would develop a makeshift communication system so they could talk to one another. And this is called a "pidgin," p-i-d-g-i-n, a pidgin. And this pidgin was how they would talk. And this pidgin was not a language. It was strings of words borrowed from the different languages around them and put together in sort of haphazard ways.心理学空间#z1lL"Y@'D8Tb1b)Q"YJ
The question is what happens to the children who are raised in this society. And you might expect it that they would come to speak a pidgin, but they don't. What happens is, in the course of a single generation, they develop their own language. They create a language with rich syntax and morphology and phonology, terms that we'll understand in a few minutes. And this language that they create is called a "creole." And languages that we know now as creoles, the word refers back to their history. That means that they were developed from pidgins. And this is interesting because this suggests that to some extent the ability to use and understand and learn language is part of human nature. It doesn't require an extensive cultural history. Rather, just about any normal child, even when not exposed to a full-fledged language, can create a language.心理学空间:X v X yx0a(e0E i]{
And more recently, there's been case studies of children who acquire sign language. There's a wonderful case in Nicaragua in sign language where they acquire sign language from adults who themselves are not versed in sign language. They're sort of second-language learners struggling along. What you might have expected would be the children would then use whatever system their adults use, but they don't. They "creolized" it. They take this makeshift communication system developed by adults and, again, they turn it into a full-blown language, suggesting that to some extent it's part of our human nature to create languages.心理学空间,n;{f:wA'K-f3Zq
Also, every normal human has language. Not everybody in this room can ride a bicycle. Not everybody in this room can play chess. But everybody possesses at least one language. And everybody started to possess at least one language when they were a child. There are exceptions, but the exceptions come about due to some sort of brain damage. Any neurologically normal human will come to possess a language.
What else do we know? Well, the claim that language is part of human nature is supported by neurological studies, some of which were referred to in the chapters on the brain that you read earlier that talk about dedicated parts of the brain that work for language. And if parts of these brains--if parts--if these parts of the brain are damaged you get language deficits or aphasias where you might lose the ability to understand or create language. More speculatively, there has been some fairly recent work studying the genetic basis of language, looking at the genes that are directly responsible for the capacity to learn and use language. And one bit of evidence that these genes are implicated is that some unfortunate people have point mutations in these genes. And such people are unable to learn and use language.心理学空间k|iwY;L#O
So, in general, there is some support, at least at a very broad level, for the claim that language is in some sense part of human nature. Well, what do we mean by language? What are we talking about when we talk about language? We don't want to restrict ourselves, for instance, to English or French. What do all languages share? Well, all languages are creative and this means a couple of things.心理学空间C7OWX9R#bp
0d3XS[G}zV0One meaning is the meaning emphasized by Rene Descartes. When Rene Descartes argued that we are more than merely machines, his best piece of evidence for him was the human capacity for language. No machine could do this because our capacity for language is unbounded and free. We could say anything we choose to say. We have free will. And in fact, language allows us to produce a virtual infinity of sentences. So, we could create and understand sentences that we never heard before. And there are a lot of sentences. So, if you want to estimate how many grammatical sentences under twenty words in English, the answer is, "a lot." And what this means is that any theory of language use and language comprehension cannot simply appeal to a list. When you understand a sentence I said you have to have the capacity to understand a sentence even if you've never heard it before. And this is because we could effortlessly produce and understand sentences that no human has ever said before on earth.心理学空间sbS*d ba
Would anybody volunteer to say a sentence, non obscene, non derogatory, that has never been spoken before on earth, ever? Here. I'll start. "It's surprisingly easy to get a purple tie on eBay if you don't care much about quality." I could imagine no one else in the world has said this before. "I am upset that one cannot easily download 'Buffy the Vampire Slayer' through iTunes." Now, it's possible somebody said both these sentences before, but you probably have not heard them. But you understand them immediately. So, how do you do it? Well, you have rules in your head. You've learnt what the words mean, but you have abstract and unconscious rules that take these words, figure out the order, and in a fraction of a second, give rise to understanding. And that's the sort of thing linguists study.心理学空间 Ou0~*Z[hG
So, take some standard examples from the linguistic study of English. And bear in mind the rules we're talking about here are not rules you explicitly know. They're automatic rules of the same sort we're going to talk about in the context of visual perception in that they're implicit and unconscious and not accessible to explicit understanding. So for instance, immediately you read "The pig is eager to eat" versus "The pig is easy to eat" and in a fraction of a second you know there's an important difference. "The pig is eager to eat" means the state of affairs that we're talking about is when the pig does the eating. "The pig is easy to eat" is when the pig is being eaten.心理学空间@A I \ Tv
L1V)BA)eU Q0You would see a sentence like "Bill knew that John liked him" and you know, without even knowing how you know, that this could mean that Bill knew that John liked Bill or it could mean that Bill knew that John liked Fred. But it can't mean that Bill knew that John liked John. The natural interpretation, in fact, is that Bill knew that John liked Bill. The two words co-refer. Contrast that with "Bill knew that John liked himself," which only has the meaning Bill knew that John liked John. And this is what linguists do for a living so if you hear me talking about this and say, "I want to spend the next forty years of my life studying that," you should become a linguist. But that's the sort of--those are the sort of phenomena that we're interested in.心理学空间Z Vb!rT0P.|5Pp
U1vo@*p\f0Now, it gets more complicated. Those are examples from syntax, but language has many structures. Language has structures going from the bottom to the top. All languages--All human languages have phonology, which is the system of sounds or signs; morphology, which is the system of words or morphemes, basic units of meaning; and syntax, which refer to rules and principles that put together words and phrases into meaningful utterances. And I want to talk briefly about each of these three parts of language before looking at some other issues. I'm indebted here to Steven Pinker's excellent bookThe Language Instinctwhich provides, I think, a superb discussion of these phenomena. And I'm going to steal some of my examples from Pinker.
So, phonology. Phonology is the system of sounds that languages have. There's a subset. There's a list, a finite list, of possible sounds that language can use. I'm going to put aside for the moment the question of sign languages and how they work. I'm going to talk about them in a little bit. The idea is that English has about forty of these phonemes. So, if you're a native monolingual speaker of English you hear speech and each sound you hear is categorized as falling into one of those forty morphemes--sorry, phonemes. So, for example, English has a phoneme of "lu," "l," and a phoneme of "r." And so, an English speaker can hear the difference between "lip" and "rip" and that corresponds to two different words in English. Other languages don't have that distinction and so those distinctions are very difficult for non-native English speakers to learn.心理学空间~Eo0z i`0{
&pT&b}k7Qj0So, part of what goes on when you learn, is you have to learn the language--the phonemes that your language has. Another part of the problem of learning language is you have to figure out what the boundaries are between the words. You have to use sound signals to figure out the boundaries between the words. Now that--If the only language you've ever heard is English, that's going to seem like a really weird example of a problem because you're listening to me speak and in between each of my words you're hearing a pause. You don't have to be very smart to figure out where one word begins and one word ends. But the pause is a psychological illusion. If you were to just talk into an oscilloscope that measured your sound vibrations, there are no pauses between the words. Rather, the pauses are inserted by your mind as you already know where one word begins and another one ends. And you insert a pause at that point.
You could see this when you hear a language you don't already know. So, for those of you who have never heard French before, when you hear somebody say, "Je ne sais pas" you could say, "Remarkable! French has no pauses between words." And you-- And now a French speaker, of course, hears "Je ne sais pas." For Hebrew, I know one sentence in Hebrew: "Sleecha, eypho ha-sheeruteem" which I think is a request for the bathroom. But if you don't know Hebrew there's no pauses. And the truth is, when you each gave your demonstrations, nobody spoke properly because nobody spoke--Here's the sentence: "Glorp [pause] fendel [pause] smug [pause] wuggle." Rather, you all sounded like, "blublublublublub" without any pauses because I don't know your languages.心理学空间GoP#Y0k5]'m
Fvd$w(z7lO0Children come into the world without knowing any specific language and so they have to learn pauses. They have to learn to interpret sounds in context and sometimes they make mistakes. They get problems of segmentation. And there are some illustrations. You could see their mistakes if they're trying to repeat back something that's already known within a society. So, songs are a good example. These are excerpts from children. [misunderstood lyrics from songs] "I'll never be your pizza burnin'." Anybody know--figure out what that corresponds to?心理学空间} qF'F&I'a
5K3U#QBWH/}4h0Student:[I'll never be your] Beast of burden?心理学空间H9[&G+n3Zj+r"co;` n;C
P KW$^,_ E)rx0Professor Paul Bloom: "Beast of burden." Very good. [reading another misunderstood song lyric off of the slide] "A girl with colitis goes by." Somebody?心理学空间SJ%D*ZRL)y
Student: "A girl with kaleidoscope eyes."
y#T|w?[t0Professor Paul Bloom:"The ants are my friends; they're blowin' in the wind." And [laughter] this is a religious one. "Our father with Bart in heaven; Harold be they name… Lead us not into Penn Station…"
S^Pb3yY @0Now, phonological understanding illustrates all sorts of aspects of language processing and, in fact, of consciousness. Because remember I said that, typically, when you hear a sentence you make--you manufacture in your mind gaps between the words. Typically, when there's something which is unclear you'll fill in the gap and figure out what the word is. And you'll hear it that way. So, the few examples--The best examples, again, are for when it goes wrong.心理学空间D?v"xB2b
So, a classic example is from the song "Super Freak" by Rick James. I got a big lecture about copyright laws and this is going to violate most of them. Rick James is going to be sitting on the--at--staring at the web two years from now saying, "Hey. That's my thing." Okay. So, I want you to listen to this line. I'm sure most of you have heard this before but I want you to listen closely. [music playing] What was that last line? [laughter] "The kind of girl you read about--" Well, it turns out that nobody really knows. And it sounds to many people who do top-down interpretation as--to me as well, that "she's the kind of girl you read about inNewsweekmagazine." But that makes no sense at all given that you don't want to "bring home to Mama." [referring to a song lyric] And she's--and it's not the--and in fact, if you check the notes on the song, she's in fact, "the kind of girl you read about in new wave magazines." Now, when you listen to it then, again, knowing that, you hear it that way. [music playing]
7c!m2u&j7c6wc#~0Now, this top-down--This is known as "top-down" processing. Top-down processing is an example of when you know what something is you hear it that way. And this is extremely useful when it comes to filling in gaps in sounds. In normal conversation, if I'm to say "s-- [coughs] entence" you won't hear that as "s-- [cough] entence." Rather, you hear "sentence." You fill in the gap. This can lead to problems. The problem it's led to in my life revolves around the song "Get Crunk" [laughter] because I've heard "Get Crunk" and my children asked me if I would buy them "Get Crunk" from iTunes. My children are eight and ten. And now "Get Crunk," as I was aware from having heard it before, involves the consistent refrain of "get crunk" extremely bad word, "get crunk" extremely bad word, and so I said "no." And then they said, "Well, there's a clean version of it." So, I downloaded the clean version. Unfortunately, knowing what the clean version--knowing what the word is means to me the clean version is not very clean. Now, I will add, [laughter] before people write letters and stuff, this is the clean version. [The music plays, but even though the expletives are censored out you still perceive them as being there] [laughter] Thank goodness they took away that obscene word. [laughter]
&i4Q@j#?2I*ya7F0Okay. So, top-down processing affects how we hear things, usually, almost always, for the better. And in fact, this is a theme we're going to return to next class when we talk about vision because the same thing is going to happen there. How we see the world is often confusing and befuddled but what we know can clear things up. Same with sound.