Professor Paul Bloom: Two follow-ups on yesterday's--I'm sorry, on Monday's lecture. One is that somebody came up after class and asked when the preference for your own language emerges in development and fortunately, [A graduate teaching assistant] studies pretty much exactly this sort of infant understanding. She knew the answer. There's been studies looking at newborn babies finding that pretty much the moment they pop out they favor their own language over other language--over other languages. And this suggests that they are listening while in utero, while in the womb, to the rhythms of their language and developing a preference for it.
cYuZ_3`Nt,L0A second issue is, I talked very briefly about a court case in which the person was--said at a moment where someone else was pointing a gun at a police officer, "Let him have it!" and a police officer was killed. And that person was charged with murder but I admitted I didn't actually know how things turned out and [a graduate teaching assistant] was kind enough to do extensive research. Well, he went to Wikipedia and [laughter] found out the answer. The answer is he was tried and found guilty for murder. He was then subsequently pardoned. In fact, he was pardoned in 1988, which is really nice except he was executed in 1957. But they did it into a movie. So, it's a movie.
;q^ { geP#mp?:wq^ g0Okay. So, I want to do today, for the first part of the lecture, is continue the language lecture and then move to perception, attention, and memory. And what we had spoken about was--We first talked about universals of language, then moved to some detail about the different aspects of language including phonology, morphology, and syntax. We discussed the ways in which language does the amazing things it does, including the fact that language has used arbitrary science or sounds to convey concepts, and that languages exploit a combinatorial system including recursion to put together these symbols into a virtually limitless set of meaningful sentences. We then talked about development and made some remarks about the developmental time course – talking about the emergence of language from babies to – where babies are really good at learning language to you who are not, whose brains have atrophied, whose language capacities are dead.
Final issue is to shift to animals. Now that we know something about language, we could then ask do animals use--possess the same sort of language? And if not, can they learn it? Now, there is absolutely no doubt at all that nonhuman animals possess communication systems. This has been known forever and is not a matter of controversy. And if you want to use the term "language" to mean "communication," then the answer is obviously "yes." Dogs and bees and monkeys have language. If you want to use language though in the more technical, narrow sense as anything that has the properties that we discussed earlier, using English and ASL and Spanish and so on as our background, the answer's almost certainly "no."心理学空间h'T)`oc*Lr
Animal communication systems fall into sort of one of three categories. Either there is a finite list of calls, so vervet monkeys, for instance, have a small list of calls to convey different warnings like "attack from a snake" or "attack from a leopard." There is a continuous analog signal. So, bee dance, for instance, works on this way. Bee dance communicates the location of food sources but doesn't do it in any syntactically structured way. Rather, the intensity of the dance corresponds to the richness of the food source. And then, you get things like random variation on a theme such as birdsong. But what you don't find in any real sense is phonology, morphology, syntax, combinatorial systems or arbitrary names.心理学空间#N2@!b U Ha
\0_ `vzmupN0Now, this much is not particularly controversial. There gets to be a lot of controversy though. This is the summary about nonhuman communication systems. It gets more controversial when we get to famous cases of primates trained by humans such as Kanzi, Nim Chimpsky, and other famous primates that you may well have seen on the Discovery channel and other venues. And this is fairly controversial. If you read the Gray textbook, while nothing in it is particularly inaccurate, I think Gray is actually a little bit too credulous, too believing in the claims that have been made about the abilities of the animals. So many scientists argue, for instance, that animals like Kanzi, even if they can be said to be learning words at all, learn very few of them. And it takes them extensive years of training to learn, unlike a normally developing child who could learn a word in a day or a word in an hour. The utterances often have order but this order tends to be very limited and lacks the recursive properties. And in fact, the lack of recursion is not controversial.心理学空间b W-I J3N;F[G
Finally, the utterances of chimpanzees--trained chimpanzees are extremely repetitive so what you often see on TV and in documentaries is sort of a sampling. And the sampling could often be very impressive but if you take just what they say at random it tends to look like this. This is typical chimpanzee utterances just taken at random: "Nim eat, Nim eat. Drink, eat, me Nim. Me gum, me gum. Tickle me, Nim play. Me eat, me eat. Me banana, you banana, me you give. Banana me, me eat. Give orange, me give, eat orange, me eat orange." Lila Gleitman once commented that if any normally developing child spoke like this, his parents would rush him screaming to a neurologist.
There's a broader question here, which is, "Why would we ever expect a chimpanzee to learn a human language?" We don't normally expect one species to have the capacities associated with another species. So, bats use echolocation to get around and some birds navigate by the stars, but there's not an active research program seeing if cats can use echolocation or dogs could navigate by the stars. And I think one reason why you might be tempted to think, "well, of course chimps must be able to learn language" is because you might be caught in the grips of some bad ideas about language.
(VB!`8D w%|A/j1h;Y0So, one idea is you might say, "Look. Chimps should use language because chimps are so smart." But the response to this is, "they are smart but we know that smart isn't enough." We know that the human capacity for language is not totally a result of smartness. There are smart children who, due to some deficit in their language capacity, don't speak or understand a language. So, the smartness of chimpanzees does not in itself demonstrate that they should be able to learn language.心理学空间O6TE6aK
You might also point out correctly that chimps are our nearest evolutionary relatives, which is right, so you--one would expect on the face of it--it's not unreasonable to expect us to share a lot of abilities with them. On the other hand, we split from them a long time ago and plainly humans are different from chimps. And there was five million years either way and that's more than enough time for a language capacity to evolve.
Now, none of this is to say that the study of nonhuman communication systems isn't interesting. From my own--This is my personal opinion I'll raise here. From my own opinion, the study of the attempts to try to teach chimpanzees, or gibbons, or gorillas, a human language like ASL are misguided. It would be as if a team of monkeys kidnapped a human child and tried to train him how to hoot like a monkey. It might be enjoyable but it does not seem to give us any rich insights. What I think is a lot more interesting is the study of these animal communication systems in the wild. There's a linguistics of human language that has delineated the principles that underlie all human languages. It would be as extraordinarily interesting to attempt the same linguistic program to the other communication systems used in the wild such as the cries of vervet monkeys and bee dance.心理学空间5b4jO$fpV
So, this brings the section on language to a close but I want to tell you a few things we didn't talk about. One of the problems with an Intro Psych course is we have to whip through a lot of topics very fast. So, if you were to take a course that focused directly on language you might learn, for instance, more about language in the brain, something touched about very briefly in the textbook but something that has a large literature associated with it. Similarly, and related to this, there's language disorders, disorders like aphasias and disorders like specific language impairment and dyslexia. There is the study of language perception and production. How is it that we do this amazing feat of understanding and producing words in a fraction of a second? Where does that ability come from?
(a(W~YL:JU2K+k0There is the study of reading which is, in many ways, different from the study of a language. Remember when Darwin described language as an instinct. He carefully distinguished it from other things that don't come natural to us including reading. And in fact, reading is difficult. Reading is a cultural invention, not every human has it. And unlike language, reading is acquired with tremendous difficulty over many years. On the other hand, reading plainly intersects with language. It's a new way of conveying language, moving out from speech to writing. And the psychology and neuroscience of reading is thus very interesting.
YTAZ&f&?rk3|w0There's bilingualism and multilingualism. The questions people in this room typically are going to be interested in is does it matter for how well you learn language whether you're learning one or two or three or four. How is it that a multilingual encodes all these different languages inside a single brain? And so on. Finally, a very hot issue is that of the relationship between language and thought and I'm actually--A few years ago I taught an entire seminar called "Language and Thought" devoted to precisely this question. And it's a cool question and it could break up into two very general questions. One is, "Is language necessary for abstract thought?" And one way to answer that question is to look at creatures without language like babies and chimpanzees and see how smart they are. It might be that they're not--that they're very smart, in which case it would suggest you don't need language for abstract thought. On the other hand, it might be that they have certain cognitive limitations, which would suggest that language is essential for abstract thought.
Then there's the related question. Even once you know a language, does the structural properties of the language that you know affect the way you think? And the claim that the language you know affects how you think is sometimes described as linguistic relativity or the Sapir-Whorf hypothesis. So for instance, there's a lot of research looking at speakers of different languages such as English versus Korean and seeing whether structural differences in these languages affect how you think. Now, some of this work is discussed in the readings, the book--the Gray textbook, and the selections fromThe Norton Anthology.And this makes up--again, I've showed this to you on Monday--your reading response where you have to address this question and take your best shot at answering it. What are your questions about language? Yes.心理学空间/^-y7i [ez7h3t%P
r LLpsa%})wd8g\0Student:[inaudible]
^({a i@TX&s'Y0Professor Paul Bloom:The question was raised, "Some people learn languages easier than others and how do we explain this?" And the answer is you could ask the question both with regard to first language learning – so some children learn language very quickly, some are very slow – and also with regard to second language learning. Some of you are breezing through your second language requirement here at Yale. Others are struggling and miserable. And there's considerable variation. There's the story of Einstein who was very slow to learn language and didn't speak at all until he was four. And in fact, he was a--He said his first words when all of a sudden he was having supper with his parents and he put down the spoon and he said, "The soup is too hot." And his parents stared in astonishment and said, "You've never spoken before." And he said, "Well, up to now everything's been fine." [laughter] It's not a true story. [laughter]
The question of why and where these differences come from, nobody really knows and it's surprisingly hard. There's a slight advantage for being female. Girls are slightly more advanced in language than boys but it's not a big one and you need a hundred people to just see it statistically. There's a big genetic factor. If your parents learned language quickly and learned other languages quickly, you are more likely to. But an understanding of the brain bases of these differences or the cognitive bases or the social bases is just--is largely an open question. Yes.心理学空间J]$v:`wl!K Lg
Student:What happens when parents [inaudible]心理学空间} Dp;msp&W'He
pr1p1O6ABC#\0Professor Paul Bloom:This is actually more the norm around the world than the situation in the United States where kids are exposed to a single language. What happens is children learn both languages. Children are very good, as adults are, of distinguishing different languages on the basis of their sound system and their rhythms so they don't typically confuse them. And then they just learn more than one language. And that's actually more the average state of affairs around the world. Yes.
v1u:fiYg%WJ E8L)Lm0Student:You said that people who are right-handed learn languages [inaudible]心理学空间3q^qs%P3cA+qP.H
VZ^*Vg)J@0Professor Paul Bloom:The question is about the hemispheric specialization for language. And I don't have actually much more to say than what I said before, which I agree is deeply unsatisfying. If you're right-handed, language is probably in the left side of your brain. How many people here are left-handed? For you we don't know. It varies. Some of you have it in the left side. Some of you have it in the right side. For some of you it's kind of diffuse. Now, why is this? And in fact, why are some people right-handed and others left-handed in the first place? Those are really good questions. Yes.
q-Fw)^&K0Student:[inaudible]
r!~P~a%wxS n0Professor Paul Bloom:Yes. I'll--Yes, that's--I'll answer that question. And unfortunately, it's going to be the last one and then I'll go to vision. The question is, "Does learning more than one language cause you to learn them slower than just learning one language?" And it would stand to reason that it would. There's a finite amount of mental resources. If I'm just learning English, I use all of it for English. And if I'm learning English and Spanish I kind of got to split. And you'd expect them to be each learned slower. It's one of the surprises of the study of language development that that common-sense view does not appear to be true. Children learning more than one language seem to show no deficit relative--in each of their languages, relative to a child learning just one language. In other words, if I am just learning English and I'm a kid and you're learning English and Spanish and you're a kid, you'll reach the milestones in English the same time I will. Your extra learning of Spanish doesn't seem to affect you. There doesn't seem to be any detriment for learning multiple languages.心理学空间?6Z6~#Sy\)D
Another question which comes up is, "Is there any cognitive deficit?" In other words, some people have argued that learning multiple languages sometimes harms children in certain ways. This is a claim that's been made in Quebec, for instance, over the debate over how children should be taught English and French. It does not appear to be the case. There appears to be, as far as we know, no down side to learning many languages when you're young. Does that answer your question?心理学空间4N$qPj|:F
N9l Xo8v0I want to move now to the topic that will take us through today and through the beginning of next week – perception, attention, and memory. And I'm putting them together instead of treating them as separate lectures because there's a sense in which they're the same story. You see a scene. You see this scene and you're looking at it and you're perceiving it. It's coming through your eyes and you're interpreting it and you see something. You see a man and you see a house. If you were to shut your eyes, you could still hold that scene in memory. And a week later, if I'm to ask you about that, "What season was it?" you would do pretty well. This is the story I want to talk about – how we do this.
4T'i`ESq8F(XC'P0And in the course of this I want to make a series of claims that go something like this. For perception, I want to first persuade you the problem of perception's hard and that successful perception involves educated and unconscious guesses about the world. For attention, I want to suggest that we attend to some things and not others and we miss a surprising amount of what happens in the world. For memory, there are many types of memory. The key to memory is organization and understanding. And you can't trust some of your memories.心理学空间,H`3c h/Ah5w1hdP/v
{p"e k,\uQ0How many of you remember where you were at 9/11? Many of you are wrong. And I am never going to persuade you of this because you have certain memories. And you could tell the story. Everybody could tell the story where they were when the towers went down. But clever psychologists on September 12 said, "Let's do a study." And they asked people, "Where were you yesterday when you heard the news?" And they told them. And then they went back to them later, a year later, two years later, and said, "Tell me about what happened September 11." And they said, "I remember totally where I was. I have a very--" And then--And often the story was wrong. There is a lot like that which we're going to talk about. And the biggest moral then--so, I put it really, in really big print--We are often wrong about our experiences, both of the present and of right now. So, let's start with perception.心理学空间IV,q+V OPy
1p/hV%V/D2x@b9@B\0There is a story--I went to graduate school at MIT and there was a story there about Marvin Minsky who is the A.I. [artificial intelligence] guru. He--If you've heard the words--the phrase "artificial intelligence," that was him. And if you heard the claim that people are nothing more than machines made of meat--also him. Well, there's a story where he was doing work on robotics and he was interested in building a robot that could do all sorts of cool things that's like a robot. And the story goes the robot had to among--had to write--had to see the world. It had to be able to pick up things and recognize people and see chairs and navigate its way and Minsky said, "That's a tough problem. It's going to take a graduate student a whole summer to figure it out." And he assigned it to a graduate student for a summer project.
n(v;MRgNEo0Visual psychologists, perception psychologists, love that story because the study of computer vision and robotics vision and the attempts to make machines that can identify and recognize objects has been a profound failure. There is, at this point, no machine on earth that could recognize people and objects and things at the level of a really dumb one-year-old. And the reason why is that it's a much harder problem than anybody could have expected. Well, what makes it such a hard problem?心理学空间V nm{1DqR['k/N
h.T6kRd8o2?_d0Well, one reason why you might think it's an easy problem is you say, "Okay. We have to figure out the problem of how people see. Well, here's what we do." [pointing to a slide that caricatures the inside of a person's head as containing a little man, the real "you," sitting in a control room watching a television monitor that is connected to the larger-head's eyeballs] You're in--You're over there and here's your eye. And somehow it has to get to this television monitor and then you look at it and that'll solve the problem of how you see. So, sometimes people say, "Hey. I hear the eye flips things upside down. I guess this guy [the guy in your head] is going to have to get used to looking at things upside down. That's an interesting problem." No. That's not the way to look at it because that doesn't answer any questions. That just pushes the question back. Fine. How does "he" see? We're not answering anything.
Similarly, although the Terminator's [the cyborg assassin from the movie "The Terminator"] view of the world may correspond to that [showing a slide of what vision looks like to the Terminator – a series of gauges and numbers], that doesn't solve any problem of how he actually sees. So, he has all these numbers shooting out there. Well, he has to read the numbers. He has to see this. This [pointing to some icons at the edge of his slide] is my iTunes. [laughter] That's inadvertent.心理学空间7M{WY0g gX
]s4k1f'b,^Q0Here's the right way to think about perception. You got the eye, which is very ugly and bloody, and then around here you have the retina. And the retina is a bunch of nerve cells. And the nerve cells fire at--for some stimulus and not others. And from this array of firings, "firing… not firing… firing… not firing," you have to figure out what the world is. So, a better view is like this. The firings of the neurons could be viewed as an array of numbers. You have to figure out how to get from the numbers to objects and people, and to actions and events. And that's the problem. It's made particularly a difficult problem because the retina is a two-dimensional surface and you have to infer a 3D world from a two-dimensional surface. And this is, from a mathematical point of view, impossible. And what this means is that there--For any two-dimensional image there is an indefinite number of three-dimensional images that correspond to it.心理学空间F3St,f+e[I LZ
:R9Ru:U&^0So for instance, suppose you have this on your retina, an array of light shaped like that [referring to a slide portraying a square and an irregular polygon that could be a square that is tilted backwards in space]. What does that correspond to in the world? Well, it could correspond to a thing just like that that you're looking for or it could correspond to a square that's tilted backwards. And so, you have to figure out which is which. And the way we solve this problem is that we have unconscious assumptions about how the world works. Our minds contain certain assumptions about how things should be that enable us to make educated guesses from the two-dimensional array on to the three-dimensional world.心理学空间.Eu!W7KJ1__4w4bs
N7b@\!AH1W$F0And I purposefully did not make the slides available for this class ahead of time because I don't want people to cheat, but there are several points where you could look at the slides and confirm that some of the things I'm going to tell you are actually true. And I want to give you three examples. One is color. And I'm going to conflate here color and brightness. The other is objects. The other is depth.心理学空间1P z8[ kJ]$h \ A
$y*W%Xt*^0w.C0First, the problem of color. How do you tell a lump of coal from a snowball? Well, that's a lump of coal and that's a snowball, and it's from Google images. How do you know which is which? Well, a lump of coal you say is black and a snowball is white. How do you know? Well, maybe you have on your retina--Your retina responds to sort of color that hits it. It's oversimplified, but let's assume that this is true. So, this is black coming out and that's white and that's how you tell. But in fact, that can't be right. It can't be right because objects' color is not merely a matter of what material they're made of but of the amount of light that hits it. So, as I walk across the stage I fall into shadow and light, and none of you screams out, "Professor Bloom is changing colors!" Rather, you automatically factor out the change in illumination as this is happening.心理学空间psJ"n4Z-F$M
And this could actually be quite striking. So, you see this display over here. Take a look at those two blocks. [a slide portrays two blocks of different luminance, one under a table, one in the middle of a lit room.] I take it you see this one [the object under the table] as lighter than that one. You do. You might imagine this is because this strip [the block under the table] is lighter than this [the block out in the open] but it isn't. They're the same. And you won't believe me until you actually print it out and take a look, but they are in fact the same. I'll show it to you. And you could say I'm tricking you but this is the way it works. There's the close-up. So, remember we're comparing this and this [the two blocks]. Now, let's take away other parts of the environment and you'll see they're the same. [As Professor Bloom covers the background surrounding both of the blocks they suddenly appear to be the same color as one another.]
O'{1G0fMxCE0Now you say, "But hold it. This can't be the same as this" but the answer is--goes like this. We know shadows make surfaces darker. We don't know this like "Here's something I know." Rather, we know this in that it's wired up in our brains. So when we see a surface in shadow we automatically assume that it's lighter than it looks, and we see it as lighter. And you could show this by removing the cues to the shadow. And you see it as it really is. And this is an illustration of how the information to your eyes is just one bit of information; the degree of light coming from a single source is one bit of information that you use to calculate certain assumptions and come to a conclusion.心理学空间Z$cse+MNQ
Here's a different kind of example: Objects. You see this [a picture of a man walking down a path, in front of his house] and you automatically and intuitively segment it into different objects. You segment it into a man and a house and birds and trees. How do you do this? It turns out, to program a computer to segment a scene into different objects is hugely difficult and the question of how we do it is, to some extent, unknown. But one answer to this question is there are certain cues in the environment that are signals that you're dealing with different objects. And these cues are often described as Gestalt principles.