Chomsky – the evidence I
In this lecture we look at the evidence from neurology and the study of language disorders (aphasias) to see whether there is any evidence for localization of language skills within the brain. We then look at what has been observed of the behaviours of parents and children during the language acquisition process.
A : Introduction
Last week we saw 3 models of language learning :
Chomsky – LAD – UG
- – the child will create language on the basis of the partial and ungrammatical sentences that she hears. The entourage simply provides minimal conditions of care and protection, but does not have to take any particular notice of the child.
Bruner – every LAD needs his LASS.
- Parents provide clear, predictable repeated situations in which meaning of utterances is clear to the child.
- – no need for LAD – children have capacity to make sense of human interaction – this enables them to understand language.
Does the evidence permit us to favour one or the other of these models?
B : The evidence from neurology:
For an excellent round-up of what is known about the human brain, see William Calvin’s book ‘Conversations with Neil’s Brain The Neural Nature of Thought & Language. A full critique of Chomsky and Pinker’s belief in the special nature of language, written from the point of view of neurological anthropology, can be found in Deacon.
Note: Caution is to be taken with evidence from neurobiology. There is a temptation to use the neuro-sciences to underpin a favoured style of teaching. However, it is not at all clear that we are as yet able to move directly from the way the brain is structured to the way teachers ought to plan their classes. This is not simply because our knowledge of the brain is changing rapidly – for example, a number of pedagogues have referred to the tripartite division of the brain into ‘reptilian’, ‘mammalian’ and ‘human’ layer, and have claimed to found their teaching approach on this division ; not all neurologists would today subscribe to this model. It is also because the classroom cannot be fully understood as a set of neurosystems in an unmediated relationship to each other. The social and historical conditions under which schooling occurs cannot be excluded from the equation.
Chomsky suggests that the UG is innate, and that it is specific. If this were so, we might expect to find that language was linked to specific areas of the human brain1. Let us see if this is the case.
Human beings’ brains are lateralised – that is, the right half of your brain controls the left side of your body, and the left half of the brain controls the right side of your body. But, to a far greater extent than among apes and monkeys, one side of the brain appears to be more powerful than the other – in most human beings, the left hand side is dominant. Why should this be?
To answer this question, we need to go back to the year of 1861. In that year, a patient of the French neurologist,Paul Broca, died. The man was known as ‘Tan’, for he suffered from a condition known as ‘aphasia’, in which the powers of speech are severely curtailed – and the only word he was capable of uttering was ‘tan’. Broca carried out an autopsy upon the patient, and he discovered that there was damage to the brain in the left frontal lobe. Later, another patient with a similar deficiency died. Broca autopsied again, and again he discovered a lesion in the same area of the brain. By 1885, after examining the brains of a number of people suffering from aphasia, Broca felt justified in declaring ‘Nous parlons avec l’hémisphere gauche.
Damage to the area that Broca identified – now known as Broca’s area – produces a very typical form of speech defect.The sufferer appears to lose the ability to construct sentences grammatically. He tries very hard to communicate, and, if the condition is not as extreme as it was in the case of Tan, we may engage in meaningful conversation with him.
Not all aphasias2 are of the same kind, however. In some cases, the patient appears to be fluent – indeed, may be exceptionally fluent – but what he says does not make sense. He loses control of his vocabulary, producing malapropisms, and inventing words that do not exist. Moreover, whereas a patient suffering from Broca’s aphasia is able to understand what is said to him, a patient suffering from the second kind may not understand what others say, and also, may not realise that there is something wrong with their speech. People suffering from this often develop paranoid symptoms. This kind of aphasia is linked to lesions in another part of the left hemisphere of the brain – Wernicke’s area, discovered by Carl Wernicke in 1874.
Does this suggest that Chomsky is correct in believing that there is a specific language mechanism in the brain? To some observers, it does. However, it does need to be pointed out that the picture is much more complex than the original formulation by Chomsky might have lead us to believe. I have described two areas that are important in language processing, but there are also others. It is also the case that some aspects of linguistic behaviour appear to be linked to the right hemisphere – emotional colouring, a sense of humour, and a memory for rhymes and songs amongst them. In one way or another, a normal conversation will involve activation of most of the brain. Moreover, it does not appear to be possible to say that any of these areas are exclusively reserved for language processing.
It is also interesting to note that a patient suffering from Wernicke’s aphasia is very close to Chomskian man – they aregrammatically fluent, but make no sense. Chomsky’s grammatical capacity does indeed appear to be linked to Broca’s area – but whereas someone who has had their vocabulary-finding functions interfered with has great difficulty in communicating, while remaining unaware of those difficulties, someone who has had their grammar removed may still be able to communicate, and is aware of the difficulties from which they suffer. This may be seen as suggesting that Chomsky does overemphasise the importance of syntax.
Now let us look at how children actually do learn language.
They may begin to learn in the womb. We know that they react to their mothers’ voices from birth – they have been listening to her over the last three months of pregnancy. However, the first noticeable active vocal activity begins at about 8 weeks – the baby begins to coo – at first producing individual sounds, but later stringing them together in a rhythmical pattern. Then, at around 20 weeks, the baby diversifies the sounds she is producing, and gradually starts babbling. Babbling involves a selection process.
– in the first stage, the child appears to produce the whole gamut of sounds used by human beings in the production of speech – it is the tower of Babel indeed.
Bit by bit, however, the range of sounds used narrows down, and the child concentrates more and more upon the sounds used by the mother tongue. She is listening to you. So what is being said to her?
We remember that Chomsky claims that children only hear very partial and ungrammatical input. It is now known that this claim is almost certainly false – adults in our culture, when speaking to children, take great care to phrase their utterances correctly. This is probably not because they are thinking primarily about offering the correct syntactic model, but because they are aiming for clarity of expression. It has been noticed that mothers and other caretakers, when speaking to children, adopt a certain number of specific verbal strategies. The style of speech that they use is sometimes referred to as ‘Motherese‘, although non-sexist linguists prefer to call it ‘caretaker talk‘. What are the characteristics of this kind of language?
- 1. Simplified in grammar and meaning
- 2. Shorter sentences – from about 8 words per sentence to four, when speaking to two year olds
- 3. More restricted range of sentence patterns
- 4. Expansion and repetition of sentences
- 5. Slower speech
- 6. Use of special words and sounds
- 7. High pitch
- 8. Large number of questions and utterances with high rising intonation – looking for feedback.
- 9. Embedded in the here and now.
So the language that children hear is by no means necessarily partial and ungrammatical. It has been suggested that these characteristics offer the child such clear samples of language, that there is no need to posit a Chomskian black box, or UG. However, supporters of the UG approach point out that –
- Grammatical forms in caretaker language are not as simple as they may appear.
– large number of Wh- forms.
- Moreover, no-one has yet found a close correlation between language used by caretakers, and language produced by children.
- Not all social groups adapt their speech to young children
In Samoa, for example, adults very rarely speak directly to their children, and among some black communities in the US, it is considered a waste of time to speak to children who are too young to give sensible replies – why talk to them, they don’t know anything yet? And yet, these children also learn language.
- Children do not simply repeat the language they hear from their caretakers
Not only do they fail to copy the utterancesheir mothers give them, tthey also produce utterances that they have never heard, and use structures that they have never heard.
- When mothers interact with their young children, they appear to pay very little attention to the grammatical correctness of their youngsters’ utterances. They correct wrong information, and not wrong grammar. So, Roger Brown reports the following dialogue :
Child : Mamma isn’t boy, he a girl.
Mother : That’s right.
Child : And Walt Disney comes on Tuesday.
Mother : No he does not.
Indeed – and this is of direct interest to language teachers – correction of grammatical form appears to be a waste of time.
The mistakes that the child makes do not appear to be simply random errors. Linguists argue that they are not, in fact , ungrammatical, but that they are based upon the child’s own grammar. Interestingly enough, all children tend to make the same kinds of mistakes at roughly the same period in their linguistic development. For example, English-speaking children working on negation go through a predictable sequence :
- First the negative words ‘No’ and ‘Not‘ appear as single word sentences.
- These combine with other words to form two-word sentences – ‘No car’, ‘Not gone’ etc.
- During third year – negative words used within constructions
You no do that, Mummy
You not got it
while negative auxiliaries also appear. – Won’t, can’t
- Greater accuracy – not replaces no. Double negatives are used for emphasis
- Use of any, hardly, scarcely acquired during early years of school.
As we shall see, there are interesting similarities between this sequence, and the sequence of acquisition of the negation in English by second-language learners.
Followers of Chomsky claim that the regularity of these errors, and the fact that they are not based upon what the child hears, demonstrate that they are derived from the Universal Grammar. The child works through from the simplest possibilities offered by the UG to the more complex, until his own grammar is the same as the grammar of the mother-tongue. The claim is almost that the child does not make mistakes, but simply has a different grammar to the grammar of the adult.
The evidence from neuroscience and from first-language learning is suggestive. We find a number of observations that do fit in with what we would expect if Chomsky were right. However, the evidence needs to be treated with caution.
We have also seen that Chomsky is certainly incorrect in his claim that children do not hear well-formed language. On the other hand, children do seem to understand almost instinctively that language is a rule-bound system, and are capable of discovering the rules underlying their mother tongue with remarkable rapidity. But it needs to be borne in mind that the fact that children seek out the rules underlying language does not mean that they necessarily have a specific approach to language itself. It may simply be a product of the peculiar nature of human intelligence, which makes us look out for and be sensitive to the underlying rules which govern phenomena in the world– this is one of the main characteristics of all human cultural activities, and not just of language-learning.
Next week, we will go on to look at the evidence from observations of language-learning in extreme situations. I will be talking about so-called ‘wild children’, about deaf and dumb children, and about the activities of Nim Chimsky, a close cousin of the famous linguist’s.
1. Chomsky himself does not believe that the LAD can be traced to a specific location in the brain. However, as Steven Pinker puts it, ‘if there is a language instinct, it has to be embodied somewhere in the brain’ (Pinker, op.cit., p. 299).
2. Some discussion of aphasia will be found in most introductory textbooks to psycholinguistics. I have mainly relied on Pinker – particularly pages 299 ff – on Christine Temple, ‘The Brain ; an introduction to the psychology of the human brain and behaviour’, Penguin, 1993, pp. 88-98, and Jean Aitchison, ‘The Articulate Mammal ; An Introduction to Psycholinguistics’, pp. 241 ff.