1. Language and Cognition Colombo, June 2011
Day 3
Child Language and Disorders

2. Plan Questions of innateness Modelling language processing in children
Acquisition of syntax

3. Why study language development?
Acquisition of a complex cognitive system: understanding how children do this means we are understanding something substantial about how the human mind works
Species-specificity: determining what it is that makes humans unique (if we are unique)
Some children have difficulties acquiring language even in the absence of other apparent learning difficulties
Cultural differences in language use can lead to difficulties in mainstream education
First two points are concerned with lang dev as a basic research topic – understanding it better for its own sake. Lang dev as the “New York City of cognitive science” – it’s so difficult to account for that any inaccurate theory is unlikely to get it right. So if you can come up with a theory to account for lang acq, you can safely assume that it’ll have some utility in other areas of development too.
Second two points are concerned with lang dev as an area of applied research. We want to understand how the system works so we can better develop appropriate means for assessment and intervention.

4. Issues in the study of language development
Nature vs nurture: does the child acquire language from the environment, or is it genetically pre-programmed?
Too simplistic: it’s certainly some combination of these two factors
The debate now is more concerned with the “nature of nature”; what / how much is innately specified, and how much must be acquired

5. Is language innate?

6. Is language innate? Some arguments
no negative evidence
species-specificity
specified neurological and genetic underpinnings
speed of language acquisition: around 2 years for most of the groundwork (cf. shoelace-tying)
critical periods
No negative evidence: parents typically do not correct their children’s grammar; and even if they try to, the child cannot use that information. So how do you ever figure out that some utterance in your language is ungrammatical, if no-one ever tells you so?
Uniformity of grammars: : different speakers of the same language will acquire the same grammar, despite wide variations in ability and experience
speed of language acquisition: it takes most children around 2 years to acquire the grammar and a large proportion of the vocabulary for their language; how could they possibly do this without some built-in information to help them?
language acquisition is error-free: from the very first two-word utterances, children seem to have set some parameters – e.g. Head first in English.
pidgins: a lingua franca which develops when two communities without a common language mix. Pidgins have features of both languages, but not much structure. Children of pidgin speakers get pidgin input (few rules, if any), but they end up speaking a Creole - a structured language like any other.
species-specificity: only humans do this. It makes sense to assume that species-specific abilities are part of the genetic endowment of the particular species. Some have tried to teach language to other species – notably sign language to higher primates – but
. . . it is now widely recognized that these efforts have failed, a fact that will hardly surprise anyone who gives some thought to the matter. The language faculty confers enormous advantages on a species that possesses it. It is hardly likely that some species has this capacity but has never thought to use it until instructed by humans. That is about as likely as the discovery that on some remote island there is a species of bird that is perfectly capable of flight but has never thought to fly until instructed by humans in this skill. (Chomsky 1988, 38).
critical period hypothesis: it is typical of genetically endowed faculties that there is a critical period for their activation. This also seems to be the case for language. Though controversial, it seems that the critical period for language acquisition ends around puberty

7. No negative evidence
Father: where is that big piece of paper I gave you yesterday?
Abe: Remember? I writed on it.
Father: Oh, that’s right. Don’t you have any paper down there buddy?
First example: father responds to content, NOT form – no correction
Second example (family Circus cartoon): a typical response when correction is attempted – the child ignores it

8. Species-Specificity
“. . . it is now widely recognized that these efforts have failed, a fact that will hardly surprise anyone who gives some thought to the matter. The language faculty confers enormous
advantages on a species
that possesses it. It is
hardly likely that some
species has this
capacity but has
never thought to use
it until instructed by
humans. That is
about as likely as
the discovery
that on some
remote island
there is a
species of bird
that is perfectly
capable of flight
but has never
thought to fly until
instructed by
humans in this
skill.”
(Chomsky 1988).

9. Localization of function
Phrenology – Gall, Spurzheim, early 1800s
Different cognitive functions can be localized to different parts of the brain
Level of development of a particular function is reflected in skull formation
The sad tale of Phineas Gage
Dissociation of language from other cognitive faculties
So, let me tell you about how we came to this rather radical standpoint, that language is a separate cognitive system.
GALL, FRANZ JOSEPH ( ), Spurzheim was his colleague – first articulated suggestion that cognitive systems might be different form each other – that different regions of the brain might be responsible for different functions was the treatise on phrenology
Had been recognized earlier by the ancient Egyptians – war wounds etc
Perhaps the most famous TBI patient in the history of medicine was Phineas Gage. In 1848, Gage was a 25-year-old railway construction foreman working on the Rutland and Burlington Railroad in Vermont. In the 19th century, little was understood about the brain and even less was known about how to treat injury to it. Most serious injuries to the brain resulted in death due to bleeding or infection. Gage was working with explosive powder and a packing rod, called a tamping iron, when a spark caused an explosion that propelled the 3-foot long, pointed rod through his head. It penetrated his skull at the top of his head, passed through his brain, and exited the skull by his temple. Amazingly, he survived the accident with the help of physician John Harlow who treated Gage for 73 days. Before the accident Gage was a quiet, mild-mannered man; after his injuries he became an obscene, obstinate, self-absorbed man. He continued to suffer personality and behavioral problems until his death in 1861.

10. Localization Paul Broca (1861): patient ‘Tan’
Slow, effortful, nonfluent speech with many omissions; but good comprehension
on parle avec l’hemisphere gauche
Carl Wernicke: patients with posterior lesions in the left hemisphere
comprehension is impaired but speech is fluent
Broca: on parle avec l'hemisphere gauche
- the brain is organized in such a way that language is supported by one hemisphere
- Broca also noted hemispheric asymmetries in embryos
- he related hemispheric specialization to handedness
- he made remarkable contributions to the concept of localization of function - e.g. using convolutions as landmarks, rather than the phrenology approach of using more absolute landmarks, bony protruberances etc
Language disorder can result from damage to language centers
Broca called such a language disorder APHEMIA - but he was overruled by another French neurologist (Trousseau 1864), and the word APHASIA was adopted instead.
Wernicke: Broca's patient Tan had a lesion in the frontal part of the left hemishere
Wernicke's patients had lesions in other, more posterior areas of the left hemisphere
and they still had language problems - but of a different kind
more double dissociations: language comprehension was not thought to be affected, and speech was severely affected, when the lesion was anterior to the rolandic fissure; but when the lesion was posterior, then language comprehension was severely compromised whilst spoken output of language was relatively spared
Another DOUBLE DISSOCIATION: within language, comprehension and production appear to be different systems, represented in different parts of the brain

11. Genie: The Wild Child

12. Genie: The Wild Child Locked up in a room without language
Discovered at age 13 years
Could she recover language?
Is there a critical period for learning language?
Problems: We don’t know if Genie was generally retarded – as her father had claimed
Curtis makes the point that her non-linguistic IQ advanced every year in step with development, whereas her language did not
Jury is out

13. Special cases

14. Johnson & Newport: Critical Period Effects for L2

15. Cerebral plasticity and language dominance
Damage to language areas in young children may be associated with a shift in language function to the right hemisphere
Plasticity is greater in younger brains – pathways are still being formed – “Equipotentiality” (Lenneberg 1967)
But the LHS seems ‘specialized’ for language – there are usually some functional differences in cases of early childhood hemispheric shifts
Language dominance appears to be established before birth
Planum temporale asymmetries are apparent as early as the third trimester
Early hearing screenings show a right-ear advantage for linguistic stimuli

16. Critical period Evidence from Wild Children
Evidence from L2 acquisition and attainment
Evidence from plasticity
Additional evidence: children who are not exposed to sign language

17. Developmental sequences

18. What we study What’s the nature of the Language Acquisition Device?
How does it interact with environmental and social influences to result in development of language?

19. An example: Stackhouse & Wells (1997)

20. Input
'Physical sound wave' - a sound wave, whether speech or non-speech, occurs in the environment.
'Peripheral auditory processing' - the ear notices that a sound has been heard.
'Speech/non-speech discrimination' - the sound heard is classified as being either speech or a non speech sound.
'Phonological recognition' - speech sounds are classified as being part of a known language. 'Like tuning a radio until you reach a channel where you recognise the language.‘
'Phonetic discrimination' - unusual speech sounds are processed here. This is used when speech sounds differ from the expected 'norm', for example, when processing different accents and dialects.
This system of language processing enables a child to learn and produce new words. No syntax in this model – so the child must also put sequences of words together using synatctic/semantic/pragmatic rules; AND needs to acquire pragmatic knowledge too
Stage 1 - Input processing
To learn to say a word the child must recognise similarities and differences between words; for example, tea/sea are different at the beginning, back/sock are the same at the end, sack/sock differ only by a vowel sound.
To process these similarities and differences the child needs:
good hearing;
attention and listening;
ability to recognise and process sounds.

21. Representation
'Phonological representation' - whole words are stored according to how they sound
'Semantic representation' - the meanings of words are stored here
'Motor program' - the motor instructions required for speech muscles to produce the necessary sounds for words
Stage 2 - Representations (stores)
A word is stored in our memory as a pattern of sounds; this store is structured and organized, each word has its own place.
Sounds simple! But in fact it is very complex; words are grouped according to various psycholinguistic variables – frequency, imageability, AOA; words with the same first sounds
words with the same end sounds
words with the same syllable structure
words that rhyme
words with the same vowel

22. Output
'Motor programming' - allows the production of words not previously known: copying a nonsense word such as 'short'; this enables the learning of new words.
'Motor planning' - allows for factors about how a word will be said, for example, quickly, loudly or with specific intonation.
'Motor execution' - the speech organs are activated and a word is articulated.
Stage 3 - Output processing
The child must activate the movement of the speech organs such as lips, tongue, palate to produce the sounds required to form a word.
The child must plan the movements in the correct sequence and send accurate messages to the muscles.
The muscles and speech organs must then move in the required order to ensure the correct articulation of the word.

23. Questions How do children develop such a system?
How much of this framework do they bring to the language acquisition situation? (i.e., how much is innate?)
How much do they have to learn?
HOW do they learn this?

24. Principles and parameters
Universal Grammar: The innately specified principles and properties that pertain to the grammars of all human languages
Linguistic theory: A hypothesis about Universal Grammar
Principles and Parameters: one such linguistic theory

25. Principles and parameters
Universal Grammar consists of
Principles: accounting for the similarities between languages
E.g. Structure dependency, (extended) projection principle
Parameters: accounting for variation between languages

26. Learnability The Principles and Parameters hypothesis can account for
the specific ways in which (the grammars of) languages can differ and
the speed with which children acquire their language
under this hypothesis, the child only has to choose from among a narrowly restricted set of values in each of a limited number of innate parameters
constrains the hypothesis space
learning a language is reduced to parameter setting and lexical learning

27. Acquisition of negation
Data from English, German & French
Stage 1 (about 24 months): Neg + sentence
No the dollie sleep.
Nein ich putt mache.
No I kaputt make
‘I didn’t break it.’
Pas la poupee dormir.
Not the doll sleep.

28. Acquisition of negation
Stage 2 (about 28 months)
Constructions with negative marker but no auxiliaries
The dollie no sleep.
Ich mache das nich. (adult negation)
I do that not
La poupee dort pas. (adult negation)
the doll sleep not

29. Acquisition of negation
Stage 3 (about 36 months)
Negation with auxiliaries
I didn’t/can’t do it. (adult negation)
Why does it take English children longer to acquire adult-like negation than it takes German or French children?

30. A negation parameter Either: French, German: Any verb OK
Any verb can carry negation, OR
Only auxiliary verbs can carry negation
French, German: Any verb OK
English: only Aux OK
Aux is acquired late (Brown: months)
So in languages where Aux is required to carry negation, adult-like negation forms will also be acquired late

31. Question formation – adult grammar

32. Question formation – adult grammar

33. Question formation – adult grammar

34. Question formation – adult grammar

35. Question formation – adult grammar

36. Acquisition of questions
Stage 1: sentence with external question marker
Mommy eggnog?
Where milk go?
(Boy eat?)
(What boy eat?)
External markers can be either prosodic or wh words

37. Acquisition of questions
Stage 2: Subject-Aux inversion in yes/no questions, but not in wh-questions
Does the kitty stand up?
Oh, did I caught it?
Where the other Joe will drive?
Why kitty can’t stand up?
(What the boy eat?)
(What the boy did eat?)
Oh, did I caught it? – double tense marking – some aspects of the parameter not completely set

38. From Guasti – note variability in amount of SAI
Evidence for a stage in which SAI is present only in one kind of construction and not the other is controversial – it might not be such a clearcut distinction. This distinction is based on Ursula Bellugi’s studies of Adam, Eve & Sarah in the 1960s (her dissertation – 1967)

39. Acquisition of questions
Stage 3: subject-auxiliary inversion in wh questions
What did you doed?
What does whiskey taste like?
(What did the boy eat?)
Ask them what they think is going on in “what did you doed?”

40. Back to the parameter Only aux / any verb can carry negation
Reformulate: distinction between auxiliaries and lexical verbs in terms of their distributional properties
English: yes
French, German: no
In French or German, the lexical verb can be inverted to form a question
Dort la poupee? -- Schläft die Puppe?
*Sleeps the doll?
In French or German, the lexical verb can carry negation
La poupee dort pas -- Die Puppe schläft nicht
*the doll sleeps not
In English, these constructions will not look like the adult equivalents until the auxiliary system is acquired

41. Parameters
So that parameter captures a lot of cross-linguistic variation, as well as some facts about language acquisition
The “verb movement parameter”
Lexical verbs can either move, or they can’t
If they can (French, German), adult-like negation and question formation will be acquired earlier
If they can’t (English), adult-like negation and question formation will not be acquired until the auxiliary system matures

42. Our questions: How do children develop such a system?
Interaction between principles (universals) and parameters (limited variation, determined by exposure to linguistic environment)
How much of this framework do they bring to the language acquisition situation? (i.e., how much is innate?)
The principles are innate; the parameters are present but unset; possibly also some specific statistical learning procedures, an organizational framework, structural properties of the lexicon
How much do they have to learn?
Which way parametric properties go; lexical and phonological properties of the system
HOW do they learn this?
Exposure, statistical algorithms, specific (?) learning mechanisms, domain general (?) learning mechanisms