Exam 2 Flashcards
Subset
A collection of objects that is contained within another set
Infinite sets
They contain an infinite number of items
Ex set of real numbers
Can a subset be infinite?
Yes example within the set of real numbers, the subset of integers is infinite
Can there be a finite subset of an infinite set?
Yes, the numbers 22, 23, 24 of natural number subset are a finite subset
The learning problem
Learning infinite sets from finite subsets is impossible without help. And only a certain type of help is actually helpful
Positive evidence
Is evidence about which items are present in the infinite set
Problem with positive evidence
There is no guarantee that we will get the relevant evidence. It might happen, it might not
Negative evidence
Evidence about which items are absent from the infinite set
Benefit of negative evidence
You can eliminate potential infinite set from consideration. You can test hypotheses and over time you find the right one
Learning language is…
The generalisation from a finite subset to an infinite set
Fact 1 of learning language
All human languages can be characterised as an infinite set of sentences
Fact 2 of learning language
The input children receive when learning language is finite. This has to be true because humans learn language in a finite amount of time
Language
Is an infinite set of sentences
Language input
Is a finite set of sentences that is a subset of the infinite set of the language
Fact 3 of learning languages
All children succeed at language acquisition, except for atypical circumstances (diseases, disorders, imprisonment etc)
Positive evidence for language acquisition
Just another name for input and people to speak to (and around) children
Negative evidence for language acquisition
Some sort of response by the parent after a child produces an ungrammatical sentence but crucially not after a grammatical sentence. Forms of explicit disapproval, non sequiturs, repetitions, recasts, questions
Explicit disapproval
Parent says no or shakes head
Non sequiturs
Parent fails to understand child
Repetitions
Parent repeats the child utterance
Recasts
Parent corrects the child utterance
Questions
Parent asks for more info
What do children do with negative evidence?
They ignore or misinterpret it
Fact 4 of learning language
Negative evidence would guarantee that the infinite set can be learned
Fact 5 of learning language
But children don’t make use of negative evidence
Logical problem of language acquisition
Children are able to learn language despite not having evidence to learn it
Conclusions of the 5 facts
We have a paradox. Children learn an infinite set from a finite set, but don’t use the one method (negative evidence) that would help help
Platos problem
How we humans have so much knowledge when the environment provides is so little evidence to help us build that knowledge
Logical problem of language acquisition/poverty of the stimulus
Highlights the fact that the input (the stimulus) is too poor ( impoverished/poverty) to fully specify the knowledge that we learn
Pure nativism
Nativism solution says that human biology solves the problem. All knowledge is innate (present at birth) and we simply brim out that knowledge out as we grow. First solution proposed by Plato to platos problem
Pure empiricism
Denies that there is a problem. It says that all knowledge comes from experience (or the input). We just have to figure out how that happens. This was most strongly advocated by John lock, an English philosopher
Pure nativism and pure empiricism
Are extreme positions. Nobody in modern age of cognitive science believes these are correct. Instead theories in the middle are explored
Modern nativism
Substantial knowledge comes from biology but experience/input still plays an important role
Modern empiricism
Some knowledge comes from biology bit experience/ input plays the most important role
Noam Chomsky and modern nativism
He’s a modern proponent of a nativist approach to language learning.
Modern nativism more
Substantial innate knowledge
Input/experience still plays a role, but less than the role it plays in empiricism
In short children come to the problem with a lot of genetic help, and then use experience to hone in on the correct answer
Modern empiricism more
Minimal innate knowledge
Input/ experience plays the largest role in learning new
In short children come to the table with the ability from experience and use experience to build up all of the complexity of language
Principles
The fact that all languages share certain properties might indicate that those properties are hard wired in some way
Parameter
If parameters were built in, then the learning problem would be simpler: children just need to figure out the right values
The ability to learn complex rules
Phonology, morphology and syntax all seem to be predicated upon complex rules, suggesting that humans have the ability to learn complex rules
The ability to mean phonemes and morphemes
Our memorisation abilities must be powerful enough to learn the phonemes and morphemes of our languages
Set
A collection of objects
Formants
Highest amplitude peaks in the frequency spectrum created by the human vocal tract
Spectrogram
Frequency is in y axis, time is x axis. So each formant shows up as a horizontal bar
All physical properties are continuous
Means that any physical property of sounds that are critical for speech could potentially take any value along a continuous scale. Formants could show up anywhere along the y axis
Consequence for language acquisition, if the property is continuous
Children need to learn exactly which value is the right value for their language (for speech sound)
Formant values and phonemes
Different phonemes have different formant values
Different people use different values for their formants, for the same vowels!
Different people produce slightly different formants for their vowels
Categorical perception
The act of perceiving physical distinct stimuli as identical for a specific purpose
Example colour is a continuum of wavelengths of light
What are we doing with formants?
Grouping several physically distinct speech sounds into a single category
Children have to learn the categories
Children need to learn the boundaries between vowels to learn their language. They have to figure out where along the continuum to put a barrier.
Is there ever overlap of phonemes?
Yes sometimes but this isn’t a problem for us. We can usually tell which word they are pronouncing
The phoneme learning problem
Formant values like all physical properties are continuous and different individuals create slightly different formant values for the same phoneme. This means children must learn the boundaries between phonemes in the continuum
How children seem to learn 4 steps
- Children appear to be born with the ability to discriminate every sound difference found in human languages. They are universal listeners
- Adults speaking the language around them will tend to produce sounds that are in the middle of language categories. Children are able to notice this.
- Over time children lose the ability to discriminate speech sounds that aren’t in the language being spoken around them. Only in the category boundaries in their language remains
- When this process is finished the children are just like the adults: they can only discriminate between sounds in their language
How long is the process of children learning how to discriminate phonemes
By 10-12 months, they have learned the speech sounds of their language
Language production 6 months
6 months: babbling begins. Tends to be repetitive and does not necessarily correspond to language being spoken by adults
Language production 6-10 months
Over time babbling starts to show variability and slowly takes on more and more characteristics of the language spoken by adults
Language production 10-12 months
The sounds created during babbling only come from the adult language. This is last babbling stage before true words are spoken (around 12 months)
Phonemes nativism v empiricism
Both theories can explain the acquisition of phonemes because both theories allow for innate knowledge (ability to be universal listener) and allow for experience to play a role ( loss of universal listening)
Domain general knowledge
Used by multiple cognitive abilities. If empiricist a require innate knowledge it will be domain general
Domain specific knowledge
Used by one cognitive ability. Nativists allow for innate domain specific knowledge because they don’t mind multiple types of innate knowledge
Timeline of speaking
10-15 months first words are produced
Around 18 months word learning accelerates dramatically, this is the vocabulary explosion
Around 3 years complex morphology appears in words
From 18 month to 3.5 years two word utterances. Function words and longer utterances
Word segmentation problem
There are no obvious breaks in the physical signal that correspond to breaks between words. Children must somehow decide where the breaks between words in the speech stream despite the lack of physical breaks in the stream
Do adults have better processing ability?
No. You have already learned words so you can use this knowledge to help you segment novel speech streams
Transitional probability
The probability of transitioning from one specific sound to the letter that comes after it , kids use this to help segment words
Transitional probability equation for (s j)
of j’s following s’s/# of s’s
How do transitional probabilities help?
The idea is that sounds appear next to each other inside of a word will be more frequent than sounds that don’t appear next to each other in a word
How else might kids segment words? (Still being researched)
- Kids may use transitional probability between phonemes
- Kids may use transitional probabilities between syllables because most low frequency transitions happen across word boundaries
- Children may use the fact that words tend to have one primary stress to help identify separations between words
Is the ability to track transitional probabilities modern nativism or modern empiricism?
Modern empiricism
Is knowledge of syllable boundaries modern empiricism or modern nativism?
Both
Is knowledge that words only have one primary stress modern nativism or modern empiricism ?
Both
Noun bias
The first 50 words of so young children seem to learn tend to be nouns
Why are nouns first?
This is even true for adults. The actors and objects are much easier to figure out (without language) than the actions themselves
Verbs second
When vocabulary explosion hits children begin to learn concrete verbs (thugs they can observe, not abstract verbs like think). Nouns help them learn the verbs
Abstract words third
Abstract nouns and verbs like idea, death, think and die, prepositions and fiction words
Word learning: nativism v empiricism
Empiricism: the ability to identify actors/objects and the ability to identify objects/actors have been identified
Both: the ability to use syntactic frames to learn abstract words
Children and rule learning
There are two changes in mental ability. The change from the first part of the u to the minima and then the change to the second part of the U
Why the two changes with children and rule learning?
No rule just memorisation (all words are exceptions
Rule learned but no exceptions learned
Rule and exceptions learned
What happens at minima?
Children overgeneralise, they apply the rule to words that don’t use it, it takes them time to learn the exceptions
Rule learning nativism v empiricism
Modern empiricism: memorising the (past tense) form of verbs, generalising to a rule
Both: the question is whether there are any aspects of the rule learning that require domain specific knowledge
Transformation
A syntactic rule that takes the output of the phrase structure rule and rearranges (or transforms) that output into a new output
Two steps: phrase structure rules followed by transformations
1) we apply the normal ps rules 2) we apply a transformation that moves is to a new location in the tree
Ex apply ps rules
John is running
Apply transformation
Is John running?
Head movement
Transformation that moves the head from one position to another
Where does head movement seem to occur?
Yes or no questions.
Looking at head movement more deeply, what if there is more than one is?
Need a theory that does not depend on linear order because some sentences move the first and some move the second “is”
Main clause
The highest IP, it is the matrix IP and is the primary IP of the sentence. It forms the structure of the sentence
Embedded IP
Embedded in the matrix of the sentence. It will be lower than the matrix IP. (Embedded clause)
Theory for “is” transformation
The is that can be moved is always the matrix from the matrix IP, not the embedded IP
Structure dependent
The transformation is defined in terms of the hierarchical structure of the sentence, so it is a structure dependent rule
Learning structure dependence
Children need to learn the correct definition of the head movement in order to create English questions
How do children figure out the first head movement theory is incorrect?
They notice questions are formed by moving is
They think that “move first” is the correct theory because it’s simpler
They notice an example is incompatible and switch to the move matrix hypothesis
They need to hear sentences that break the first theory
The learning theory is wrong 3 steps
Children notice questions in English are formed by is
Children don’t make the “move first” hypothesis
Children do not seem to ever hear sentences that “move first” is wrong
Nativist theory on learning
All transformations must be structure dependent
Children notice questions in English are formed by moving is
Because they innately know transformations are all structure dependent, even a sentence is evidence that head movement targets the main clause IS
Therefor as soon as children notice a transformation is necessary they will know the correct definition
Transformation learning nativism v empiricism
Nativism: it could be domain specific and innate. Only attempt structure dependent rules
Empiricism: hypothesising a rule and testing the rule
Stages not ages
A variation in stages at which children hit milestones, children go through the same stages in the same order
Critical period
Where people acquire language. After this is over language acquisition changes. From birth to puberty
Second language acquisition evidence
Steady decrease in success starting just before puberty closed by no effect of age after age 16
Evidence from language deprivation
Individuals tragically deprived of language input
Pidgeons
What happens when large communities of adults who speak different languages are put into close contact
Lexifier
Te language that contributes most of the vocabulary of the pidgin
The grammar of the pidgin
A simplified compromise mix of grammatical properties of the contributing languages
The pidgin shows variation from..
Speaker to speak in terms of both word choice and grammar. Over time it becomes more and more rigid but maintains some amount of individual variation
Are there native speakers of Pidgeons?
No they are only spoken by adults who speak other languages natively. Pidgeons are learned by adults who are too old to learn a new language natively
Are Pidgeons common?
Yes
Creoles
Are what is made when children are exposed to a pidgin during their critical period for language acquisition
Properties of Creoles
Larger vocab
Regulate rules for morphology phonology and syntax
Very little variation between speakers of the creole
Is the native language of the speakers
Creole is a full language, not a sub standard form of English
It is a rule based language that is a full language
Where do the properties of creole grammar come from?
Modern nativism: brought by children. They have substantial knowledge about how language should work. They appear to take a simple and variable pidgin and turn it into a complex full fledged language
Why can only children great a creole?
Related to the fact that adults can’t learn other native languages. They only have their innate language learning mechanisms for a short period after birth
An important double dissociation
Williams syndrome and specific language impairment form a double dissociation between intelligence and language ability. Suggest language ability is independent of general intelligence
Double dissociation
Two abilities can vary independently of each other
Williams syndrome
Cognitive and visual deficits but no language deficit
