advertisement
DESCRIPTION
rttjjTRANSCRIPT
Advertisement
What is psycholinguistics?
The three primary processes investigated in psycholinguistics
•Language Comprehension
•Language Production
•Language Acquisition
Psycholinguistics is a branch of cognitive science
What will be covered in this class?
• How do we produce and recognize speech?
• How do we perceive words, letters, and sentences?
• How do we learn and recall information from texts?
• How can we improve texts to make them easier to understand?
• How does the brain function to process language?
• What are the causes and effects of reading disabilities?
• Is there language in other species?
Central themes in psycholinguistics
1) What knowledge of language is needed for us to use language?
Tacit (implicit) knowledge vs. Explicit knowledge
• tacit: knowledge of how to perform something, but not aware of full rules
• explicit: knowledge of the processes of mechanisms in performing that thing
2) What cognitive processes are involved in the ordinary use of language?
How do we understand a lecture, read a book, hold a conversation?
Cognitive processes: perception, memory, thinking, learning
Some definitions of basic components of language:
Semantics: The meaning of words and sentences
Syntax: The grammatical arrangement of words in a sentence or phrase
Phonology: The sound pattern of language
Pragmatics: How language is used in a social context
Examples from psycholinguistics
Parsing garden path sentences
The novice accepted the deal before he had a chance to check his finances, which put him in a state of conflict when he realized he had a straight flush.
1) The defendant examined by the lawyer turned out to be unreliable
2) The evidence examined by the lawyer turned out to be unreliable
The process of parsing is the process of making decisions
The effect of prior knowledge on comprehension
The procedure is actually quite simple. First you arrange things into different groups. Of course, one pile may be sufficient depending on how much there is to do. If you have to go somewhere else due to lack of facilities, that is the next step; otherwise you are pretty well set. It is important not to overdo things. That is, it is better to do too few things at once than too many. In the short run this may not seem important, but complications can easily arise.
A mistake can be expensive as well. At first the whole procedure will seem complicated. Soon, however, it will become just another facet of life. It is difficult to foresee any end to the necessity for this task in the immediate future, but then one never can tell. After the procedure is completed, one arranges the materials into different groups again. Then they can be put into their appropriate places. Eventually they will be used once more, and the whole cycle will then have to be repeated. However, that is part of life.
Bransford & Johnson, 1973
Recall:
No context: 2.8 idea units out of a maximum of 18
Context afterwards: 2.7 idea units
Context before: 5.8 idea units
Child language development
How many words do you know?
Hint: Dictionary has about: 450,000 entries
Test high school graduates: How many words do they know?
About 45,000 english words
About 60,000 including names and foreign words
The average six year old knows about 13,000 words.
Learning about 10 words per day since age 1. (One every 90 minutes)
How much do we have to teach children to learn language?
Do you have to teach a child to walk?
Is it the same way of learning a language?
My teacher holded the baby rabbits and we patted them
I eated my dinner
A brief history of psycholinguistics
Wilhem Wundt (early 1900s)
Interest in mental processes of language production
• Sentence as the primary unit of language
• Speech production is the transformation of complete thought processes into sequentially organized speech segments.
Behaviorism (1920s-1950s)
• Rejected the focus on mental processes
• Measurement based on objective behavior (primarily in lab animals)
• How does experience (reward and punishment) shape behavior?
B. F. Skinner:
Children learn language through shaping (correction of speech errors)
Associative chain theory:
A sentence consists of a chain of associations between individual words in the sentence
What’s wrong with the behaviorist approach?
Noam Chomsky (1950s - present)
1) Colorless green ideas sleep furiously
2) Furiously sleep ideas green colorless.
3) George picked up the baby
4) George picked the baby up.
Almost every sentence uttered is a new combination of words
The Poverty of stimulus argument:
There is not enough information in the language samples given to children to account for the richnes and complexity of children’s language
The pattern of development is not based on parental speech but on innate language knowledge
Linguistic Diversity vs. Linguistic Universals
Linguistic diversity
There appears to be a lot of diversity among languages
Even within languages there is diversity
When are two languages different?
We speak the same language if we can understand each other
Exceptions: Norwegian and Swedish
Cantonese and Mandarin
Dialects within languages: The myth of pure language
How/why do languages change?
Why does there seem to be a "correct" English?
Members of the dominant (most powerful) sub-culture tend to speak one dialect and may punish those who do not
Linguistic Chauvinism
Belief that one’s own language/dialect is the best of all possible languages
Black English Vernacular (BEV)
Study by William Labov
Interviewed African-American street youth
You know, like some people say if you’re good an’ sh*t, your spirit goin’ t’heaven . . . ‘n if you bad, your spirit goin’ to hell. Well, bullsh*t! Your spirit goin’ to hell anyway, good or bad.
[Why?]
Why? I’ll tell you why. ‘Cause, you see, doesn’ nobody really know that it’s a God, y’know, ‘cause I mean I have seen black gods, white gods, all color gods, and don’t nobody know it’s really a God. An’ when they be sayin’ if you good, you goin’ t’heaven, tha’s bullsh*t, ‘cause you ain’t goin’ to no heaven, ‘cause it ain’t no heaven for you to go to.
• Place holders: "There" vs. "It" in the copula
• Copula: "Is", "Was" optional
• Negatives: "You ain’t goin’ to no heaven"
BEV just as linguistically complex as Standard American English
We don’t see/understand the complexity in other languages
Moral: All languages seem to permit as wide range of expressions as others
Linguistic Universals
What is in common with all languages?
Sentences are built from words based on the same physiological processes
• All languages have words
• All humans have ways of making sounds.
• Languages tend to use a small set of phonemic sounds
• Phoneme: The minimal unit of sound that contributes to meaning
How many phonemes in a language?
• English: 40 phonemes
• Range: Polynesian 11 to Khoisan 141
Discreteness
Messages in human language (e.g. speech sounds) are made up of units of which there is a discrete (limited) number
Arbitrariness
The relationship between meaningful elements in language and their denotation is independent of any physical resemblance between the two.
Words do not have to look or sound like what they describe
Openness
• New linguistic messages are created freely and easily
• Languages are not constrained in a way so that there are a limited number of messages that can be created.
• Linguistic Productivity: The ability to understand and create an unlimited number of sentences
The question studied by psycholinguists is "how to characterize and account for the creativity to construct and create an infinite number of sentences given the limited capabilities of the human brain"
Duality of Patterning
Language involves relating two different kinds of patterns or forms of representation
• A phonological system
• A semantic system
These two systems use very different types of codes, although there is a phonological representation for each item in the semantic system
Phrase structure
Information on how a sentence is grouped into phrases.
The quiet boy ate the red apple
A set of Phrase Structure rules:
PS 1 S (sentence) -------------> NP + VP
PS 2 NP (noun phrase)-------------> det + (adj) + N
PS 3 VP (verb phrase) -------------> V +NP
PS 4 N (noun) -------------> boy, dog, man, book
PS 5 V (verb) -------------> ate, broke, kissed
PS 6 adj (adjective -------------> quiet, red, happy, wormy
PS 7 det (determiner) -------------> a, the
We use "lexical-insertion rules" to put words into the structure.
Phrase-structure rules provide a good account of phrase-structure ambiguity.
They are broiling hens
Morphology
Morphology is the component of grammar that builds words out of units of meaning (morphemes)
A morpheme is the smallest meaningful unit of language
How many morphemes?
bird
firetruck
undereducated
unmicrowaveability
Insights from American Sign Language (ASL)
Unlike speech, signs are expressed in visual or spatial form
Do a lot of the same grammatical concepts hold?
Arbitrariness
ASL possesses iconicity
signs can represent objects or actions to which they refer.
However, the degree of iconicity has declined over the years
Duality of Patterning
signs are composed of smaller elements that are meaningless
Example: 3 parameters
• 19 values of hand configuration
• 12 values of place of articulation
• 24 values of movements
Meaningless patterns can be combined in various ways to from ASL signs.
What about "openness" and "discreteness" within ASL?
Transformational Grammar (Chomsky 1950s)
Language: an infinite set of well-formed sentences
Grammar: A finite set of rules that generates sentences in the language
How do we know that a grammar is a good theory of language?
Three criteria:
Observational Adequacy:
A grammar is observationally adequate if it generates all acceptable sequences and no unacceptable sequences.
Descriptive adequacy:
A grammar must also explain how a sentence relates to other sentences that are similar & opposite in meaning.
The ball was caught by John
John caught the ball
The ball was not caught by John
Explanatory adequacy
It is possible for multiple grammars to attain observational and descriptive adequacy.
Which is the correct/best one?
Children learning language are presented with many samples of language and must determine the grammar from these samples.
There must be some innate language constraints that help children determine the correct grammar.
There exist Linguistic Universals that are common to all languages
The fact that there are similarities in languages is based on the fact that languages are determined by the nature of the mental structures and processes which characterize human beings
A Grammar must explain the role of linguistic universals in language acquisition
Deep and Surface structure
Deep structure: The structure of the sentence that conveys the meaning of the sentence.
Surface Structure: The superficial arrangement of constituents
Deep structure ambiguity: A single surface structure that is based on two different deep structures
Flying planes can be dangerous
Phrase structure rules would not be able to account for the differences in meaning
Sentences can have similar phrase structure, although their underlying structure is different:
John is easy to please
John is eager to please
Sentences can different surface structure, but similar deep structure
Arlene played the tuba
The tuba was played by Arlene
Transformational Grammar
A two part process to derive a sentence
1) Use Phrase-structure rules to generate the underlying tree structure (deep structure)
2) Apply a sequence of transformational rules to the deep structure to generate the surface structure of the sentence
Transformations occur by adding, deleting or moving constituents
John phoned up the woman
John phoned the woman up
Phrase structure approach: Two different rules
VP --> V + (particle) + NP
VP --> V + NP + (particle)
Each sentence is derived separately, using different phrase structure rules.
Transformational grammar approach: One rule
V + particle + NP --> V + NP + particle
John phoned up the interesting woman
John phoned the interesting woman up
John phoned up the woman with the curly hair
John phoned the woman with the curly hair up.
Restrictions on transformations
The particle-movement transformation can not be applied to pronouns
John called them up
*John called up them
Example 2: Passive transformation
NP1 + V + NP2 --> NP2 + be + V + en + by + NP1
Arlene played the tuba
The tuba was played by Arlene
Psychological Reality of Transformational Grammar
If using language is a process of converting the deep structure to the surface structure, then the number of transformation rules applied should affect how long it takes to process a sentence.
However, experiments do not consistently show that this holds true
Current theories of grammar
Lexical-Function Grammar
Made up of three components: a constituent structure, a functional structure, and lexical entries
Constituent Structure: Similar to phrase structure
Functional Structure: All the information needed for semantic interpretation
John told Mary to leave Bill
Predicate tell (subj, obj, V-comp)
Tense Past
Subj John
Obj Mary
V-comp predicate leave
subj Mary
obj Bill
Lexical Entries
Lexical entries contain information about:
• the forms of the word
• the kinds of sentences into which they fit,
• arguments and semantic roles
Mary kissed John
John was kissed by Mary
Entry for "kiss" includes
underlying semantic structure
kiss: (agent, patient)
Forms of the word
kiss: agent = subject: patient = object
(be) kiss: agent=object: patient = subject
Major significance of LFG
Most of the explanation of how we process language is based on the lexicon (where we store information about words) .
Government-Binding Theory or Universal Grammar
Chomsky’s view of innate grammatical mechanisms.
In GB theory, grammar is modular.
Grammar due to interaction of several independent subsystems, or modules.
Each module is fairly simple and performs part of the task
But all modules interact in order to constrain the rules made by the other modules in the grammar
Implications
We all inherit a universal grammar that can be set to different parameter values.
These parameter values correspond to different languages.
As we get experience with a language, we acquire these parameter values, and thus the language upon which it is based.
Research methods in Psycholinguistics
How do we observe, collect information on phenomena related to psycholinguistics?
Naturalistic Observation
Observing information in a non-experimental setting
Slips of the tongue
Phonological switching: Crushing blow --> Blushing crow
semantic replacements: blond eyes for blond hair
Language Acquisition
The use of language over time
Data from naturalistic observation
Rich, but hard to analyze
Controlled experiments
Goal: test an empirical hypothesis
Hypothesis: A chapter will be easier to understand if each section starts with a summary of what will be said.
Independent Variable: Variable that is manipulated to test the hypothesis.
Dependent Variable: Variable representing the behavior we want to measure
Control Variables: Other variables we need to control in order to see the effect of the independent variable
Subjects: Who is going to participate in the experiment?
Analysis: How do we know if there are differences bewteen the two chapters?
The Human Information Processing System
What psychological mechanisms are involved in using language?
The Sensory store
Processes incoming information from the environment
• Individual sensory stores for each sense
• Information retained for a short duration
The visual sensory store
Experiments by Sperling (1960)
X M R K
C N J P
V F L B
The partial report technique
Auditory sensory store
Experiment by Darwin, Turvey & Crowder (1972)
3 digits or letters auditorally presented to each ear and center at the same time
What is the use of the sensory store?
It maintains information long enough so that we can do additional processing to it.
Working memory or short term memory (STM)
STM used to describe the fact that it holds information for a short time, while working memory refers to the processing capacity.
STM works as a temporary holding place for intermediate decisions.
Limited in size.
Chunking
Working memory: there is a limited amount of processing capacity that you can use as you perform a problem
Long term memory
Knowledge of how to do things, things we have learned, grammar rules, personal memories.
All knowledge that is not active.
Information that becomes active is retrieved from LTM and put in STM.
Anything we learn is first processed in STM and some of it is put into LTM
Episodic vs. Semantic Memory distinction
Semantic memory
• Organized knowledge of words, concepts, symbols and objects. motor skills, general knowledge, spatial knowledge , social skills.
• All information is organized semantically, but not tagged based on when it was learned.
Episodic memory
• Holds traces of events specific time and place.
• Memory of personal experiences.
Interaction between semantic and episodic memory
What does the organization of the information processing system have to do
with language processing?
Pattern Recognition
Parsing/understanding sentences in working memory
This is a long sentence and yet somehow you can keep it all in working memory
The organization of Long Term Memory
That cat plays really cool jazz
Serial vs. Parallel Processing
Serial processing: One process working at a time
Parallel Processing: Multiple processes working at a time
In a serial model of language processing, individual modules would work one at a time to process the information.
A parallel model would say that the processes happen at the same time.
Parallel models as neurally inspired models of cognitive processes
Top-Down vs. Bottom-Up processing
Cognitive processing occurs at levels
Bottom-up processing is done in such a way that all processing occurs starting from the lowest level processes and proceeds onto the higher level processes
Higher level processes do not influence any of the processing done at the lower levels
Top down processing: Information at the higher levels influences processing at the lower levels.
Advantages and disadvantages of Top-Down processing
Automatic vs. Controlled processes
We have a limited amount of processes that we can do at a time.
Controlled processing: Processes that require a substantial amount of cognitive processing.
Automatic processing: Processes that do not require a substantial amount of cognitive processing.
The role of practice in automatic processing
The Stroop effect
Putting it all together: Cognitive processes in action
The novice accepted the deal before he had a chance to check his finances, which put him in a state of conflict when he realized he had a straight flush.
The Internal Lexicon
How are words stored? What are they made up of? How are word related to each other? How do we use them?
Internal lexicon The representation of words in long term memory
Lexical Access: How do we activate the meanings of words?
Aspects of Meaning
Reference: The relationship between words and things in the world
Things in the world are referents of a word
My dog has fleas
My dog is from Mars
But not all reference can be mapped to concrete things
Abstract words: Love, Justice, Equality
Non existent objects: Unicorn, Martians
Meaning is not restricted to the real world, but also imaginary worlds
Sense: The relationship of a word with other words in the language
Student at NMSU vs. Undergraduate at NMSU
Synonymy (same meaning)
Car Automobile
Antonymy (opposite meaning)
Happy Sad
Incompatibility (do the words contradict each other?)
John is happy vs. John is sad
Hyponymy (are they part of the same class?)
A dog is an animal, Bowser is a dog,
Denotation vs. Connotation
Denotation: The objective meaning of the word
Connotation: The aspect of the meaning beyond its explicit meaning
Bachelor Spinster
Hungry Starving
The Mental Representation of Meaning
The representation of the meaning of a word is based on the semantic features of that word
We acquire the meaning of a word by learning its semantic features
Children make semantic mistakes
Verbs of possession.
We understand more than the meaning, we have knowledge of the relations between these words
sold vs. paid
give vs. receive
lose vs. find
Prototypes:
Some members of a category are better instances of the category than others
Apple vs. pomegranate
What makes a prototype?
More central semantic features
What type of dog is a prototypical dog
What are the features of it?
We are faster at retrieving prototypes of a category than other members of the category
Semantic Networks
Words can be represented as an interconnected network of sense relations
• Each word is a particular node
• Connections among nodes represent semantic relationships
Mental models:
A model/understanding of how the world works and how pieces of textual information fits in with it.
John is sitting in a chair. That chair is on a table. The table is blue and round. John has red hair.
The structure of the Internal Lexicon
How do these pieces of semantic information relate to each other?
Semantic verification task
An A is a B
An apple is a fruit
A robin is a bird
A robin is an animal
A dog has teeth
A fish has gills
A fish has feathers
An apple has teeth
NMSU is in New Mexico
Harvard is in California
Use time on verification tasks to map out the structure of the lexicon.
Models of the Lexicon
Collins and Quillian Hierarchical Network model
Lexical entries stored in a hierarchy, with features attached to the lexical entries
Representation permits cognitive economy
Testing the model
Sentence Verification time
Robins eat worms 1310 msecs
Robins have feathers 1380 msecs
Robins have skin 1470 msecs
A category size effect: Subjects do an intersection search
Problems with Collins and Quillian model
1) Effect may be due to frequency of association
2) Assumption that all lexical entries at the same level are equal
The Typicality Effect
Which is a more typical bird? Ostrich or Robin.
A whale is a fish vs. A horse is a fish
Major conclusions of the model:
1) If a fact about a concept is frequently encountered, it will be stored with that concept even if it could be inferred from a more distant concept.
2) The more frequently encountered a fact about a concept is, the more strongly that fact will be associated with the concept. And the more strongly associated with a concept facts are, the more rapidly they are verified.
3) Verifying facts that are not directly stored with a concept but that must be inferred takes a relatively long time.
Spreading Activation Models (Collins & Loftus)
• Words represented in lexicon as a network of relationships
• Organization is a web of interconnected nodes in which connections can represent:
categorical relations
degree of association
typicality
Retrieval of information
• Spreading activation
• Limited amount of activation to spread
• Verification times depend on closeness of two concepts in a network
Context effect in spreading activation models
Present either: Murder is a crime or Libel is a crime
Then get verification time for Robbery is a crime
Subjects faster when they see Murder than Libel. Why?
Advantages of Collins and Loftus model
• Recognizes diversity of information in a semantic network
• Captures complexity of our semantic representation
• Consistent with results from priming studies
Lexical Access
What factors are involved in retrieving information from the lexicon?
Semantic Priming
Meyer & Schvaneveldt (1971) Lexical Decision Task
Prime Target Time
Nurse Butter 940 msecs
Bread Butter 855 msecs
Evidence for associative spreading activation
Ratcliff and McKoon (1981)
Subjects study and memorize The doctor hated the book
Task: "Was this word from the sentence you memorized?"
Prime Target Time
None Book 667 msecs
Doctor Book 624 msecs
Word Frequency
Does word frequency play a role in lexical access?
Lexical Decision Task:
gambastya, revery, voitle, chard, wefe, cratily, decoy, puldow, raflot, oriole, vuluble, booble, chalt, awry, signet, trave, crock, cryptic, ewe, himpola
mulvow, governor, bless, tuglety, gare, relief, ruftily, history, pindle, develop, gardot, norve, busy, effort, garvola, match,sard, pleasant, coin, maisle
Lexical Decision is dependent on word frequency
Eyemovement studies:
Subjects spend about 80 msecs longer fixating on low-frequency words than high-frequency words
Morphological Structure
So we strip off the prefixes and suffixes of a word for lexical access?
Decision = Decide + ion
Lexical Decision Tasks:
Snodgrass and Jarvell (1972)
Response times greater for affixed words than words without affixes
Evidence for a stage where prefixes are stripped.
Taft (1981)
Lexical Decision times shorter for prefixed words (remind) vs. pseudoprefixes (relish)
But this does depend on strategy?
If you see many prefixed words you take longer with the pseudoprefixes, but if you see only 10% prefixed words, you don't take any longer
Lexical Ambiguity
Words can have multiple interpretations
The role of frequency of meaning
Hogaboam and Pefetti (1975)
Task, is the last word ambiguous?
The jealous husband read the letter
The antique typewriter was missing a letter
Subjects are faster on the second sentence. Why?
Evidence for more than one node for each word in semantic memory
The role of prior context
Swinney (1979)
Auditory presentation:
Rumor had it that, for years, the government bulding has been plagued with problems. The man was not surprised when he found several spiders, roaches and other bugs in the corner of his room.
Lexical Decision task
Context related: ant
Context inappropriate: spy
Context unrelated sew
Within 400 msecs of hearing "bugs", both ant and spy are primed, but after 700 msecs, only ant is primed
Why activate all aspects of meaning for a word?
Retention of lexical items
How long does it take for studied words to be forgotten?
Wickelgren (1975)
Presented subjects with a sequence of words to study
Examined the probability of recognizing words over 14 days
Performance systematically decays over time
Negatively accelerated decay
Bahrick (1984)
Student's retention of spanish-english vocabulary items from 0 to 50 years
Power law of decay
Review on the internal lexicon
Aspects of meaning:
Reference and Sense
Denotation and Connotation
What is the mental representation of meaning?
Models of the Lexicon
Hierarchical Network Model
Spreading Activation Model
What factors are involved in retrieving information from the lexicon?