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PSY 369: Psycholinguistics. Language Acquisition. Announcements. On-line Blackboard quiz for chapter 4 is now up. You may take it 5 times, top score counts I am pushing Exam 2 back a day. We will have the exam on Feb. 28.
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PSY 369: Psycholinguistics Language Acquisition
Announcements • On-line Blackboard quiz for chapter 4 is now up. • You may take it 5 times, top score counts • I am pushing Exam 2 back a day. We will have the exam on Feb. 28. • Language development section includes information from Chapter 3, pages 72-87 • Homework #2 due today
Language explosion continues • The language explosion is not just the result of simple semantic development; the child is not just adding more words to his/her vocabulary. • Child is mastering basic syntactic and morphological processes.
Syntax • Take 100 utterances and count the number of morphemes per utterance Mean length of utterance (MLU) in morphemes Daddy coming. Hi, car. Daddy car comed. Two car outside. It getting dark. Allgone outside. Bye-bye outside. # morphemes: 3, 2, 4, 3, 4, 2, 2 ‘-ing’ and ‘-ed’ separate morphemes ‘allgone’ treated as a single word MLU = morphemes/utterances = 20/7 = 2.86
Language explosion continues • Proto-syntax (??) • Holophrases (around 1-1.5 years) • Single-word utterances may be used to express more than the meaning usually attributed to that single word by adults “dog” might refer to the dog is drinking water • Typically idiosyncratic, but some conventional/common (e.g., indicate the existence of an object, request recurrence of object or event) • Often combined with intonation or gesture • Controversial claim: May reflect a developing sense of syntax, but not yet knowing how to use it (e.g., see Bloom, 1973)
Language explosion continues • Syntax • Roger Brown (1973) proposed 5 stages (determined by MLU not age) • Stage 1: Telegraphic speech (MLU ~ 1.75; around 24 months) • Children begin to combine words into utterances • Limited to a small set (11) of semantic relations (75% of their utterances) Nomination “That ball” Recurrence “More ball” Nonexistence “Allgone ball” Agent & action “Daddy hit” Action & object “hit ball” Agent & object “Daddy ball” Action & locative “go store” Entity & locative “book table” Entity & attribute “big house” • Debate: learning semantic relations or syntactic (position rules) • “baby sleep” agent & action or Noun Verb • Children in telegraphic speech stage are said to leave out the ‘little words’ and inflections: • e.g. “Mummy shoe”NOT Mummy’s shoe • “Two cat”NOT two cats
Language explosion continues • More than two words • Stages 2 through 5 • Stage 2 (MLU ~2.25) • begin to modulate meaning using word order (syntax) • Modulations for number, time, aspect • Gradual acquisition of grammatical morphemes (“-ing”, “-s” • Later stages reflect generally more complex use of syntax (e.g., questions, negatives) • Syntax • Roger Brown (1973) proposed 5 stages
Acquiring Syntax • Innateness accounts • Semantic bootstrapping (e.g., Pinker 1984, 1989) Child has innate knowledge of syntactic categories and linking rules Child learns the meanings of some content words Child constructs some semantic representations of simple sentences Child makes guesses about syntactic structure based on surface form and semantic meaning • Learned accounts • Acquired from the linguistic input from the environment (e.g. Bates, 1979) • Speech to children is not impoverished (Snow, 1977): Child-directed speech • Similar words occur in similar linguistic contexts • Acoustic information (e.g., prosody) may provide syntactic cues • Children learn grammar by mapping semantic roles (agent, action, patient) onto grammatical categories (subject, verb, object)
Acquiring Morphology • Morphology • Typically things like inflections and prepositions start around MLU of 2.5 (usually in 2 yr olds) • Kids acquire the “rules” for applying morphology • Wug experiment (Berko-Gleason, 1958) This person knows how to rick. She did the same thing yesterday. Yesterday she ________. Typically children say that she “ricked.”
Acquiring Morphology • Morphology: order of acquisition is relatively consistent (James & Kahn, 1982)
Acquiring Morphology • Children sometimes make mistakes. My teacher holded the baby rabbits. Yes She holded the baby rabbits. No, she holded them loosely. Did you say your teacher held the baby rabbit? What did you say she did? Did you say held them tightly?
Acquiring Morphology • Children sometimes make mistakes. • This is ungrammatical in the adult language • Shows that children are not simply imitating • In this case, what they produce something that is not in their input. My teacher holded the baby rabbits.
Acquiring Morphology • Children sometimes make mistakes. • Why do they make errors like these? • In the case at hand, we have what is called overregularization • The verb hold has an irregular past tense form, held • Because this form is used, the regular past tense-- that with -ed-- is not found (*hold-ed) My teacher holded the baby rabbits.
Acquiring Morphology • Examples: • Horton heared a Who • I finded Renée • The alligator goed kerplunk • The case of verb past tense: • Regular verb forms require no stored knowledge of the past tense form (wug test) • Past tense is accomplished by applying a past tense rule (e.g., add -ed) to the verb stem • With irregular verbs something must be memorized
Acquiring Morphology • Stages in the acquisition of irregular inflections • The case of verb past tense: • With regular verbs, the default form -ed is used • With irregulars, lists associating the verb with a particular form of the past tense have to be memorized: • Past tense is -t when attached to leave, keep, etc. • Is -> was • Dig -> dug • Has -> had
Acquiring Morphology • Stages in the acquisition of irregular inflections time • On the face of it, learning these morphological quirks follows a peculiar pattern: • Early: correct irregular forms are used • Middle: incorrect regular forms are used • Late: correct forms are used again
Memory & Rules • Why do we find this type of pattern? • Memory and rules • The use of overregularized forms starts at around the same that that the child is beginning to apply the default -ed rule successfully • Early: All forms-- whether regular or irregular-- are memorized • Middle: The regular rule is learned, and in some cases overapplied • Late: Irregulars are used based on memory, regulars use the rule (the idea is that if the word can provide its own past tense from memory, then the past tense rule is blocked)
Memory & Rules • Why do we find this type of pattern? • Memory and rules • Other accounts • Maratsos (2000) – frequency explanation • It is possible to predict which verbs will be subject to overregularization • The more often an irregular form occurs in the input, the less likely the child is to use it as an overregularization • This is evidence that some part of overregularization occurs because of memory failures • Something about irregulars is unpredictable, hence they have to be memorized
What kind of “teaching” do kids get? • If language is learned (and not innate), how do kids do it? • What kind of feedback do they get? • Positive evidence: Kids hear grammatical sentences • Negative evidence: information that a given sentence is ungrammatical • Poverty of the stimulusClaim: Positive evidence is not sufficient for learning a language.
What kind of “teaching” do kids get? • Are the kids even aware of mistakes? • The children are apparently aware of the fact that their forms are strange: • Parent: Where’s Mommy? • Child: Mommy goed to the store • Parent: Mommy goed to the store? • Child: NO! Daddy, I say it that way, not you
What kind of “teaching” do kids get? • How much Positive Evidence is there (in Child-Directed speech)? • Estimated 5000 – 7000 utterances a day • Between ¼ and ⅓ are questions • Over 20% are not “full” adult sentences (typically Noun or Prepositional phrases) • Only about 15% have typical English SVO form • Roughly 45% of all maternal utterances began with one of 17 words (e.g., “what”, “that”, “it”, “you”) Cameron-Faulkner, et al (2003) • So what kids do hear may be somewhat limited.
What kind of “teaching” do kids get? • Negative evidence could come in various conceivable forms. • Upon hearing “Bill a cookie ate”, an adult might • Grammar teacher parent feedback? • “The sentence Bill a cookie ate is not a sentence in English, Timmy. No sentence with SOV word order is.” • More realistic • Not understand • Look pained • Rephrase the ungrammatical sentence grammatically • “Bill at a cookie.”
Kids resist instruction… McNeill (1966) • Child:Nobody don’t like me. • Adult:No, say ‘nobody likes me.’ • Child:Nobody don’t like me. [repeats eight times] • Adult:No, now listen carefully; say ‘nobody likes me.’ • Child:Oh! Nobody don’t likes me.
Kids resist instruction… Cazden (1972) (observation attributed to Jean Berko Gleason) • Child:My teacher holded the baby rabbits and we patted them. • Adult:Did you say your teacher held the baby rabbits? • Child:Yes. • Adult:What did you say she did? • Child:She holded the baby rabbits and we patted them. • Adult:Did you say she held them tightly? • Child:No, she holded them loosely. • So there doesn’t seem to be a lot of explicit negative evidence, and what there is the kids often resist
Negative evidence via feedback? • Do kids get “implicit” negative evidence? • Do adults understand grammatical sentences and not understand ungrammatical ones? • Do adults respond positively to grammatical sentences and negatively to ungrammatical ones?
Negative evidence via feedback? Brown & Hanlon (1970): Case study of “Adam” - looked at things that were said to him by adults, and what he said to them • Adults understood 42% of the grammatical sentences. • Adults understood 47% of the ungrammatical ones. • Adults expressed approval after 45% of thegrammatical sentences. • Adults expressed approval after 45% of the ungrammatical sentences. Suggests that there isn’t a lot of good negative evidence.
In a way, it’s moot anyway… • One of the striking things about child language is how few errors they actually make. • For negative feedback to work, the kids have to make the errors (so that it can get the negative response). • But they don’t make enough relevant kinds of errors to determine the complex grammar. • Pinker, Marcus and others, conclude that much of this stuff must be innate. • But this isn’t the only view. There is an ongoing debate about whether there are rules, or whether these patterns of behavior can be learned based on the language evidence that is available to the kids
Critical (sensitive) periods • Certain behavior is developed more quickly within a critical period than outside of it. This period is biologically determined. • Examples: • Imprinting in ducks (Lorenz, ; Hess, 1973) • Ducklings will follow the first moving thing they see • Only happens if they see something moving within the first few hours (after 32 hours it won’t happen) of hatching • Binocular cells in humans • Cells in visual system that respond only to input from both eyes. • If these cells don’t get input from both eyes within first year of life, they don’t develop
Critical (sensitive) periods • Certain behavior is developed more quickly within a critical period than outside of it. This period is biologically determined. • Some environmental input is necessary for normal development, but biology determines when the organism is responsive to that input. • That “when” is the critical period
Critical period for language • Lenneberg (1967) proposed that there is a critical period for human language • It assumes that language acquisition must occur before the end of the critical period • Estimates range from 5 years up to onset of puberty
Evidence for critical period for language • Feral Children • Children raised in the wild or with reduced exposure to human language • What is the effect of this lack of exposure on language acquisition? • Two classic cases • Victor, the Wild Boy of Aveyron • Genie
Victor, The Wild Boy of Aveyron • Found in 1800 near the outskirts of Aveyron, France • Estimated to be about 7-years-old • Considered by some to be the first documented case of autism • Neither spoke or responded to speech • Taken to and studied by Dr. Jean-Marc-Gaspard Itard, and educator of deaf-mute and retarded children • Never learned to speak and his receptive language ability was limited to a few simple commands. • Described by Itard as “an almost normal boy who could not speak”
Genie • Found in Arcadia, California in 1970, was not exposed to human language until age 13.5. • Raised in isolation a situation of extreme abuse • Genie could barely walk and could not talk when found • Dr. Susan Curtiss made great efforts to teach her language, and she did learn how to talk, but her grammar never fully developed. • Only capable of producing telegraphic utterances (e.g. Mike paint or Applesauce buy store) • Used few closed-class morphemes and function words • Speech sounded like that of a 2-year-old
Genie • By age of 17 (after 4 years of extensive training) • Vocabulary of a 5 year old • Poor syntax (telegraphic speech mostly) • Examples • Mama wash hair in sink • At school scratch face • I want Curtiss play piano • Like go ride yellow school bus • Father take piece wood. Hit. Cry.
What Do These Cases Tell Us? • Suggestive of the position that there is a critical period for first language learning (in particular for syntax and phonological development) • If child is not exposed to language during early childhood (prior to the age of 6 or 7), then the ability to learn syntax will be impaired while other abilities are less strongly affected • Not uncontroversial: Victor and Genie and children like them were deprived in many ways other than not being exposed to language • Genie stopped talking after age 30 and was institutionalized shortly afterward (Rymer, 1993)
What Do These Cases Tell Us? • Suggestive of the position that there is a critical period for first language learning (in particular for syntax and phonological development) • Why? • Nativist explanation (see pg 79 of text) • Maturational explanation: “less is more”
Second language learning • Learning a new language • What if we already know one language, but want to learn another? • Adults learning another language typically have a persistent foreign accent – perhaps a critical period for phonology (Flege & Hillenbrand, 1984) • Adults typically do better initially at learning a new language compared to kids, but kids typically do better over the long term (Krashen, Long, & Scarcella, 1982)
Second language learning • Johnson and Newport (1989) • Native Chinese/Korean speakers moving to US • Task: Listen to sentences and judge whether grammatically correct R = -.87 Test score 2 17 Age of arrival R = -.16 Test score 17 40 Age of arrival
Second language learning • Johnson and Newport (1989) • Native Chinese/Korean speakers moving to US • Task: Listen to sentences and judge whether grammatically correct • Concluded that around the age of 16 something happens • Different factors operate on language acquisition before and after the age of 16 • Birdsong and Molis (2001) • Replicated the Johnson and Newport study in Spanish/English speakers. • Did not find a discontinuity around the age of 16
Effects of the Critical Period • Learning a language: • Under 7 years: perfect command of the language possible • Ages 8- c.15: Perfect command less possible progressively • Age 15-: Imperfect command possible • But these claims are far from universally accepted
Bilinguals & Polyglots • Many people speak more than one language • Tucker (1999) - multilinguals outnumber monolinguals • What is the impact of knowing/using more than one language? • Factors affecting second language acquisition? • What does the lexicon look like? • Interesting effects in bilinguals • Interference • Code switching • Cognitive advantages
Second language acquisition • Contexts of childhood bilingualism • Simultaneous • Both languages are acquired at the same time • Vocabulary growth of bilinguals is similar to that of monolinguals • Some aspects of acquisition may be slowed, but by age of 4 typically caught up • Doesn’t seem to matter whether languages are “related” or not (e.g., English - French versus English Japanese) • Can achieve “fluency” in both languages • Sequential acquisition • The second language is learned after a first language • When the second language (L2) is acquired is important • Early versus late learning (e.g., see the Johnson and Newport study)
Second language acquisition • Frequency of usage of both languages • How often and in what contexts do you use the two languages • “Use it or lose it” - language attrition • Mode of acquisition • Native bilingualism - growing up in a two language environment • Immersion - schooling provided in a non-native language • Submersion - one learner surrounded by non-native speakers • Language dominance effects • Relative fluency of L1 and L2 may impact processing
Bilingual Representations • How do we represent linguistic information in a bilingual lexicon? • Probably depends on many of the factors just discussed • Let’s look at some models and research focusing on the situation where L1 is dominant relative to L2
Word Association Model Concept Mediation Model L1 L2 CONCEPTS CONCEPTS L1 L2 Models of the bilingual lexicons Potter et al (1984): Separate Stores Models – separate lexicons for each language L1=First Language L2=Second Language
L1 & L2 CONCEPTS Models of the bilingual lexicons Paivio, Clark, & Lambert (1988): Common Stores Models – words from both languages in same store L1=First Language L2=Second Language
concepts conceptual conceptual links links lexical links L2 L1 Revised Hierarchical Model • The results are mixed, supporting more complex models • May be different in different bilinguals depending on things like age of acquisition, relative proficiency, etc. • Kroll & Stewart (1994) • Proposed that the fluency of L2 needs to be considered in the processing model
Interesting effects in bilinguals • Interference • Code switching • Cognitive advantages
Interesting effects in bilinguals • Interference • Does knowing two languages lead to interference? • When found, interference is at multiple levels • Phonological - least amount of interference • Lexical - mixing words from different languages • Initially, appear to use a one word per thing strategy • But as they realize there that they’re speaking two language, then they’ll use words from both languages simultaneously • Syntactic • Until year two, may use only one syntactic system which is common to both languages • Then a brief period with two sets of lexical items, but still a common syntax • Finally, two lexicons and two sets of syntax