PSY 369: Psycholinguistics Language Acquisition II

Where to from here? Learning Morphology Critical periods in language learning Bilingualism Language, culture, and thought Left out: Language and the brain Read the chapter, take the quiz, but no lecture and won’t appear on final exam

Morphology Typically things inflections and prepositions start around MLU of 2.5 (usually in 2 yr olds) Wug experiment (Berko-Gleason, 1958) Language explosion continues

Morphology Language explosion continues This person knows how to rick. She did the same thing yesterday. Yesterday she ________. Typically children say that she “ricked.”

Acquiring Morphology OrderMorphemeExample(s) 1Present progressiveI driving 1-2PrepositionsIn, on 4PluralBalls 5Irregular past tenseBroke, fell, threw 6PossessiveDaddy’s chair 7Uncontractible copulaThis is hot 8ArticlesA, the 9Regular past tenseShe walked 10 -> 13…… Table 11.2 in text

Acquiring Morphology 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. Children sometimes make mistakes. I holded the baby rabbits.

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) Acquiring Morphology Children sometimes make mistakes. I holded the baby rabbits.

Regular and irregular forms Examples: Horton heared a Who I finded Renée The alligator goed kerplunk Remember that regular 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 Whereas something must be memorized with irregulars

Stages in the acquisition of irregular inflections Acquiring Morphology 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 Why do we find this type of pattern? Memory and rules

Memory & 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 It is possible to predict which verbs will be subject to overregularization We find a frequency effect 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 has to be memorized

Interim Summary Overregularization looks at first like children are moving backwards On closer examination, the child’s overall performance is improving The pattern of overregularization provides a window on the process in which the child (over)generalizes a rule So how is the rule learned (learnt?)

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

Positive and negative evidence Positive evidence: Kids hear grammatical sentences Negative evidence: information that a given sentence is ungrammatical Kids are not told which sentences are ungrammatical (no negative evidence) Let’s consider no negative evidence further… What kind of feedback is available for learning?

Negative evidence Negative evidence could come in various conceivable forms. “The sentence Bill a cookie ate is not a sentence in English, Timmy. No sentence with SOV word order is.” Upon hearing Bill a cookie ate, an adult might Not understand Look pained Rephrase the ungrammatical sentence grammatically

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?

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 the grammatical sentences. Adults expressed approval after 45% of the ungrammatical sentences. Suggests that there isn’t a lot of good negative evidence. Negative evidence via feedback?

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 a raging 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 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 Certain behavior is developed more quickly within a critical period than outside of it. This period is biologically determined.

Critical period for 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 Lenneberg (1967) proposed that there is a critical period for human language

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 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 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)

Effects of the Critical Period Learning a language; Under c. 7 years: perfect command of the language possible Ages c. 8- c.15: Perfect command less possible progressively Age 15-: Imperfect command possible In some special cases, we are given a window on the nature of the critical period

Effects of the Critical Period Learning a new language What if we already know one language, but want to learn another?

Effects of the Critical Period Johnson and Newport (1989) Native Chinese/Korean speakers moving to US Task: Listen to sentences and judge whether grammatically correct