Language Acquisition

Babies and children

Language is universal across the species (every human society, and all its normally developing individuals, has language) Language must be learned as well

Around 1 year: isolated words - concrete nouns Around 2 years: rudimentary sentences in the right syntax Between 2 and 5 years, adult-like utterances Comprehension precedes production

Children are born with innate language learning mechanisms, which emerge through maturation.

The idea that there is a critical period for language acquisition when you are younger, and that the language acquisition device is at its best when you are young.

The grammatical proficiency of a second language declines the older they arrive in the US and learn the language

Atrophy (maturation) in the language learning mechanism (the idea of a critical period) OR Interference from the first language

Background: 90% of Deaf children are born to hearing parents, so there is a great variation in when deaf kids are exposed to and use American Sign Language Critically, there is no first language to get in the way, no possible interference Procedures: Deaf people, all of whom had been using ASL for over thirty years, but were initially exposed to it at different ages Findings: Proficiency in ASL as a function of first exposure is similar to second language proficiency in hearing, in that the later the age of initial exposure, the less proficient they were. This suggests the idea of a true critical period, and not just the first language interfering with the second language Deaf children exposed to sign language early outperform their hearing parents Children impose structure on language even if they don’t get it from the input (parents)

Deaf people in Nicaragua are isolated, so not much of a cohesive sign language. In 1983, and earlier came together to create this Nicaraguan sign language and they are the first cohort Then post-1983 1983 the first cohort teaches the Nicaraguan sign language to the second cohort (second generation)

Procedure: Illustrative Task designed to elicit sign language The task has two signers sitting together, but they have a barrier between them, not allowing them to see the table. One signer is the director and has to describe the photos so that the matcher can identify them. The other signer was the matcher who had to select the photo that the director was describing. The photos were in a matter of perspective, and the question if they would take the perspective of the signer or the perspective of the character in the image. Findings: The first cohort was inconsistent about which perspective they would take. The second cohort was consistent about which perspective they would take: the perspective of the character.

There appears to be a critical period for language learning In new language situations it is these children that drive language innovation/creation.

Children learn nouns earlier than verbs and other grammar There is an input-output mismatch because the input from adults towards children is 30% nouns and 10% verbs, yet the output that children say is majority nouns.

Conceptual Change Hypothesis Learning from Observation Hypothesis

Concepts for nouns are easier for babies to understand Verbs are complex, so nouns are simply easier to understand

Babies are smarter than you think. The requirement to learn solely from observation of the referent world favors words that map onto concrete, highly imaginable concepts. Nouns are easier to learn from observing the world

Aim: Do adults have trouble learning verbs under the human simulation paradigm? According to the conceptual change hypothesis, they should not have difficulty learning verbs since adults have conceptually complex concepts. But should have difficulty if it is a matter of observation Procedure: Put adults in the position of children learning first words by having them try to learn verbs and nouns from observation of the referent world alone. Video 6 mothers with 18-24-month-old children Select for analysis 24 most frequent nouns and 24 most frequent verbs Present these to adults for identification Permit only observation of the referent world, nothing more: no audio Findings: Accuracy is much better for nouns than for verbs Conclusion: When it comes to learning from observation words that label things that are easier to see are easier to learn

Syntactic bootstrapping

Learning words helps you learn the grammar Learning the grammar helps you learn words Children use their knowledge of a language’s grammatical structure to infer the meaning of new words, especially verbs Using knowledge of syntax to bootstrap word learning

Aim: The idea that babies learn from frames alone Procedure: Have two participants have a conversation in front of a 24-month-old. In one condition, the baby heard “Jane blicked the baby”, “Really? Jane blicked the baby?” They then have people act out a random thing but one option was between two people and the other option was a singular person. Then ask the baby: “Where’s blicking?” In the other condition, the baby heard “The baby blicked”, “Really? The baby blicked?” They then have people attack out a random thing but one option was between two people and the other option was a singular person. Then ask the baby: “Where’s blicking?” Finding: Depending on the syntactic structure of the sentence, the baby was able to point at which is probably the meaning of blicking. In the first condition, the structure made blicking something between two people, so the baby chose the action with two people. In the second condition, the structure made blicking something only one person did, so the 24-month-old chose the action with one person.