Week 6 - Language Development

Phonology

System of sounds (Phonemes, e.g. ‘b’ vs ‘d’)

Semantics

Meaning of words and combinations

Grammar

Structure of language (arranging words into sentences)

Pragmatics

Social rules for language (context use, turn taking etc.).

Effective social communication.

Language development requires:

• Comprehension

• Production

Learning/Empiricist perspective of language development

Skinner (1957) - children are reinforced with grammatically correct speech.

Adults shape children’s speech by selectively reinforcing babbling that sounds like words.

Once words have been shaped, reinforcement is withheld until child begins to combine words.

Learning perspective of language development

Bandura (1971) - children listen and imitate language of older companions, caregivers teach language by modelling language

Nativist perspective of language development

Humans are biologically programmed to acquire language.

• Chomsky - language acquisition device (LAD)

• Slobin (1985) - language-making capacity (LMC)

• Sensitive periods

Chomsky’s language acquisition device (LAD)

An inborn linguistic processor that is activated by verbal input, contains a universal grammar

Slobin’s (1985) language-making capacity (LMC)

Children have this inborn LMC, which is a set of cognitive/perceptual abilities highly specialised for language learning

Interactionist perspective of language development

Results from complex interplay of biological maturation, cognitive development and linguistic environment.

Suggests children worldwide develop language at similar pace because members of same species.

Children biologically prepared to learn language not because of LAD/LMC but because they have powerful brain that matures slowly - language develops as children communicate with people.

Factors affecting language development

• Damage to left hemisphere

• Sensitive periods

• Experience (child-directed speech, non-verbal games)

Damage to left hemisphere leads to…

Aphasisa - a communication disorder that makes it difficult to speak, understand language, read, and write

Broca’s area affects…

Speech production

Wernicke’s area affects…

Speech comprehension

Sensitive periods

Times in development when the brain is particularly receptive to learning language skills.

E.g. case of Genie who was brought up with dogs and never learned language.

Child-directed speech

Close proximity, exaggerated facial expressions, repetition, higher pitched voice.

• Natural in most cultures.

• Parents gradually increase length and complexity of child-directed speech as children get older

Playing non-verbal games

Teaches turn-taking, e.g. pat-a-cake, peek-a-boo

Prelinguistic phase

From birth to 6-months, although infants start to process sounds in the womb (DeCasper & Spence, 1986)

Cat in the womb study

Showed infants preferred to listen to intonation of the passages they had been read prenatally.

• 1-2mth infants discriminate between different phonemes.

• Discrimination includes speech sounds across different languages.

• This decreases at 6-12 months (Werker & Tees, 2005)

Preparation for speech production

• Different patterns of crying (hunger, anger, pain), increasingly social in nature.

• Cooing from 1 month

Cooing

Making repetitive vowel sounds signalling pleasure, varying in volume and pitch

Proto-conversations

Bateson (1975) - mothers tend to vocalise when their infants have finished vocalising, which stimulates turn-taking.

These interactions evolve into triadic interactions when infants point to objects:

• Proto-imperative - requests for objects/actions

• Proto-declarative - comments on objects/actions

Development of speech production

• 1 month - cooing and laughing

• 4-6 months - babbling and vocal play

• 6-10 months - canonical babbling

Canonical/reduplicated babbling

Babbling repetitive vowel-consonant combinations.

• Gradually develop intonation

• Shift to sounds that are heard most (combinations of sounds that sound like words)

Receptive language

Ability to understand and comprehend spoken language.

Evidence of receptive language before expressive language.

Fenson (1994)

Examined mother's’ report of number of words understood by infants.

• 10 months = 30 words

• 13 months = 100 words

Bergelson & Swingley (2012)

Infants begin associating highly familiar words with highly familiar referents surprisingly early.

• At 6-9 months, infants knew meaning of many common nouns

• Most parents did not realise this

How do infants learn meaning of words

Learning in ‘constraint’ - (e.g. whole object constraint, mutual exclusivity constraint)

• Children construct semantic system of words relating to one another

• Facilitated by their acquisition of semantic relations

• Learn that objects can be referred to by more than one word and how words relate to one another (e.g. opposites)

• Helps children identify gaps in vocab

Production of first words

10-15 months, can be of any sound but they are used consistently in presence of object/situation.

They condense meaning (e.g. “want milk”).

Holophrase period

12-18 months, using a single word for a whole phrase

Overextension

One word applied in a broader context than is appropriate

Vocabulary spurt

16-24 months

Nelson (1973)

First words tend to be nominals (ball, dog), then specific nominals (mummy) and action words (give, bye bye)

Facilitators of vocab spurt

Parents:

• Label, stress, repeat new words

• Play naming games

• Introducing new words depending on context

• Spatial consistency

Children:

• Fast mapping

• Using pragmatic cues

• Inferring meaning

• Cross-situational word learning

Spatial consistency

Infants learn label of objects more readily when object is in same location each time they are labelled

Fast mapping

Process of rapidly learning new word from context, e.g. hearing the contrastive use of a familiar and unfamiliar word

Pragmatic cues

Eye gaze, labelling

Inferring meaning

Taking cues from linguistic context and syntactic bootstrapping (children learn word meanings by using the grammatical structure of sentences)

Cross-situational word learning

Repeated correspondence between words heard and objects observed

Brown (1973)

First sentences combining two words came at around 18-24 months.

Telegraphic speech - short and simple, grammatical markers missing, may reflect multiple meanings depending on context

Fenson et al. (1994)

Very strong correlation between vocab size and complexity of child’s sentences

Grammar development at 2-3 years

• Telegraphic speech ceases

• Add inflections (e.g. ‘ing’ added to verbs)

• Beginning to form questions and negatives

Grammar development at 3-4

Overregularisation.

• Apply very basic rules to irregular words (e.g. ‘ed’ applied to all verbs to form past tense)

• But form more complex sentences using conjunctions (‘and’, ‘but’) to connect two or more ideas, embedded clauses

When is there major strides in grammar

Between 1-4 years

Hart & Risley (1995)

Differences in children’s vocab size and amount parents talked to their children was dependent on social class - much lower for working class

DeLoache et al. (2010)

Infants who learn from parents performed best.

Infants in video-learning condition did not perform better than in control condition.

Newport and Johnson (1989)

• The ability to learn languages declines after children reach the age of approximately

• Before the age of 7, children can learn a second language with similar proficiency to native speakers.

"Whole object constraint" refers to the idea that

Children expect that a word will always refer to a whole object

What is “mutual exclusivity” in word learning?

Children assume a new word refers to an unfamiliar object

Telegraphic speech

Simple two-word phrases missing grammatical markers

Werker & Tees (2005) found that children's ability to discriminate between different language sounds decreased at _____ months because of neural commitment. This is a characteristic of the prelinguistic phase.

6-12 months