Word Learning Biases: Lecture 3A

• Learning words, Lecture 3A, Semester 2 Week 3

Topics to cover

• Biases guiding word learning

Learning Outcomes

First Words Learned

• First words are often "Mummy", "Daddy", and "Baby"
• Other variations include "Mama", "Dada", "Papa", and "Baba"
• In Swahili, mother is "mama" and father is "baba"
• In Kikuyu (East Africa), mother is "nana" and father is "baba"
• In Tagalog (Philippines), mother is "nanay" and father is "tatay"
• In Xhosa (South Africa), mother is "mama" and father is "tata"
• In Pipil (El Salvador), mother is "naan" and father is "tatah"
• In Cree (Canada), mother is "mama" and father is "papa"
• In Mandarin Chinese, mother is "mama" and father is "baba"
• Latin (B.C.E.) uses "pappa" for food
• Spanish uses "papa(*)" for food
• Moroccan Arabic uses "pappa" for bread
• Arabic uses "mamm" for food
• Comanche (USA) uses "papa" for drink
• Marathi (India) uses "mummum" for food
• Gilyak (Outer Manchuria) uses "mama" for food

Referencing

• Reference and mapping are new terms in learning language
• Words have two properties: a form and a meaning
• Words use arbitrary mappings between form/sound and meaning
• The association between the word and the thing it represents is the first thing learned about the new word

Vocabulary Growth

• Vocabulary growth includes a spurt in numbers

Vocabulary size

• Fenson et al. (2000) wrote about how many words a child knows at a certain age

Vocabulary Spurts

• A naming insight can lead to rapid expansion of vocabulary
• Development of segmentable phonological representations of words can lead to rapid expansion of vocabulary
• Development of semantics can lead to rapid expansion of vocabulary
• Semantics include categorical partitioning of objects in the world

Alternative Views on Vocabulary Spurts

• Vocabulary spurts may vary by child
• Some children show little or no evidence of a spurt
• How the "spurt" is defined can impact research
• Disagreement on the specific definition

Vocabulary Increases

• Children show large vocabulary increases from 12 to 24 months
• Vocabulary continues to increase rapidly through the school years

Early Semantics

• Early Semantics include a single word stage

Development of Semantics

• Lexical constraints do not operate alone
• Semantic networks involve associations and connection among words and concepts
• New words add sound-meaning mappings to lexicon
• The semantic system grows richer as more is learned

Biases Guiding Word Learning

• Includes learning what "gavagai" means

The 'Gavagai' Problem (Quine, 1960)

• How does a child know that "rabbit" refers to the animal and not some other property?

Learning Word Meanings Biases

• Several biases(constraints) have been suggested which can guide children in learning the meaning of words, Markman (1992)
• Whole word bias
• Mutual exclusivity
• Taxonomic bias

Whole Object Bias

• Words refer to whole objects
• This is the belief a label refers to a whole object, not a part of it or property
• Object names form the largest proportion of young children’s vocabularies across languages

Alternate Explanations for Whole Object Bias

• Predisposition to perceive whole objects, babies 'chunk' the world into distinct objects
• Theory of Mind, children believe other want to refer to objects.
• Children attend to objects that are salient

Mutual Exclusivity

• Three-year olds presented with a picture of a tool and an unknown object
• Introduced to novel words
• Asked to identify, for example, the "jop"
• Chose the unknown item

Implications of Experiment

• Children apply new words to objects without existing words
• Mutual Exclusivity

Taxonomic Bias

• Children (aged 2-3) were shown a picture of a dog, then shown two more pictures- one of a different breed, and one of dog house.
• Chose the other dog, indicating preference towards things of taxonomic category

Other Strategies for Learning Word Meanings

• Theory of Mind
• Syntactic Bootstrapping
• Conceptual Categories.

Hypothesized Constraints

• Conventionality, using the same words for the same thing
• Shape bias, extending a new term based on shape
• Principle of contrast, distinctions in word signals differences in word signals differences in meaning.

Lexical Constraints on Learning

• It is debated as to whether these constrains are:
  • Purely Lexical.
  • Applications of general cognitive constraints/biases.
  • Artefacts of general learning.

Cognitive Linguistic Mechanisms

• Important to learning words

Syntactic Bootstrapping

• Using syntactic information to learn word meanings
• Describing a pictured action as "sibbing", "a sib", or "some sib" will cause children to associate words with different aspects of the scene, (Brown 1957).
• Children shown a scene of duck pushing rabbit or both waving
  • Children who hear “The duck is gorping the rabbit looked longer at the duck pushing the rabbit
  • Children shown the two screen version of “The rabbit and the duck are gorping, they will correlate the word to mean hand

Linguistic Context

• Preschool children use the meaning of sentences to infer meanings of:
  • Count nouns, “This is a X” - Katz et al., 1974
  • Mass nouns, "This is some X") - Brown, 1985
  • Proper nouns” ("This is X") - Gelman et al., 1984
  • Adjectives("This is a X one/This is very X") - Smith et al., 1992
  • verbs("This is X-ing") - Dockrell & MacShane, 1990

Associative Learning Approach

• Discover words' meanings based on general learning mechanisms (e.g. attention & memory)
• Discovery includes natural statistical co-variation of words and what they refer to
• Referents co-vary with words
• Referents move in temporal coincidence with words

Yu and Smith

• Smith & Yu (2008) found infants learned word object pairs
• This relies on how these co-occurred

Smith Example Experiment

• Use non-words
• Exposure via auditory and visual stimuli
• Dependent variable: gaze – looks to object

The associative learning approach 4

Words Learned Last

• "bosa! … gasser! …" "bosa! … manu!...." "colat! … gasser! …" "gasser! … kaki! …" “colat! … regli! …” "kaki! … bosa! …"

The associative learning approach 5

• These are then tested using the same syntax

Results

• Infants learn word object pairs through trials by learning to follow gaze.

Support From Input

• Adults help children learn word meanings
  • Giving definitions of words ("That's a flower")
  • Corrections
    • Child: "Mummy, where's my plate?"
    • Mother: "You mean your saucer?"
  • Recasts
  • Parents provide word definitions

Conversation Partners

• Children are conversation partners

Impoverished Input?

• The poverty of stimulus argument claims that the nature of input is impoverished/degenerate:
  • Children hear only correct utterances
  • Children often hear fragmentary utterances -Children receive no negative input -How do children work out the system, in particular grammar?

Types of Feedback

• Negative input occurs despite parent rarely correcting syntax -Repititions (more likely to occur with correct utterances) -Recasts- Often new information too. -Expansions. -Clarifications.

Child Directed Speech(CDS)

Infant Directed Speech (IDS)

• More exaggerated form of CDS
  • Some separate classify the two, and the number of IDS / CDS decrease as children age

CDS Universality

• Aspects in languages as diverse as Danish, Chinese, Portuguese, Hebrew, especially in recasts. However, certain studies show other existing cultures do not treat children as conversional partners/ CDS absents adults entirely from the equation

Hart and Risley (1995)

• Investigated effects on differences in input language development
  • Study included all SES groups
  • Found different groups provided different quality and quantity of speech to their children
  • High SES mothers talked to children, using larger vocabularies, complex structure and gesturing. Lower SES more negative/ imperative

Million Word Gap

• By age three high SES children heard 30 million more words than lower SES children

Recap on Word Learning

• Recap includes; mechanics aiding lexical development, impact of cognition, and input children receive

Information

• [email protected] for more information and student hours are Wednesdays 9-11am

Explore biases that guide early word learning. This includes common first words like 'Mama' and 'Papa' across different languages, referencing, and more. Understand cross-linguistic patterns in early language acquisition.