Lecture 15: Foundations of Language Development

Foundations of Language Development

Introduction
  • Language is a fundamental aspect of being human, distinguishing us from animals.
  • Animals can be taught words (e.g., monkeys, up to 50 words), but their communication is unlike human language.
  • Language permeates human activities: friendships, gossip, culture, knowledge, and even physical activities like sports (rules, strategies).
Current Trends Shaping Language Development
  • Large Language Models (LLMs): Shed new light on old debates like nature versus nurture.
  • Naturalistic Studies: Track language acquisition outside the lab using audio and video recordings from birth to age five.
  • Bilingualism: Recognizing the importance of studying languages other than English.
    • Speaking multiple languages can delay cognitive decline.
Key Questions in Language Development
  • How do children acquire language seemingly effortlessly?
  • Is language learning innate or learned from the environment?
  • Is language-specific learning or general cognition?
  • What causes individual variation in the rate of language acquisition?
  • Is there a critical period for language exposure?
Components of Language
  • Understanding rules of grammar.
  • Knowing word meanings.
  • Segmenting speech into words (word segmentation).
  • Understanding sounds or phonemes.
The Great Debates: Nature vs. Nurture
  • Nature: Innate capacities or structures.
  • Nurture: Gains from experience.
  • Extreme views of either nature or nurture alone are incorrect.
  • Language learning differs from abilities like crawling, which develops automatically.
  • Key question: Is language acquisition a specific type of learning or a case of general cognitive learning?
Sub-questions:
  • Are humans different from animals in terms of understanding grammar, or is it general intelligence?
  • Are there specific brain areas/modules for language learning?
  • Do we need special assumptions to make language learning possible?
  • Is there a critical period?
Theoretical Approaches
1. Behaviorist View
  • Language as classical conditioning.
  • General learning mechanism based on imitation and positive reinforcement.
  • Example: Infant makes "dada" sound, father encourages, positive feedback until it resembles "daddy".
  • Highlights external reinforcement.
  • Adult-like words are rewarded.
  • Problem: Doesn't account for rules and abstract knowledge inferred from input.
  • Skinner argued language learning is a function of environment and reinforcement without innate language mechanisms.
2. Nativist View
  • Chomsky argues for innate knowledge that enables language learning.
  • Shortcomings of behavioral approach:
    • Poverty of the stimulus: Input is not rich enough for complex rules inferred.
    • Speed and universality: All children learn language efficiently.
    • Creative use of language: Generating new sentences.
  • Suggests a universal grammar.
  • Innate Language Acquisition Device (LAD).
3. Statistical Learning View
  • Language learned like anything else.
  • Highlights the role of experience, contrasting with innate principles.
  • Relies on sensitivity to statistical regularities in the environment (language and perceptual).
  • Emphasizes implicit learning (no feedback).
4. Social Interactions View
  • Language occurs in a social context.
  • Parents shape the learning curriculum (e.g., shared book reading).
  • Highlights language acquisition taking place alongside other social skills (turn-taking, mutual gaze, joint attention).
Human vs. Animal Language Learning
  • Is it a matter of intelligence or specific language aspects?
Example: Alex the Parrot
  • Trained by Irene Peppenberg.
  • Learned about 80 words (object names, verbs, adjectives).
  • Produced short, novel sentences (e.g., "yummy bread" for birthday).
  • Classified objects based on shape and color.
  • Limitations: Difficulty with function words (prepositions) and verbs.
  • Trained in a behaviorist tradition (rewarded).
Example: Kanzi the Bonobo
  • Trained from a young age with his mother using a lexigram system (symbolic language).
  • Observational learning (no rewards).
  • Produced grammatical constructions.
  • Understood "put the soap on the apple".
  • Limitations: Challenges with function words, limited morphology (plurals), and grammar (complexity).
  • Highlights the social aspect of language learning.
  • Qualitative differences, quantitative difference.
Language Representation in the Brain
Broca's Area
  • Left inferior frontal gyrus.
  • Speech production
  • Adjacent to the part of the brain that controls the jaws, lips, and tongue
Wernicke's Area
  • Perception and meaning of words.
  • Adjacent to the primary auditory area.
Aphasia
  • Aphasias result from trauma, blunt objects, or brain tumors
Broca's Aphasia
  • Problems with grammar.
  • Speech is poorly articulated and ungrammatical.
Wernicke's Aphasia

  • Fluent speech but doesn't make sense (gibberish).

  • Difficulty accessing the right verbs, nouns, adjectives.

  • Lacking in overall sense.

  • Localization may not be strong argument for language specificity and language is more represented in an interspersed way in the brain.

  • The more advanced functions of language tend to be spread out throughout the whole entire cerebral cortex.

Poverty of the Stimulus Argument & Universal Grammar
  • Children can understand an infinite number of new sentences.
  • Nativists: Reflects an innate capacity.
  • Rules for sentences are non-obvious.
  • Example: "Yes, he is" vs. "Yes, he's".
  • Children learn rules through feedback (behaviorist approach).
    • Limitation - there is not enough feedback. Carers provide feedback about the truth of sentences, but do not correct grammar.
  • Nativist solution: Universal Grammar - A set of primitives and rules of inference that allow you to learn even if you have limited input. Learning is a matter of parameter setting.
Linguistic Universals
  • American linguist, Joseph Greenberg, compared the syntax of several languages across the world and he found several of these universals.
Types of Universals:
  • Absolute Universals: Shared across all languages (e.g., no language forms questions by reversing word order).
  • Statistical: Holds for most languages (e.g., subject precedes object).
  • Implication of Universals: If a language has feature x, it will also have feature y (e.g., Japanese (SOV) needs to have a question word at the end of the sentence).
  • Broad Universal: All languages have nouns and verbs. All languages have consonants and vowels to make up words.
Example of an adjective ordering preference that demonstrates Linguistic Universals:
  • "a big black bag" vs "a black big bag"
  • Cognitive View: The ordering of adjectives is not necessarily strict but is an ordering of preferences.
  • The Linguistic View is that this kind of information is hardwired.
Experiment:
  • In an experiment, participants were asked to judge congruent adjectives and incongruent adjectives on a three-point scale. Most participants endorsed them regardless of being congruent or incongruent but they have a preference for putting the congruents next to each other.
  • Cognitive biases as potential explanation: Novel Information Bias, You move unexpected of surprising information to the front of a series of adjectives to make it easier to parse the message. This is an example of many other cognitive biases to could contribute to this in tandem.
    • The Universal Grammar is biologically implausible.
Large Language View
  • Language is creative. It generates sentences that they've never seen before and does not required explicit evidence.
Critical Period Question
  • Is there a critical or sensitive period for language learning?
  • Idea of imprinting.
  • Importance of early language exposure to get fluent.
  • Does this also hold for language?
Studies of Feral Children
  • Children are deprived of language inputs in the beginning of life.
  • Limitations, there are many confounds and children are traumatized and socially deprived.
Deaf Children
  • One study that looked at British Signing, found that participants learned sign language from the moment they were born or from 5-8 and those that learned it later. Study found the group in the middle, that are learning it later did not perform well.
Language Learners
  • One study, determined that our learning capacity stays quite stable up to the age of 17 and then there seems to be late critical periods.
The Inputs
  • Rich get richer, the more input you get the better you become at processing an input, the more you learn
Starting Small
  • Also known as, The less is more principle.
  • The idea is the very young children have limited cognitive resources for working memory, but this will actually help them learn language.
  • Adults can learn a language better if they are presented tiny small segments of the language. Say for example the objects.
Social Interaction
  • Infants prefer listening to child directed speech over adult directed speech.
Child Directed Speech (CDS)
  • There are dialects in how adults will speak to children
  • Speak slower with more pauses
  • Will convey happy/positive affects.
  • Simplify things and give the children the correct information in this way
2 Views:
  • The adult should speak their language in a way that is quite relevant for the acquisition.
  • It helps children learn a language, so it should about the adults trying to make themselves understood.
  • Language lessons are a side product of CDS.
Different Forms of Social Interaction:
  • Six-month old are more sensitive to adults that use sing-song voices.
  • Children were test for teaching them a new phenomic contrast and were exposed, in front of group or with none.
  • This suggests that the social dimension in learning is highly important and the presence of a person increases the attention to acoustic properties.
  • If the children do watch lots of TV, they kind of discount any kind of language that doesn't require active participation as irrelevant.
Summary
  • Language exposure matters.
  • Starting small helps.
  • Child-directed speech might not be necessary, but it certainly helps language learning.