Language Development Notes

Language Development

Four Elements of Language

  • Phonology: The sounds of a language.
  • Semantics: Words and their meaning.
  • Syntax: Rules that specify how words are combined to form a sentence.
  • Pragmatics: Communicative functions of a language.

Phonology: Perceiving Speech

  • Infants can distinguish most phonemes, many by 1 month after birth (Aslin, Jusczyk & Pisoni, 1998).
  • Children can hear a wide range of phonemes until about 10-12 months (Kuhl et al., 2006).
  • After 10-12 months, children start to specialize in the phonemes of their native language.

Phonology: Identifying Words

  • Infants must identify recurring patterns of sounds (words) within a string of sounds.
  • 7-8-month-olds can recognize words and sound patterns they have heard repeatedly.
  • 6-month-olds pay more attention to content words (nouns, verbs) than to function words (articles, prepositions).
How Infants Identify Words
  1. Stress: Languages consistently place emphasis on certain syllables in a word.
    • English: First syllable in most two-syllable nouns, adjectives, adverbs (e.g., DOUGHnut, BAsket, HAPpy).
  2. Statistics: Infants notice syllables that go together frequently (Jusczyk, 2002).
    • Example: Infants exposed to a stream of speech with specific sound combinations listened longer to new combinations, indicating they recognized the familiar patterns.
  3. Emerging knowledge of sounds in native language: Certain combinations are common, others are not.
    • "St" commonly used within words and at word boundaries.
    • "sd" is not commonly used within words, more commonly at word boundaries.
  4. Rely on “function words” (e.g., “a”, “the”) as boundaries.
    • By 6 months, infants recognize function words and use them to determine onset of words (Shi, 2014).
    • Example: "aballabataglove" becomes "a ball a bat a glove".
Infant-Directed Speech (IDS)
  • Slow, exaggerated changes in pitch and loudness.
  • Aids infants in detecting words:
    • Attracts infants’ attention.
    • Highlights vowel sounds (Kuhl et al., 1997).
    • Spoken more clearly (less mumbling).
    • Infants can segment words more effectively when listening to IDS (Thiessen, Hill, & Saffran, 2005).

Phonology: Producing Words

  • Newborns and young babies make sounds, but language-based sounds do not appear immediately.
    • Cooing: Production of vowel-like sounds such as “ooo” or “ahh”, tends to begin around 2 months old.
    • Babbling: Speech-like sounds that have no meaning.
    • 6 months: “bah” or “dah”.
    • 9 months: “bahbahbah” or “dahmahbah”.
    • Precursor to true speech.
    • Mouth movements replicate that of true speech (Holowka & Petitto, 2002).
    • Stress and sound patterns mimic those of true speech (Snow, 2006).
    • Influenced by the speech they hear (i.e., native language).
  • By first birthday, most children say their first word.
  • Common first words: Terms for mother and father (mommy, dada), greetings (Hi, bye-bye), foods and toys (juice, ball).
One-Word Stage
  • The stage in speech development, from about age 1 to 2, during which a child speaks mostly in single words.
Two-Word Stage

  • Beginning about age 2, the stage in speech development during which a child speaks mostly in two-word statements.

  • Age 2: Typically have a vocabulary of a few hundred words.

  • Age 6: Child’s vocabulary includes more than 10,000 words.

  • In the US, children tend to produce more nouns than verbs.

  • In cultures where language stresses action over objects (e.g., Korean, Chinese) the differences are less pronounced (Waxman et al., 2013).

Semantics: Understanding Meaning

  • Once children grasp that words have meaning, their rate of word-learning increases.
    • 15 months: 2-3 new words a week.
    • 18 months: 10 or more new words a week.
    • Naming Explosion.
    • Typically learn the name of objects.
    • Fast mapping: Children’s ability to connect new words to their meanings so rapidly that they cannot possibly be considering all meanings for the new world.
How Infants Learn Word Referents
  • Consider when you introduce a word, there are many plausible, yet incorrect elements a child may map the world onto.
  • Researchers believe they have uncovered distinct factors that contribute to our ability to map words onto the correct symbol.
Joint Attention
  • The focus of two individuals on an object. It is achieved when one individual alerts another to an object by means of eye-gazing, pointing, or other non-verbal indications.
  • Parents and children work together to create conditions that foster word learning:
    • Parents label objects.
    • Children rely on parents’ behavior to interpret the words they hear.
    • Children learn better when parents look at or point to the object while labeling.
    • Children consider adults’ certainty, whether they are speaking in their native language, and whether they are a “reliable” source (i.e., they learn better from credible adults).
Word Learning Constraints
  1. Whole-object constraint: A name refers to a whole object, not its parts or its relation to other objects, and refers not just to this particular object, but to all other objects of the same type.
  2. Mutual-exclusivity constraint: Bias to accept one name per object. If an unfamiliar word is heard in the presence of other objects that already have a name, the new word belongs to the object that does not yet have a name.
  3. Taxonomic constraint: Words refer to categories of similar objects.
    • Children infer that a word applied to one among many of the same category must indicate a more specific label (subcategories, proper nouns).
  • As children get older and learn more words, they can use clues from an entire sentence to determine a word’s meaning.
    • Can use the words to infer meaning. For example in the sentence "That girl is juggling the balls", a child can infer juggling is the action.
  • Toddlers know:
    • “a” and ”the” proceed nouns.
    • “he” “she” and ”they” proceed verbs.

Individual Differences in Word Learning

  • Naming Explosion typically happens around 18 months, but this timing does vary (14 months – 22 months).
  • Vocabulary range for typical 18 months: 25-250 words – variation is huge!
  • Hereditary: Twin Studies (Dionne et al., 2003) show genetics play a small roll.
  • Most important factors contributing to differences in vocabulary:
    1. Phonological Memory
    2. Child’s “language environment”.
1. Phonological Memory
  • The ability to remember speech sounds briefly.
  • Can be tested by asking a child to repeat a “nonsense” word (e.g., Ballop).
  • Children’s skill at this task is strongly related to their vocabulary.
  • Word learning involves associating meaning with an unfamiliar sequence of speech sounds.
2. Child’s Language Environment
  • #1 predictor of children’s vocabulary.
  • The more words children hear in their daily environment, the better their vocabulary.
  • Parents use different words and have sophisticated grammar.
  • Respond promptly and appropriately to child’s speech.
How to Encourage Word Learning
  • Labeling objects in daily interactions.
  • Reading books with children, especially when parents label objects of child’s attention.
  • Describing pictures and asking questions (forces children to identify meaning and practice new words).

Impact of TV/Screen Time

  • Typical preschool children in the US spend more than 2 hours a day watching some form of TV or video.
  • Programs can help with word learning.
  • Children who regularly watch Sesame Street have greater vocabular than children who only watch occasionally.
  • Programs that promote word learning:
    • Those that tell a story (e.g., Thomas the Tank Engine).
    • Those that directly ask the audience questions (e.g., Dora the Explorer).
  • Benefits are greatest when children watch alongside an adult, becoming a source of joint attention.
  • Most evidence suggests that before 18 months, infant-oriented products are not effective.
    • Many are developmentally inappropriate.
    • Infants also struggle with the understanding the relationship between images in videos and real objects—makes application difficult.

Word Learning in Bilingual Children

  • For much of the 20th century, it was believed that raising a child bilingual was harmful.
  • When children are raised bi/multilingual:
    • They pass through milestones at a similar rate (sometimes a bit slower).
    • Vocabulary for each language is smaller and overall grammar is more simplistic.
    • TOTAL vocabulary is actually higher!
  • Circumstances do relate to rate of word learning:
    • Will learn the language they hear the most at the fastest rate.
    • Will learn best/faster from a native speaker.
  • Bilingual children surpass monolingual children in some word learning tasks:
    • Better grasp that words are just arbitrary symbols.
    • More likely to understand aspects of printed word unrelated to meaning.
  • Additionally, bilingual children show improved executive functioning:
    • Better inhibitory control.