1 Infancy

Infancy

  • Refers to the first year (12 months) of life.

Language Development during Infancy

  • Expressive Language: Very little expressive language.

  • Receptive Language: Skills blossom; infants are constantly exploring and learning.

Studying Infant Language

  • Habituation-Dishabituation: Repeated presentations of the same item, followed by a change to see how the child responds.

  • Switch Task: Present two objects together, then change the order of presentation, used in conjunction with habituation-dishabituation.

  • Intermodal Preferential Looking Paradigm: Observes if the child looks at the visual matching the audio.

  • Naturalistic Observation: Involves observing infants in their natural environment.

Receptive Milestones

  • Tracking these milestones helps assess infant development in understanding language.

Infant Speech Perception

  • Infants notice patterns in speech using statistical learning.

  • Perceptual Narrowing: Younger children can discriminate phonemes across languages, but as they grow, they focus on their native language.

Prosodic Regularities

  • Intonation: Variation in vocal pitch that alters sentence meaning (e.g. "do you like monkeys?" vs. "DO you like monkeys?").

  • Stress: Emphasis on certain syllables. Prosody combines frequency, duration, and intensity of sound.

  • By 9 months, infants prefer familiar stress patterns from their native language, aiding word isolation.

Phonetic Regularities

  • Infants pay attention to phonetic details, which helps segment speech into words and phrases through phonotactic regularities.

Categorical Perception

  • Ability to categorize sounds effectively, distinguishing speech and non-speech sounds.

  • Infants categorize speech sounds into meaningful phonemes based on voice-onset time (VOT). Notably strong in consonants but less so in vowels.

Awareness of Intentions

  • Around 4 months, infants can discern between intentional vs. accidental actions. They notice goal-directed actions by attending longer to changes in goals.

Category Formation

  • Infants can visually distinguish animals (e.g., cats vs. dogs) by 3 months.

  • Perceptual Categories: Based on outward features (color, shape).

  • Conceptual Categories: Based on knowledge of object functions, develops later.

Semantic Category Formation

  • Categories develop hierarchically:

    • Superordinate: Large categories (e.g., Furniture)

    • Basic: General concepts (e.g., Rug)

    • Subordinate: Specific items (e.g., Bathmat).

  • This categorization predicts cognitive and linguistic abilities at 2 years old.

Expressive Milestones

  • Understanding vocalizations and their effects on communication is key in early development.

Early Vocalizations

  • Infants learn vocalizations can elicit reactions from others, starting with non-cry vocalizations by 5 months to convey messages.

Development of Vocalizations

  • Classified into Stark Assessment of Early Vocal Development-Revised (SAEVD-R) with 23 types of vocalizations across 5 levels of development.

Vocal Stages

  • Stage 0 (0-2 months): Reflexive sounds (crying, vegetative sounds) with no communicative intent.

  • Stage 1 (1-4 months): Exploration of voice, producing cooing, laughter, and consonant-like segments.

  • Stage 2 (3-8 months): Increased control leads to experimentation with pitch and loudness with marginal babbling.

  • Stage 3 (5-10 months): Development of canonical babbling with multiple CV syllables (e.g., "babababa"). Deaf infants will babble with hands if exposed to sign language.

  • Stage 4 (9-18 months): Advanced forms emerge with more complex syllable structures and jargon resembling real words.