Language Acquisition and Disorders

Overview of Communication and Language

• Definition of Communication: Communication is the exchange of information. It is the process of one person having information and giving it to another. This can occur with or without the use of language.

  • Non-Linguistic Communication: Communication happens in the absence of language in various contexts:

    • Animals communicate with each other.

    • Computers communicate with each other.

    • Human methods include speech, signs, gestures, pictures, dance, and music.

• Definition of Language: For a system to be considered a language, it must have a shared system of codes that represent other things.

  • Shared System: A language must have a set of users who all know and understand the same code to use it together.

  • Linguistic Perspective: Language is a cognitive system of rules.

  • Behavioral Perspective: Language is shaped by a community; it is only meaningful if shared.

• Core Concepts: Language is distinct from voice. Voice involves resonance and respiration (the physical creation of sound), whereas language is primarily a cognitive process.

Theories of Language Acquisition

• Nativist Theory (Noam Chomsky):

  • Suggests that people are born with a Language Acquisition Device (LAD), an innate part of the brain containing the ability to learn language without direct instruction.

  • Supports the idea that babies can learn any language they are exposed to regardless of which specific one it is.

• Cognitive Theory (Jean Piaget):

  • Proposes that language development is based on brain development.

  • Contends that an individual must be able to think before they can learn language.

  • Debate on Cognition vs. Language: There is ongoing debate regarding whether cognition comes first or if language is required to provide a way to think (e.g., thinking in pictures vs. language).

• Behavioral Theory (B.F. Skinner):

  • Language is a behavior acquired socially through conditioning and interaction.

  • Argues language is learned rather than innate.

  • Evidence from Deprivation: Skinner supported this by noting that a lack of language access leads to deficits.

  • Case Study: Genie (The "Wild Girl"): An abused child locked in a closet until age 13. Because she was never spoken to, she lacked functional language. Despite later intervention and placement in a home, she never achieved the linguistic level of a typically developing $13$ or $14$ year old, illustrating the necessity of early stimulation.

• Social Theory (Lev Vygotsky):

  • Language development is dependent on social interaction and the "social give and take."

  • Mother-Child Interaction Studies: Research shows that parents are "hardwired" to attend to baby babbling. When a baby says something like "Mama," the parent responds with excitement, reinforcing the behavior and driving language development.

• Language Deprivation in Deaf/Hard of Hearing Children: If children cannot hear and do not have fluent signing parents providing visual language models, they can fall behind due to a lack of language input.

Key Features and Components of Language

• Generative Nature of Language: We can combine words and phrases to create an infinite number of unique utterances. Children do not learn every possible sentence; they learn rules for how words are formed and combined.

  • Example Sentence: "Large pink elephants danced gracefully under the streetlights."

  • Even if a person has never heard this specific string of words, they understand it because they know the meaning of individual words and the rules for combining them.

• Receptive vs. Expressive Language:

  • Expressive Language: The language we produce (speaking/signing).

  • Receptive Language: The language we receive and understand.

  • Ratio: Generally, language comprehension exceeds production by a ratio of $4$ to $1$. A student might understand $40,000$ words but only use $10,000$ regularly.

• Phonology: The rules governing the structure, distribution, and sequence of speech sounds (phonemes).

  • Phonemes: The smallest meaningful units of sound that can change the meaning of a word.

  • English Statistics: English has $46$ phonemes but only $26$ graphemes (written letters).

  • Sequencing Rules: Every language has specific rules. In English, the "ng" sound never appears at the beginning of a word. There are no words where "d" and "n" appear together without a vowel between them.

  • Voicing Influences: In the word "jogged," the final sound is a voiced "d" ($jogged$) because of the voiced "g." In "walked," the final sound is an unvoiced "t" ($walkt$) because "k" is unvoiced. Similarly, the "s" in "dogs" sounds like a "z."

• Morphology: The organization of sounds into words and word parts.

  • Morpheme: The smallest meaningful grammatical unit.

  • Free Morpheme: Can stand alone as a word (e.g., "bird").

  • Bound Morpheme: Must be attached to a free morpheme (e.g., the plural "s").

  • Derivational Morphemes: Change the grammatical category of the word (e.g., "govern" [verb] + "ment" = "government" [noun]; "happy" [adjective] + "ly" = "happily" [adverb]).

  • Inflectional Morphemes: Provide grammatical information without changing the category (e.g., "ed" for past tense, "s" for plural).

• Syntax: The rules for ordering words to make sentences.

  • Adjective Order in English: There is an innate, unwritten rule for adjective sequencing: Opinion, size, physical quality, shape, age, color, origin, material, type, purpose (e.g., "A wonderful big black metal fishing boat").

• Semantics: The literal meaning of words and phrases. Developing semantic knowledge require prior world/background knowledge.

• Pragmatics: Social rules for using language in context.

  • Includes turn-taking, topic maintenance, and understanding the listener's perspective.

  • Non-literal Meaning Example: "Could you pass the salt?" is pragmatically a polite request, not just a yes/no question about physical ability.

  • Indirect Requests: A four-year-old asking "Are those pickles?" might actually be indirectly asking for a pickle.

  • Disorders: Autism Spectrum Disorder (ASD) often involves difficulty following prescribed pragmatic rules.

Language Development Timeline

• Newborns: Produce reflexive cries without intent. They lack object permanence (the understanding that things still exist when out of sight) until approximately $6$ to $9$ months.

• $2$ Months: Quasi-resonant nuclei emerge (vowel-like gurgling sounds with slight constriction).

• $4$ to $6$ Months: Canonical babbling (reduplicated consonant-vowel sounds like "ba ba ba").

• $8$ to $12$ Months: Development of communicative intent (pointing, reaching, showing). Joint attention begins (sharing interest in an object with another person).

• $9$ to $10$ Months: Variegated babbling or jargon begins (combining different sounds).

• $9$ to $12$ Months: Emergence of language comprehension.

• $12$ Months: Average age for the first word (typical range is $10$ to $18$ months).

• $18$ Months: Vocabulary reaches approximately $50$ words; two-word combinations begin.

• $2$ Years: Expressive vocabulary of $200$ to $300$ words; grammatical morphemes emerge; conversational turn-taking begins.

• $3$ Years: Talking in $3$ to $4$ word sentences; talks mostly about the present.

• $4$ Years: Asks many questions (including "why"); tells stories; uses complex language forms.

• $5$ Years: $90\%$ of grammar acquisition is complete; can discuss feelings and things not physically present (past/future).

• High School Graduation: Comprehension of upwards of $80,000$ words.

Language Disorders

• Etiologies: Genetic syndromes, intellectual disability, hearing loss, autism, environmental factors, birth defects, or neurological impairments.

• Developmental Language Disorder (DLD): Formerly called Specific Language Impairment (SLI). A language disorder with no known etiology (cannot be pinpointed to a specific syndrome or medical event).

• Classification:

  • Receptive: Impairment in understanding language.

  • Expressive: Impairment in producing language.

  • Pragmatic: Impairment in social usage.

  • Syntactic: Difficulty with grammar and sentence structure.

Assessment and Treatment by SLPs

• The Clinical Process:

  1. Determine if a disorder exists.

  2. Identify the nature and severity.

  3. Develop a plan for help.

• Evaluation Components:

  • Case History/Interview: Milestones, medical history, family history, and academic history.

  • Screenings: Every evaluation includes a hearing screening and an oral mechanism exam. Language screenings are often done in schools (e.g., first graders).

  • Observation: Informal play (young children) or parent-child interaction.

  • Standardized Tests: Norm-referenced tests providing standard scores (often required by insurance).

    • Preschool Language Scale (PLS-5): Uses manipulatives (bears, bowls, blocks) for ages birth to $7$.

    • OWLS-2: Picture-based test for ages $4$ to $21$.

    • PPVT: Tests vocabulary only by having patients point to pictures.

  • Language Sampling: Naturalistic collection of connected speech to analyze Mean Length of Utterance (MLU), pragmatics, and comprehension.

• Treatment Strategies:

  • Modeling: Providing an example for the child to imitate.

  • Positive Reinforcement: Rewarding correct responses.

  • Expanding: Repeating a child's utterance but adding more information (e.g., child says "car," SLP says "blue car").

  • Incidental Learning: Picking up skills naturally.

  • Generalization: Ensuring skills learned in the therapy room are used in the natural environment.

  • Family-Centered Model: Best practice for early intervention involves coaching the caregiver on how to interact and provide feedback at home.

Literacy and the SLP Scope of Practice

• Definitions: Reading is making sense of symbols; writing is putting symbols on a page to create meaning.

• ASHA Position (2001): Assessment and treatment of literacy skills are within the SLP scope of practice.

• Emergent Literacy Categories:

  • Print Awareness: Holding a book correctly, moving fingers left to right, scribbling.

  • Alphabet Knowledge: Naming and printing letters.

  • Phonological Awareness: Detecting syllables/rhymes and manipulating sounds (segmenting and blending sounds, e.g., saying "cat" without the "c").

• The Third Grade Shift: Until third grade, children "learn to read"; after third grade, they "read to learn."

• Cultural Responsivity in Literacy: Dialects (e.g., Southern accents) can influence spelling. For example, a child might not distinguish between "pin" and "pen" or might leave the "g" off "fishing" (spelling it "fishin"). These are reflections of linguistic difference, not necessarily a disorder. ASHA maintains that no dialect is superior to another.

Questions & Discussion

• Q: Does hearing loss cause language delay?

  • A: Strictly speaking, no. Hearing loss does not cause delay, but a lack of access to language does. Deaf children with deaf parents who use American Sign Language (ASL) from birth have language skills on par with hearing peers.

• Q: When is it impossible to spoil a baby?

  • A: Until about $6$ to $9$ months, babies do not have the cognitive ability for manipulation because they lack object permanence. They cry as a reflex to a need, not to manipulate the caregiver.

• Q: What is the relationship between language and literacy disorders?

  • A: Approximately $60\%$ of kids with language disorders will also have a literacy disorder, as poor oral language skills often translate to struggles with written language.