Comprehensive Notes on Communication Disorders: Language, Social, and Speech Development

Neurodevelopmental Classification of Communication Disorders

Communication disorders are classified under the broader category of Neurodevelopmental Disorders in the DSM-5 ($2013$). This category encompasses several sub-types of developmental challenges:

  • Intellectual Disabilities: Including Intellectual Disability, Global Developmental Delay, and Unspecified Intellectual Disability.

  • Communication Disorders: This specific sub-group includes:

    • Language Disorder

    • Speech Sound Disorder

    • Childhood-Onset Fluency Disorder (Stuttering)

    • Social (Pragmatic) Communication Disorder

    • Unspecified Communication Disorder

  • Autism Spectrum Disorder (ASD)

  • Attention-Deficit/Hyperactivity Disorder (ADHD): Including Other Specified and Unspecified ADHD.

  • Specific Learning Disorders: Specifically categorized by impairments in Reading, Written Expression, or Mathematics.

  • Motor Disorders: Including Developmental Coordination Disorder, Stereotypic Movement Disorder, and Tic Disorders (Tourette's, Other Specified, and Unspecified).

Language Disorder: DSM-5 Diagnostic Criteria

Language Disorder is characterized by persistent difficulties in the acquisition and use of language across various modalities (spoken, written, sign language, etc.) due to deficits in comprehension or production.

Criterion A: Symptom Description

  1. Reduced Vocabulary: Deficits in word knowledge and use.

  2. Limited Sentence Structure: Impaired ability to combine words and word endings to form sentences according to grammatical and morphological rules.

  3. Impairments in Discourse: Difficulty using vocabulary and connecting sentences to explain a topic, describe events, or engage in conversation.

Criterion B, C, and D

  • Criterion B: Language abilities are substantially and quantifiably below the expected level for the individual’s age, leading to functional limitations in communication, social participation, academic achievement, or occupational performance.

  • Criterion C: Symptoms must have an onset in the early developmental period.

  • Criterion D: The difficulties are not attributable to hearing or other sensory impairments, motor dysfunction, or medical/neurological conditions. They are also not better explained by intellectual disability or global developmental delay.

Terminology Evolution

While the DSM-5 uses "Language Disorder," many practitioners and researchers prefer the term Developmental Language Disorder (DLD). Historically, this condition was referred to as Specific Language Impairment (SLI). It represents a specific difficulty in acquiring oral language, which may be expressive (production), receptive (comprehension), or both.

Experimental Evidence and Linguistic Deficits in Language Disorder

Research has identified several core areas of difficulty for children with Language Disorder (Bishop, $1997$).

Verbatim Comparison: Narrative Ability

Bishop ($1997$) illustrates the difference between an original story and a child's version with Language Disorder:

  • Original: "Bernard walked down the steps and into the garden. When he got there, he was very surprised by what he saw. In the garden there was a purple monster, with big teeth and little horns. 'What are you doing in my garden?' said Bernard. 'I’m a monster, and I like eating little children, and I’m going to eat you up' said the monster."

  • Child’s Version: "one day Bernard went down the steps and into his garden and he- and he wa- and he shock to see a monster in his garden and him say, …what are you doing n the monster said, …I like to eat little boys, n I eat you plus that he’s a little bit bigger than Bernard."

Syntax: The "Who Did What to Whom" Deficit

Van der Lely ($1994$) investigated syntax using novel verbs like "kall." Children were asked to demonstrate sentences using toys:

  • Active: "The girl kalls the boy" (The girl toy should act on the boy toy).

  • Passive: "The girl is kalled by the boy."

  • Results: Children with SLI performed significantly worse than typically developing (TD) controls who were matched for language ability.

Morphology: Tense Marking

Children with Language Disorder often omit grammatical markers ($3$rd person singular or past tense):

  • Example: "Every day my brother walk to school" or "Yesterday I walk to school."

  • Study by van der Lely & Ullman ($2001$): Compared children with SLI (aged $9$-$12$) against TD children (aged $6$, $7$, and $8$).

  • Stimuli:

    • Irregular verbs (give-gave)

    • Regular verbs (rob-robbed)

    • Novel irregular (crive-crove)

    • Novel regular (brop-bropped)

  • Findings: For novel regular verbs (e.g., "bropped"), children with SLI achieved approximately $30.0\%$ accuracy, significantly lower than the $70.0\%$ to $80.0\%$ accuracy seen in $8$-year-old TD children.

Phonology and Vocabulary

  • Snowling et al. ($2019$): A longitudinal study from ages $3$ to $8$ found that phonological deficits are strong predictors of later language difficulties, though these often improve over time. The study tracked children with family risks of dyslexia and language impairment, finding significant overlap (comorbidity) between dyslexia and DLD.

  • Gathercole & Baddeley ($1990$): Used nonword repetition tasks (e.g., repeating "blay" or "thickery"). Children with language disorder struggled significantly more with multisyllabic nonwords compared to language-matched and nonverbal IQ-matched controls. On single-syllable nonwords, children with language disorder scored near $35$ correct responses, but this dropped drastically to below $15$ for multisyllabic nonwords.

Aetiology of Language Disorder

There are three primary theoretical accounts for the origins of Language Disorder:

  1. Genetic/Innate Foundations:

    • Twin studies (Tomblin & Buckwalter, $1998$; Bishop et al., $1995$) show a strong genetic contribution.

    • Specific Linguistic Theories: Suggest a deficit in an innate grammatical mechanism. This is supported by the case study of AZ, who exhibited a grammar-specific impairment (van der Lely et al., $1998$).

  2. Cognitive Theories:

    • Propose a working memory impairment, specifically in the phonological loop (Gathercole & Baddeley, $1990$).

    • Archibald & Gathercole ($2007$) noted the deficit is more pronounced for nonwords than real words, explaining why word learning is specifically difficult in SLI.

  3. Perceptual Theories:

    • Tallal et al. ($1996$) suggested a deficit in the auditory perception of rapid speech sounds.

    • Research showed that training with acoustically enhanced speech (processed to be slower and louder) improved speech discrimination, language processing, and grammatical comprehension.

Social (Pragmatic) Communication Disorder (SCD)

SCD is a focus on the social use of communication rather than the structural components (grammar/vocabulary).

DSM-5 Criteria A: Deficits in Social Communication

  1. Social Purposes: Deficits in using communication for greetings or sharing information appropriately for the context.

  2. Context Matching: Inability to change communication to match the listener or setting (e.g., talking to a child vs. an adult; classroom vs. playground).

  3. Conversational Rules: Difficulty with turn-taking, rephrasing when misunderstood, and using verbal/nonverbal signals.

  4. Inference and Non-literal Language: Difficulty understanding idioms, humor, metaphors, or meanings that are not explicitly stated.

DSM-5 Criteria B, C, and D

  • Criterion B: Leads to functional limitations in relationships, social participation, or academic/occupational performance.

  • Criterion C: Early onset (though may not manifest fully until social demands increase).

  • Criterion D: Not attributable to other medical conditions, low grammar/word structure skills, ASD, or intellectual disability.

Distinguishing SCD from Other Disorders

SCD was identified by Rapin and Allen ($1987$) as children who were often not recognized as language-impaired but seen as "bizarre." Previously categorized as a subtype of SLI (Pragmatic Language Impairment), it is now a distinct diagnosis.

Conti-Ramsden et al. ($1997$) Findings

A study of $242$ children with SLI aged $7$ identified a cluster of children with semantic/pragmatic difficulties who:

  • Had only receptive problems without phonological difficulties.

  • Performed well on most standardized tests (e.g., Raven’s Matrices, Naming Vocabulary) but were flagged by teachers/therapists as having substantial real-world language difficulties.

Assessment via the Children’s Communication Checklist (CCC)

Bishop ($1998$) utilizes $5$ subscales for pragmatic use:

  1. Inappropriate initiation (e.g., sudden topic changes).

  2. Coherence.

  3. Stereotyped conversation.

  4. Use of context.

  5. Rapport. Rapin and Allen ($1987$) described these children as having "very fluent expressive language, but language is often not really communicative."

Inferencing Research: Norbury & Bishop ($2002$)

This study compared children aged $6$-$10$ with PLI/SCD, SLI/DLD, and Autism using an experimental inferencing task.

Sample Story: "Debbie and Michael"

"Debbie was going out for the afternoon with her friend Michael. By the time they got there they were very thirsty. Michael got some drink out of his bag and they shared that. The orange juice was very refreshing. Debbie put on her swimming costume but the water was too cold to paddle in, so they made sandcastles instead. They played all afternoon and didn’t notice how late it was. Then Debbie spotted the clock on the pier. If she was late for dinner her parents would be angry. They quickly packed up their things. Debbie changed and wrapped her swimming costume in her towel. She put the bundle in her rucksack. Then they set off for home, pedalling as fast as they could. Debbie was very tired when she got home, but she was just in time for dinner."

Inference Types Tested

  • Literal: "Who did Debbie spend the afternoon with?" (Michael). "Where was the clock?" (On the pier).

  • Text-connecting: "Where did Michael get the orange juice?" (His bag). "Where did Debbie put her towel?" (In her rucksack).

  • Gap-filling: "Where did Debbie and Michael spend the afternoon?" (The beach). "How did they travel home?" (Bicycles/pedalling).

Results: Proportion of Groups with Very Low Scores

  • Control: $6\%$

  • SLI: $25\%$

  • PLI (SCD): $33\%$

  • Autism: $50\%$

While many children with SCD have difficulty with inferences, patterns of difficulty often overlap across different language impairments. SCD is frequently comorbid with ADHD, social anxiety, and behavioral difficulties (Ketelaars et al., $2010$).

Speech Sound Disorder and Childhood Onset Fluency Disorder

Speech Sound Disorder (DSM-5)

  1. Persistent difficulty with speech sound production interfering with intelligibility or verbal communication.

  2. Causes limitations in social, academic, or occupational performance.

  3. Early onset.

  4. Not attributable to conditions like cerebral palsy, cleft palate, or hearing loss.

Childhood Onset Fluency Disorder (Stuttering) (DSM-5)

  1. Disturbance in normal fluency/time patterning of speech characterized by:

    • Sound/syllable repetitions.

    • Sound prolongations (consonants/vowels).

    • Broken words (pauses within words).

    • Audible or silent blocking.

    • Circumlocutions (word substitutions to avoid hard words).

    • Excess physical tension during word production.

    • Monosyllabic whole-word repetitions (e.g., "I-I-I-I see him").

  2. Causes anxiety about speaking.

  3. Early onset.

  4. Not attributable to neurological insult (stroke/trauma) or speech-motor/sensory deficits.

Potential Exam Case Study: Muhammad

Case Profile:

  • Name: Muhammad, $7$ years old.

  • History: Full-term, no neonatal concerns, passed hearing screenings at birth and age $5$. No medical history of seizures or hospitalizations. No known history of ASD or ID.

  • Symptoms: Difficulty following multi-step directions, limited vocabulary, frequent grammatical errors, struggles with retelling stories, and reliance on gestures.

Analysis Requirements:

  1. Diagnosis: Likely Developmental Language Disorder (DLD).

  2. Cognitive Basis: Discussion of working memory/phonological loop deficits (Gathercole & Baddeley) vs. innate grammatical mechanism deficits (van der Lely).

  3. Exclusions: Can rule out Speech Sound Disorder (no mention of intelligibility issues), Fluency Disorder (no stuttering noted), and SCD (symptoms emphasize grammar and vocabulary rather than just social pragmatics).

  4. Parental Support: Interventions for infants like Maya (Muhammad's $1$-month-old sister) to support language development.

  5. Lay Summary: A $200$-word explanation for the parents regarding the diagnosis and underlying mechanisms.