DLD is often a hidden disability, not easily noticeable like speech sound disorder (SSD).
It affects language comprehension and production.
A family history suggests a genetic component to DLD.
DLD can be overlooked, with the misconception that children will outgrow it.
Individuals with DLD may be accused of academic dishonesty due to grammar errors and writing style that lacks morphemes. Professor might think a student is non-native English speaker due to writing style.
Symptoms of DLD can overlap with characteristics of bilingual children learning English, making diagnosis complex, especially in multilingual areas.
Individuals with DLD develop compensatory strategies to manage daily life, such as preparing scripts for social interactions.
Many individuals with DLD go undiagnosed, and explaining the condition can be challenging due to lack of awareness.
Learning Outcomes
Define DLD and describe its typical symptoms.
Understand the longer-term consequences of DLD.
Recognize the persistence of DLD issues throughout life.
Definition of DLD
DLD is a lifelong condition, similar to ASD and ADHD.
It involves persistent problems with language acquisition and use.
Two broad groups:
Language problems due to identifiable biomedical conditions (e.g., hearing loss, brain injury): language disorder.
Language problems with no identifiable cause: requires further assessment and may be DLD.
Developmental Language Disorder (DLD): Persistent difficulties in language development without a clear biomedical etiology, resulting in functional impairment.
Functional impairment: Real-life consequences that hinder participation in society.
Three Components of DLD Definition
Persistence: Difficulties are not transient but continue throughout life.
No Clear Biomedical Etiology: Not caused by conditions like hearing loss or brain injury.
Functional Impairment: Impacts daily functioning and participation in society.
Conceptualizing DLD
Analogous to clinical depression: Low language skills alone do not indicate DLD, just as sadness doesn't always mean clinical depression. It is the persistence and detrimental impact on daily functioning that leads to a diagnosis.
Speech, Language, and Communication Needs (SLCN)
SLCN is a broader category in education settings for kids needing extra support.
Includes:
Lack of familiarity with ambient language (e.g., English as a second language, dialectal differences).
Speech Sound Disorder (SSD).
DLD.
Language Disorder (associated with biomedical etiology).
Fluency disorders (e.g., stuttering).
Major Symptoms of DLD by Age Group
1-2 years: No babbling, not responding to speech and sounds, minimal attempts to communicate.
5+ years: Difficulties identifying DLD before age 5 due to dynamic developmental changes.
Language Skill Development
Language skills can vary significantly from 8 months to 4 years.
Some children start with advanced skills that normalize over time.
Others start behind but catch up.
Some remain consistently average.
Some start average but fall behind, indicating a potential issue.
Identifying DLD before age 5 is challenging but not impossible.
Difficulties at age 5 are likely to persist.
Vocabulary Development
Vocabulary scores:
Typically developing children: Scores increase with age.
Children with DLD: Scores increase, but the gap with typically developing children persists.
Children with language disorder (biomedical condition): Similar pattern to DLD.
Prevalence of DLD
DLD has a high prevalence (7%), often higher than other developmental conditions.
In a classroom of 30, approximately 2 students have DLD.
Hallmark symptom is the persistence of language difficulties.
Individuals with DLD may have been perceived as academically weak, shy, bullied, or class clowns.
Language Symptoms of DLD
Morphological Impairment
Problems with inflectional grammar (tense, aspect).
Omission errors are frequent and persistent.
Examples: Agreement, singular person, past tense morphemes.
Most studied but may not be the most critical issue for individuals with DLD.
Syntactic Impairment
Difficulties with complex sentences, relative clauses, and embedded clauses.
Inefficient communication.
Tendency to break down complex sentences into simpler ones.
Lexical Semantics (Vocabulary)
Use of non-specific terms like "thing" and "stuff."
Contextual understanding may mask language deficits.
Detailed language analysis reveals limited vocabulary.
Discourse
Narratives may lack coherence; individuals may go off on tangents and not complete thoughts.
Engage in communication but lack adequate language skills.
Quick topic shifts to avoid comprehension difficulties.
Hidden disability: Difficulties are not always apparent.
Non-Language Symptoms of DLD
Motor coordination problems (clumsiness, difficulty with motor tasks).
Delays in symbolic play (reflection of cognitive development).
Executive function deficits (attention, memory).
Socio-emotional difficulties:
Increased emotional, behavioral, and ADHD-like symptoms.
Alexithymia: Difficulty identifying and describing emotional states in oneself, leading to emotional dysregulation.
Why Non-Language Symptoms?
Language as a Tool: Language difficulties affect various life aspects, leading to socio-emotional problems.
Underlying Impairment: Non-language symptoms may be part of the core symptomatology of DLD, with an underlying impairment affecting language, motor coordination, and socio-emotional aspects.
Theoretical Stances
Modular Approach: The human mind has separate modules for language, math, memory, etc. DLD is an impairment in the language module causing secondary issues.
Domain-General Approach: Mental architecture is broad and abstract. Attention, memory, and language result from domain-general skills working together.
Ascertainment Bias: Research participants are often recruited from clinical settings, which may include individuals who are more severely affected with co-occurring conditions.
Procedural Deficit Hypothesis: Impairment in the procedural memory system is responsible for both language and non-language symptoms.
Long-Term Consequences of DLD
DLD manifests differently across individuals.
Presentations vary: withdrawn/shy or outgoing/disruptive.
Long-term consequences are increasingly recognized, emphasizing DLD as a lifelong disability.
Symptoms may not be apparent before age 5, leading to misdiagnosis or lack of recognition.
Lack of universal screening for language conditions in Australia.
Significant lack of services for adults with DLD.
Reading Comprehension Problems
Simple View of Reading: Reading comprehension is the product of accurate word recognition (decoding) and spoken language comprehension. \text{Reading Comprehension} = \text{Decoding} \times \text{Spoken Language Comprehension}
If either decoding or language comprehension is zero, reading comprehension is zero.
Four Quadrant Model of Reading Difficulties
Skilled Readers: Good decoding and language comprehension.
Poor Reading Accuracy (Dyslexia): Good language comprehension but poor decoding.
Poor Reading Comprehension: Good decoding but poor language comprehension (majority of kids with DLD).
Mixed Condition: Difficulties in both decoding and language comprehension.
Reading is a linguistic task, so language comprehension difficulty translates to reading comprehension difficulty.
Consequences in School
Increased demand for literacy throughout school years.
Lower grades, remedial support, subject failure, dropout, and less likely to pursue higher education.
Difficulties extend to dating and romantic relationships.
Inadequate language skills hinder communication and relationship building.
Participation in Education
Lack of linguistic resources to understand instructions and ask for help.
Perceived as having antisocial behaviors due to language limitations.
Trouble with authority figures and being misunderstood.
Often referred to educational psychologists instead of speech pathologists, leading to ineffective interventions.
Beyond School Years
Achieving Independence
Fundamental task in adolescence with severe costs for failure.
Difficulties in tasks like using a telephone or going out with friends, managing money, having a job.
Difficulty obtaining a driver's license due to reading comprehension issues affects independence.
Employment
Not necessarily difficulty getting employed, but more likely to be in part-time employment or jobs not requiring higher education.
Difficulties participating in office politics and social aspects of work.
Lower income bracket and job dissatisfaction.
Trend towards jobs requiring strong communication skills creates barriers for individuals with DLD.
Social Exclusion
Prolonged unemployment, lack of friends, and romantic relationships leading to social exclusion.
Dependence on parents and government benefits.
Involvement with the Justice System
High rates of communication difficulties among incarcerated youth (60-90%).
Difficulties conforming to legal instructions and participating in court proceedings.
Cycle of trouble due to language impairment, both getting into and out of it.
Inability to understand legal language and express remorse.
Matthew Effect
The richer get richer; early advantages lead to exponential growth.
Reverse Matthew Effect: Initial disadvantages worsen over time.
Typically developing kids acquire language easily, enjoy learning, and participate in class, creating a positive cycle.
Kids with DLD struggle with reading, avoid learning, and disengage from school, creating a negative cycle.
Functional Demand vs. Skills
Biological maturation occurs naturally.
Functional demand (e.g., reading, math) is required by society.
School entrance marks the point where functional demand exceeds current skills.
Teachers help bridge the gap between skills and demand.
Individuals with DLD start with lower skills and the system isn't set up to help them catch up.
Emphasis on early intervention to minimize negative consequences.
Need for resources to support adolescents and adults with DLD, not just early intervention.
Concerns about neurodiversity movement potentially overshadowing DLD support because resources tend to all go to supporting individuals with ASD and ADHD.