Specific Language Impairment

Question 1

What is specific language impairment?

Name 4 key characteristics and the prevelance

Answer 1

language difficulties that create barriers to communication or learning in everyday life
Persistent across development
Not associated with a known biomedical condition
Language not usual time-course
Typical development in other areas
About 10% of population, more common in boys

Question 2

Why use DLD not SLI?

Answer 2

SLI children with language difficulty were excluded from treatment including 
	social disadvantage 
	bilingual 
	learning difficulties 
	Otis media (‘glue ear’) 
	ASD

Question 3

Why is DLD like dyslexia?

Answer 3

 Affect language, reading, spelling, writing, phonology
 Emerge in early life and persist across the lifespan
 Heritable
 Greater prevalence in boys
 Differences in brain imaging studies
 Not related to IQ

Question 4

Why is DLD not like dyslexia?

Answer 4

 DSM5 neurodevelopmental disorders:
• Dyslexia = specific learning disorder;
• DLD = communication disorder

Question 5

Tests for DLD?

Answer 5

o Speech and Language Therapist interview
o Clinical Evaluation of Language Fundamentals
o Children’s Communication Checklist (CCC-2)
o Test for Reception of Grammar (TROG-2)
o Picture vocabulary test
o IQ test
o Test for ADHD, ASD, Dyslexia, consider bilingualism

Question 6

Slow talking as a symptom

Answer 6

o Late talkers –lowest 10% in terms of productive vocabulary at age 2 years
o 40% of late talkers at age 2 will be diagnosed with language impairment by age 6 or 7
o Most “catch up
 at the lower end of the normal distribution
o Slow vocabulary development–also predictor of Dyslexia

Question 7

What area is reduced in DLD?

What area is atypically lateralised?

Answer 7

o Reduction in Superior Temporal Gyrus

o Atypical lateralisation in Inferior Frontal Gyrus

Question 8

Heritability of DLD depends on?

Answer 8

• Age of diagnosis
persistent language delay is more heritable
• Diagnostic criteria
Lowest 10% language scores vs parental referral
Parental referral is related to higher heritability

Question 9

Rates of DLD in MZ DZ and overall?

Answer 9

• Monozygotic = .90
• Dizygotic = .33
• Heritability = .64

Question 10

GWAS studies identified which two genes in DLD?

Answer 10

 Mutations in the FOXP2 gene
• Result in speech and language issues
 CNTNAP2 variants affect early language development in the general population. (also autism)

Question 11

Give two general explanations of DLD

Answer 11

o rapid auditory processing deficit
 brains have difficulty perceiving rapidly successive acoustic changes
• Finger tapping (speed and alternation) impaired
• Motor and timing deficits, clumsy (common in cerebellar damage)
 Fastforword is treatment based on this

o Procedural learning
 Lead to issues with learning phonology and grammatical rules
 Learning is automatic / unconscious
 Rule learning