8>Language impairments Flashcards
outdated perspectives on language acquisition>
- every child acquires language in the end
- as an automatic process & innate
Current knowledge of lang acquisiton>
- in Uk now more than 1.4 mill children with speech, lang & communication needs
- more than 10% of UK children have some problems acquiring/using lang in everyday settings/domains
What percentage of children does DLD affect?>
- 7.5 % of all english speaking children
why is DLD called ‘the most common childhood condition you’ve never heard of’? (4)
- as often goes unnoticed for a long time
- unlike ADHD/autism, doesnt have clear symptoms (many children mask)
- might not include problems with pronunciation, may just understand complex lang later
- might come across as ‘shy’
Why should we be concerned about lang learning difficulties?>
- only 20.3% of pupils with SLCN gained grade 4/C or above in english & maths at GCSE compared to 69% of all pupils
- children with poor vocabulary skills are twice as likely to be unemployed when reach adulthood
- high emotional cost (stressful)
- can cause struggle to form relationships
- DLS common among young offenders
what to do with case that you think might be DLD?>
- use NHS link for referral
- as parent–>go through GP; they will refer a speech & lang therapist
- in school/nurseries–>forms to fill in; dont have to wait for parents if they seem to not be doing anything
Diagnosing DLD process> (once referred)
- FIRST: need to exclude possibility eng struggles are due to bilingualism
- SECOND: need to exclude BIOMEDICAL causes
- AlSO: need to check hearing (if temporary can cause temporary problems)
Diagnosing DLD process> Step 1:
- need to exclude possibilty eng struggle are due to bilingualism
- bilinguals tend to have smaller vocabularies in single lang, thus can appear similar to DLD
diagnosing DLD> step 2:
need to exclude biomedical causes
-i.e. could disorder be explained by Down’s syndrome/other disorder
- found DLD often co-occurs with other disorders (thus want to understand if disorder is on own or if other factors involved)
Traditionally how is DLD characterised?>
-by language deficits in the ABSENCE of any clear biomedical cause (such as the chromosome abnormality seen in down’s)
why is the label DLD recommended?>
1> labels like ‘developmental aphasia’ implies parallels with adult acquired deficits (<these caused usually by a stroke, so quite different)
2> problems observed are not specific to lang (as SLI implies)
Which aspects of language does DLD affect?>
(ALL)
- phonology
- word learning
- grammar
- pragmatics
DLD & problems with phonology (2)
- difficulties perceiving, storing & producing speech segments
- deficits in phoneme constancy
how to test DLD phonological difficulties with perceiving storing and producing speech segments> (3)
give a new word to them> see if can imitate word> see if can re-produce 5 mins later
DLD & problems with phonology> deficits in phoneme constance>
-problems with knowledge of sound categories
(e.g. treating the /t/ in ‘cat’ & ‘tap’ as different phonemes & not seeing commonality between two)
DLD & problems with word learning> (2)
- require more exposure to learn new words & retention is poor
- have a underdeveloped knowledge of word meanings
DLD & problems with word learning> study (meaningful/non-meaningful words)
- played sentences to kids with & kids without DLD
- presented words in meaningful vs non-meaningful phrases “eat the bread” vs “eat the bed”
DLD & problems with word learning> study (meaningful/non-meaningful words)>results:
- only kids without DLD showed an EEG response to nonsensical sentence “eat the bed”
- kids with DLD either didnt show a response, or less likely to show EEG response to nonsensical “eat the bed”
^thus clear processing word meanings in different ways
DLD & problems with grammar> (4)
- missing inflections (“he like chocolate”)
- object/sub pronoun errors (“her sleeping”)
- tense errors (“yesterday i goed beach”)
- less generalisation
(i.e. worse at WUG where have to show creativity> also problems with converting passive>active)
DLD & problems with pragmatics> (4)
- higher rate of non-verbal responses
- tangential or ‘wandering’ answers (‘over-informative’)
- poor discourse-level understanding, despite understanding of constituent sentences
- poor understanding of jokes, figurative lang, idioms & metaphors, potentially attributable to lexical deficits
problems with pragmatics> DLD vs autism>
- suggestion that this is what differs between DLD & autistic kids
- autistic–>general misunderstanding of figurative lang
- DLD–>caused by underlying problems with lexical knowledge
DLD & comorbidity>
- comorbidity as norm
-DLD can cooccur with: motor control deficits (dyspraxia, dysarthria); ADHD; dyslexia; autism
evidence for ‘delay’ theory of DLD>
- many deficits (e.g. in word learning) seen in DLD disappear when children get older
evidence for ‘deviance’ theory of DLD>
- children with DLD produce a higher rate of bare stems (“he like tennis”) than younger children
How to do clinical assessment of DLD>
- step 1: use ‘standardised assessment kit’
- step 2: tailored intervention by trained SLT (speech & lang therapist)
clinical assessment of DLD> step 1: standardised assessment kit (3)
- this as clinical evaluation of language fundamentals
- ^these include: word classes, sentence comprehension, following direction, pragmatic understanding
- have different kits for different age ranges
clinical assessment of DLD> step 2: tailored intervention by trained SLT>
- this as based on areas of weakness identified during clinical assessment
clinical assessment of DLD> step 2: tailored intervention by trained SLT> e.g. for phonological problems>
- for initial/medial sounds–> given words/images & asked to find words with similar sounds
- for rhyming pairs–>given words/images & asked to identify rhyming pairs
clinical assessment of DLD> step 2: tailored intervention by trained SLT> e.g. for syntactic problems>
- use of different colours & shapes to show how phrases can move around & illustrate constituent structure of sentences
(e.g. Ns in red; DETs in pink; V/aux in blue)
Problems with determining which programs of intervention work & which do not>
- some people cagey about methods (/down to intuition)
- not clear if same types of procedure/interventions are useful
What are 2 types of causes DLD?>
1>proximal causes (e.g. cognitive deficits)
2>distal causes (e.g. environment, genetics, neurobiology)
Proximal causes of DLD>
- working memory capacity limitation (remembering & manipulating info)
- auditory processing deficit
- sequence learning deficit
Proximal causes of DLD> how can test working memory limation>
- giving a sequence of digits & asking to repeat in reverse order (remembering & manipulating info)
Proximal casues of DLD> sequence learning deficit>
- dont remember sequences/order of words (& also other items i.e. coloured blocks)
why is it difficult to determine WHERE problem lies with proximal causes of DLD?>
- 3 causes partly interrleated
- e.g. working memory & auditory processing both are related to ‘fuzziness’ around words (in 1st difficult to remember word due to poor working memory> fuzziness; in 2nd ‘fuzziness’ due to poor auditory processing)
distal causes of DLD> early theories> (3)
- “bad parenting”
- repeated ear infections during crit period for lang development
- brain damage sustained around birth
distal causes of DLD> twin studies>
- monozygotic twins found to resemble each other in terms of DLD diagnosis more closely than dizygotic twins
- suggests there is a genetic component that causes DLD
distal causes of DLD> a ‘language gene’?
- mutation on FOXP2 gene linked with abnormalities in ‘broca’s area’
- abnormality identified in studies of ‘KE’ family, many of whom have lang difficulties
distal causes of DLD> A ‘language gene’> nativist view>
- nativist view of lang development that there is an innate lang ‘faculty’ which encodes grammar & which is genetically specified
- idea genes of children with DLD impair their grammar while sparing their intellgence
distal causes of DLD> evidence against ‘a language gene’
- idea studies of KE family helped identify one route by which genetic variation affects brain development & subsequent lang capacity
- most people with DLD do not have abnormality of FOXP2 gene & seems likely in most cases the disorder is caused by the interaction of several genes together with environmental risk factors
distal causes of DLD> atypical brain development & cortical dysplasia>
- suggestion atypical neuronal migration causing ‘cortical dysplasia’ as linked to DLD
- cortical dysplasia as occuring when top layer of brain doesnt form properly (either genetic/due to brain injury)
distal causes of DLD> atypical synaptic pruning
- during synaptic pruning, the brain eliminates extra synapses
- synaptic pruning as though to be brains way of removing connections in brain that are no longer needed
- suggested ‘synaptic pruning’ process as different in kids with DLD
future research agenda of DLD> (6)
- better understanding of genetic basis of DLD
- better understanding of the underlying NEURAL mechanisms involved
- determine optimal methods of identification
- improve intervention efficacy
- study more diverse population
- better understanding of link with comorbidities such as dyslexia
