LD: AETIOLOGY AND DIAGNOSIS
Definitions
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There is no widely accepted definition of “Learning Disability”, (LD), and within this field, there
is ongoing debate as to what LD actually means.
In the past, labels have included terms such as “mental retardation” (International statistical
Classification of Diseases and related health problems-10 (ICD-10), WHO, 2016), “mentally
defective”, and “mental handicap”.
People within the disability movement in the UK currently tend to prefer the term “learning
disability”. However, the term ‘intellectual disability’ is increasingly used. The term ‘Learning
Disability’ will be used throughout the lecture series.
The most recent definition uses the term ‘disorders of intellectual development’. The description is
as follows
WHO definition in ICD-11 (2018):
“Disorders of intellectual development are a group of etiologically diverse conditions originating
during the developmental period characterized by significantly below average intellectual
functioning and adaptive behavior that are approximately two or more standard deviations below
the mean (approximately less than the 2.3rd percentile in cognitive ability), based on appropriately
normed, individually administered standardized tests...”
Hammill, Leigh, McNutt and Larsen, (1981) describe LD thus:
“Learning disabilities is a generic term that refers to a group of disorders manifested by significant
difficulties in the acquisition and use of listening, speaking, reading, writing, reasoning, or
mathematical abilities. These disorders are intrinsic to the individual and presumed to be due to
central nervous system dysfunction. Even though a disability may occur concomitantly with other
handicapping conditions, it is not the direct result of these conditions”.
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In the USA there is a wealth of literature and research on LD. Some American literature still
refers to disability as “mental retardation” or “mental handicap”.
Recent changes are that the Diagnostic Statistical Manual of mental disorders –V (DSM-V)
(American Psychiatric Association; 2013) uses the term ‘intellectual development disorder’.
The DSM gives a description of adaptive functioning further alongside
intellectual impairment with 3 areas highlighted:
1. Conceptual – language, literacy, memory
2. Social – empathy, social judgement
3. Practical e.g. self-care, money, organising self
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In the UK the view that there is a continuum of LD focusing on psychological and social
adaptation to the world has been in evidence for longer.
Unlike the USA, the shift is away from labelling and categorization of a LD and identifying
what the special educational needs are, as well as targeting the child or adults strengths.
Children who have an IQ of 70 upwards are included within mainstream school settings, and
frequently now children with the labels of SLD and PMLD may do too.
Traditionally, use of IQ scores has been a method of grading intellectual disability.
The DSM-V (APA, 2000) uses four descriptors to categorise levels of learning
disability:
1. Mild IQ 50-69. A mental age of approximately 9-11 years (at adulthood)
2. Moderate IQ 35-49. A mental age of 6-8 years (at adulthood)
3. Severe IQ 20-34. A mental age of 3-5 years (at adulthood)
4. Profound IQ 20/25 and below. A mental age of below 3 years (at adulthood) (Grossman,
1983).
ICD-11
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Indicates however that performance on tests related to centile score may not be
appropriate to use and that may need to be made based on clinical judgment based on
behavioural outcomes.
It also states that the distinction between SLD and PMLD is typically related to adaptive skills
and functioning, as it is not possible to distinguish them on standardised assessment (below
0.003rd centile).
Until 1971, children who has an IQ below 50 were designated “severely subnormal” and considered
“uneducable”, and were therefore the responsibility of Health care. In 1971, the Education Act
transferred responsibility for educating these children to the Educational Authorities. Education
Authorities used the terms Moderate Learning Difficulties,(MLD), Severe Learning Difficulties (SLD)
and Profound and Multiple Learning Difficulties,(PMLD),to describe the range of children with
learning needs, and educational settings were set up to meet these varying needs . The 1981
Education Act recognised the reluctance to “label” disabled children, and this allowed for the
increased trend to integrate children into mainstream settings. The 2014 Code of Practice continues
to use the terms MLD, SLD and PMLD as an area of need. However interestingly earlier drafts did not
include MLD suggesting that many children labelled as having MLD may be only performing at that
level due to poor teaching support (Robertson, 2015). The Code of Practice typically tends to use
the term Special Education Needs (SEN) stating that ‘learning disabilities is subsumed by this term’,
with MLD, SLD and PMLD being under the ‘cognition and learning’ area of need. In the UK services
tend to use the term ‘Adult Learning Disability’ with criteria typically reflecting people with severe
and profound LD, unless those with MLD have significant other health or physical needs that impact
their ability to function.
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What are the key differences between those with MLD and those
with SLD?
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When working with pre-schoolers with learning disabilities you may well be involved in
detailed assessments of a child’s communication needs.
One crucial aspect will be supporting the decision-making to place the child in an
appropriate educational environment.
This will involve working collaboratively with your professional colleagues to determine the
level of disability and whether a child has a moderate or severe/profound learning disability,
as well as the severity of their communication needs. The following is a summary of the
differences between moderate and severe learning disabilities:
SLD:
 Brain pathology typically evident
 Caused by an organic disorder e.g.
foetal alcohol syndrome
 Physical impairments common e.g.
CP
 Little success with academic tasks
 Likely to need ongoing support for
activities of daily living as an adult
 Found in all Socio-economic status
(SES) communities
• MLD :
• Brain pathology rarely found
• Caused by genetic and environmental
factors, often in combination e.g. parent
may have MLD, possibly abuse or neglect
• Physical skills often little affected
• May achieve level of academic skills e.g.
reading, writing
• Can lead functionally independent practical
working lives
• More common in low SES status
communities, e.g. Irish traveller families
1. SLD children frequently show evidence in the history or clinical examination of some form of
brain pathology. This is less common in MLD.
2. SLD is usually as a result of organic pathology. It is likely that the child may have other physical
impairments. (Bowler & Lister Brooks, 1997).
3. Children with SLD generally have little success with more academic tasks such as reading
and writing.
4. Adults with SLD are less likely to lead independent lives, whereas MLD people can adjust to
the adult world of work in more practical tasks.
5. MLD is more common in lower socio-economic groupings, where SLD is more evenly
distributed across all social groups.
6. MLD is most commonly due to a combination of genetic and environmental factors rather
than an organic disorder, (Simonoff et al, 1996). This can be as a result of abuse, including
neglect (Perkins & Graham-Berman, 2012).
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Core aspects that are central to learning disability as a
whole:
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People with LD have difficulties with academic achi evement and progress. Discrepancies
exist between a person’s potential for learning and what he/she actually learns.
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People with LD show an uneven pattern of development, (language development, physical
development, academic development, and/or perceptual development). They may have
language processing deficits due to limited attention skills, speed of processing, limited
phonological working memory, limited visuo-spatial working memory and difficulties with
executive function.
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Attention skills Deficits in attention appear to be inherent to LD. There are attention deficits
that may be linked to particular syndromes and are more likely when there is an organic
dysfunction. As a result, people with LD may have difficulties with selecting information,
filtering distractions, sustaining attention, habituation, transfer and general language
processing skills. Children with learning difficulties and additional physical difficulties have
been identified as having reduced joint attention behaviours, (Cress et al; 2004).The
development of joint attention and attention skills generally during social interaction are
important for social competence, language learning and the development of receptive
skills, (Baron-Cohen 1987; Morales et al, 2000; Striano et al, 2006). Attention skills are often
divided into stages (Reynell, 1978):
Stage 1: Fleeting attention briefly held by most interesting stimulus either visually or auditorily.
Stage 2: (1-2 years), single-channelled attention.
Stage 3: (2 -3years), a child can listen to language in the environment whilst performing a
task that is related to what they are being told.
Stage 4: (3-4 years), can voluntarily focus.
Stage 5: (5 – 6 years), can listen to language whilst doing another task.
Stage 6: Integrated attention and listening skills.
Memory skills: Verbal memory is also an area of difficulty in many individuals with LD, (Merrill
et al, 2003). This is a skill necessary for rehearsal of information, and is well developed by the
time a child reaches 7 years of age. People with LD do not easily show spontaneous rehearsal
skills.
Metacognitive skills: These include recall, self-monitoring, reality testing, generalisation, coordinating and controlling learning, inventiveness, and flexibility of thinking. People with LD
tend to have difficulties with information adaption and may also find generalisation of newly
learnt language skills challenging, (Merrill et al, 2003). Generalisation is also a common
difficulty and needs to be carefully considered when planning therapy goals.
Adaptive behaviour skills: Adaptive behaviour skill areas are a collection of conceptual,
social and practical skills that people have learned so they can function in their everyday
life and therefore affect their interaction with everyday settings, e.g. conceptual skills,
(language skills, literacy, money concepts, self-direction), social skills (see next), and
practical skill e.g. use of money, transport, activities of daily living, self-care. People with a LD
are highly likely to need support in these areas.
Social/emotional development skills: Children with delays are less socially interactive than
would be predicted, (Field, 1984; Guralnick, 1984). Peer interactions need to be mediated in
order to become less sustained and facilitative, (Sinson & Wetherick, 1981). Reliance on
external cues rather than on internal cognitive abilities in problem solving during the
interactive process is a significant issue. Peer learning opportunities can help promote more
confident social interaction, and therefore help develop initiation skills, (Harding, 2008).
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People with learning disabilities often have other sensory and health issues that may significantly
impact on their potential to develop:
1. Hearing: Estimates range from 5-60%, (difficulties in testing is also an issue which needs to be
considered). Estimates for Down syndrome are quoted as being 95%. Kerr et al, (2003), found
only 11% of a hospital population, (n=589), had normal hearing, (carer estimates of whether
hearing was “normal” or not were 74%).
2. Vision: Kerr et al, (2003), found vision completely normal in <1% of population studied.
3. Physical disabilities: 20-30% of people with LD may have cerebral palsy or other motor
impairments, (McLaren & Bryson, 1987).
4. Epilepsy: Kerr et al, (2003), found that 34% of the people studied had an active problem with
fits, 17% were in remission, and anticonvulsant medication was prescribed for 28%.
5. Challenging behaviour: 5-15% of people with LD display behaviours, which challenge services.
6. Mental Health: Excluding challenging behaviours, prevalence rates 25-40 %,
(25% for general population).Difficult to assess; rates could be higher. Emerson, (2003), did a
study on 10,438 children who were normally functioning as well as their LD peers. 39% had a
psychiatric disorder in the LD group, (8% in non-LD group), 25% had conduct disorders, and 9.5%
had emotional disorders.
7. Nutritional difficulties: Kerr et al, (2003), found that 57% of the group interviewed had some
level of difficulty related to eating and drinking. 22% were overweight; 14% were underweight;
21% had a combination of syndrome-specific difficulties, e.g. i) oral-motor problems in Down
syndrome; ii) compulsive eating in Prader-Willi Syndrome.
8. Communication difficulties: 50-90% of people with LD are likely to have some form of language
and/or communication difficulty. (van Der Gaag, 1998). About 80% of people with SLD fail to
develop effective speech and/or language skills; 20% have no verbal skills, but demonstrate
some level of communicative intent; around 20% have no intentional communication skills,
(McLean et al., 1996).
9. Autistic Spectrum Disorder/Conditions: ½ -1/3 of children with ASD will have learning disability,
with boys more affected than girls.
10. Complex learning difficulties and disabilities (CLLD)/Complex health and learning
disabilities/life limiting conditions/technology dependent: The numbers of children with complex
health needs e.g. ventilation dependant, tracheostomy, tube fed, alongside learning needs is
known to be increasing (Blackburn, Spencer & Read, 2010). It may be just suitable to discuss this
as an increase in the complexity of children presenting with PMLD, rather than a new group per
se. There is no agreed term or definition for this group, and occasionally there will some children
with complex learning difficulties and disabilities who do not have learning disabilities e.g. some
children with dyskinetic Cerebral palsy.
Epidemiology/Prevalence
Within the UK, The Department of Health estimates that; “There are approximately 210,000 people
with severe learning disabilities, (children, adults, and older people)…” and “There are around 1.2
million people with mild/moderate learning disabilities”, (DoH, 2007; DoH, 2009).The National
Statistics Office suggests that about 2% of the UK population have some level of learning disability.
It is recognised that there is no official statistic, which accurately reflects this population.
MLD is more difficult to define; if it is on IQ alone, then 3% of the population have an IQ of two
standard deviations below the mean. This neglects other influences such as social competence,
educational management and family support. These variables determine if a person needs support
or not in adult life.
Emerson et al, (2012) repeated a survey to try and establish how many people in England had a
learning disability. They estimated that there were 1,191,00, an increase from 985,000 people in
2006 , including 286,000 aged under 18 years old, 905,00 adults aged 18 plus with 21% known to
Learning Disability services. 70,000 children had a statement of Special educational Needs in 2011
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with just over half categorised as MLD, 1/3 as SLD and just over 1 in 10 having PMLD. Patterns were
evident with a greater number of males to females and by some ethnic groupings e.g. MLD more
frequent in traveller families and PMLD in Bangladeshi and Pakistani communities.
Emerson et al (2004) predicted that the number of people with LD will increase by 8% by 2011, and
by 14% by 2021. The increase by 2011 was 17%.
Societal changes affecting prevalence
There are some factors where there are trends that could impact on an increased or decreased
likelihood of having a child with a learning disability.
Factors associated with increase.
Factors associated with decrease.
 Rise in maternal age.
 Availability or prenatal screening.
 Survival of at-risk infants.
 Improved health care and support.
 Increased levels of HIV/AIDS.
 Increased life expectancy for people
with LD.
 Higher birth rate in some ethnic groups
with higher prevalence rates of LD.
Causes of Learning Disability
The causes of LD are varied and wide-ranging. Many people with a learning disability may have a
specific syndrome. The causes of disability, though, fall into the following categories:
Causal factors.
Biological.
Genetic
abnormalities.
Features.
- Before birth-genetic abnormalities, endocrine disorders, infection (e.g.
Zika virus), physical damage, (e.g. radiation), exposure to toxins e.g.
Foetal Alcohol syndrome.
- During birth-e.g. anoxia.
- After birth-infection, (childhood encephalitis, meningitis, measles),
injury, endocrine, (e.g. congenital hydrothyroidism).
- Autosomal, (non-sex linked) e.g. Down syndome.
- Sex-linked chromosomal abnormalities, e.g. Fragile X.
- Other, e.g. Rett’s Syndrome.
Behavioural
phenotypes.
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Behavioural endowment, (genotype), expressed through physical
structure/behavioural patterns. Or genetic predisposition.
Environmental
factors
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Exposure to toxins e.g. lead
Malnutrition
Abuse, including neglect
Information on syndromes
The word “syndrome” means “to run together”, and “dysmorphic” means “abnormally
formed”. Therefore, the term refers to a collection of abnormalities of bodily structure that are found
to cluster together more often than would be expected by chance. The cause may be a
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chromosomal disorder, a defective single gene, exposure to an adverse intrauterine event, e.g.
infection, toxin, or a biochemical disorder, (toxoplasmosis, intrauterine insults, alcohol, etc). Around
200 syndromes have already been identified. With dysmorphic syndromes, there are ranges of
terminologies:
Term.
Malformation.
Deformation.
Meaning.
A primary structural defect.
Alteration in shape or structure of a previously normal part.
Anomalad.
A malformation together with its consequential structural
change.
Recognized patterns of malformation presumed to have a
common aetiology.
Malformation syndromes.
Association.
A pattern of malformations occurring together more often
than expected by chance but not definitely regarded as a
syndrome.
There may be a collection of expected language and communication challenges for the
clinician associated with a specific syndrome. Whereas it is important to bear key features in mind
when working with a client, it is still important to intervene using a client centred approach, focusing
on communication strengths and individuality.
As a clinician, the key issues when dealing with a wide range of syndromes are:
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Consider the parents feelings, their emotional state as well as their child’s strengths and
needs.
Focusing on medical aspects may detract from concentrating on the real care and needs
issues.
No group with a given name is totally heterogeneous. There is a wide diversity, and therefore,
although it is important to consider up to date literature and research, the person you are
working with also has individual needs.
The diagnosis needs to be reviewed.
Giving a diagnosis needs to be done with consideration of the parents’ emotional state, and
support need to be identified and arranged at this time.
Some behaviour patterns may be associated with specific syndromes.
Parents may be advised by the Consultant Paediatrician involved in their child’s care that
they need genetic counselling.
Support groups can be highly supportive and beneficial for parents and their families.
Living without a diagnosis/cause established can have its own particular stresses as can
having an incredibly rare one, where little is known.
Be aware that children with a disability are 3 times more likely to have a parent with a
disability (Blackburn, Spencer & Read, 2010) and that children from lower SES are more
commonly represented in the MLD group.
The Handsel Trust is an organisation that looks at supporting parents and families and considering
the most effective ways of working with families: http://www.handseltrust.org
Contact a Family is another useful organisation that provides information and support for families
and practitioners:
http://www.contactafamily.org
Unique is an organisation to support families with incredibly rare chromosomal disorders
http://www.rarechromo.org/html/home.asp
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The 100,000 Genomes Project is aiming to provide diagnosis and explanations to many children and
families for their learning disability http://www.genomicsengland.co.uk/the-100000-genomesproject/
SWAN (Syndrome Without A Name) UK is an organisation that aims to support families when their
child does not have a unifying diagnosishttps://www.undiagnosed.org.uk/
More specific information on syndromes
Chromosome disorders: Chromosome disorders are the commonest and most familiar of all
dysmorphic syndromes. The incidence is quoted as being one in 660 of all live births. There are some
chromosomal disorders where the genetic origin is still unclear, e.g. Rett’s syndrome, where it is felt
that it is caused by a mutation of a dominant gene on the X chromosome. This is common in girls,
but a very few cases have been described in boys, but whether these actually represent the same
condition is unclear.
Autosomal abnormalities are the most common chromosomal abnormalities. The majority of human
chromosomal abnormalities occur in the AUTOSOMES, (any other chromosome other than a sex
chromosome). Human somatic cells have 22 pairs of autosomes and one pair of sex chromosomes.
The most common autosomal abnormality is Down syndrome where there are three chromosomes
on 21, (trisomy 21). Other examples are Cri-du-chat syndrome and mosaicism (where the cells have
different numbers of chromosomes in e.g. 80% have 3 21 chromosomes and 20% have 2 21
chromosomes).
Sex chromosome disorders involve the sex chromosomes. Abnormalities in this area are less
common than autosomal abnormalities, and are usually less severe in their effects.
Female sex-linked chromosome abnormalities include Turner’s syndrome, and metafemales,
(XXX).
Male sex-linked chromosome abnormalities include Fragile X, (1 in every 1,360 males), Triple
X (XXX) syndrome and Klienfelter’s syndrome, (XXY).
Single-gene defects refer to inherited metabolic and storage disorders. This includes disorders of
amino acid, carbohydrate and uric acid metabolism, and a variety of storage disorders due to
lysosomal enzyme defects and peroxisomal and mitochondrial disorders. Infants usually present with
hypotonia, convulsions, vomiting, megalblastic anaemia or gross developmental delay.
Behavioural phenotypes refer to aspects of an individual’s development and behaviour that can
be attributed to the presence of a specific genetic or other biological anomaly. It covers
vulnerability to psychiatric and psychological disturbance as well as cognitive, (intellectual)
difficulties. It is therefore not an environmental or handling issue. Examples include Lesch-Nyhan
syndrome, Rett’s syndrome, Cornelia de Lange syndrome, Prader Willi syndrome, and Aicardi
syndrome.
Abnormal head size: A large head (macrocephaly) is one which when measured is above the 98th
centile. Development and progress with these individuals is usually normal. However, large head
size can be an observed indication of hydrocephalus whcih is an imbalance between production
and re-absorption of cerebrospinal fluid, which leads to ventricular enlargement. The ventricles may
also be bigger due to atrophy or loss of brain substance. There may be resulting LD and possibly
gross-motor difficulties.
Small head size (microcephaly) is usually the result of severe intra-uterine growth retardation/insults
to previously normal foetuses. Damage could be as a result of radiation, foetal alcohol syndrome
or intrauterine infections. Post birth causes include severe anoxia, asphyxia, accidental or nonaccidental injury, Angelman’s syndrome, vascular accidents and inherited metabolic diseases.
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Congenital infections:
Three main infections, which are of particular interest in terms of
disability, are cytomegalovirus, rubella, and toxoplasmosis. The infections normally cause only
trivial/sub-clinical illness in the adult, but when a primary first infection occurs in a susceptible
woman during pregnancy then they may cause severe foetal damage. Other infections include
chicken pox, syphilis, herpes simplex, and recently in the news, Zika virus.
Other prenatal causes include substance abuse, (morphine, heroin), perinatal insults, (asphyxia,
meningitis, metabolic disorders), postnatal disorders, (CNS infection, non-accidental injury,
convulsions, environment, maternal illness)
Speech and language therapy approaches to working with people
with a learning disability
There are a variety of approaches to consider as a therapist when working with people who
have disabilities. There is no one particular approach that will suit your entire client group. Each case
will need careful assessment on a needs led basis. Within the field of disability, particularly adult
work, a Person Centred approach (DoH, 2001) is recognised as being an appropriate starting point
for intervention and management of cases. This is where a client has individualized goals developed
both with them and the multi-disciplinary/agency team, and where the person’s strengths are used
as an important starting point for goal setting. This approach is becoming more evident in childrens
services with the use of Team around the Child/Family approaches (Limbrick, 2001).
Evidence suggests that approaches focusing on semantics and pragmatics are most likely
to benefit from intervention, and are most likely to continue to develop throughout the lifespan of
individuals. Phonology and morphosyntax are considered more difficult areas to achieve gains in
therapy. However, this does not mean to say that intervention in these areas should not occur. There
is much discussion around this area, with consideration of critical periods of development, alongside
the client’s ability to attend more on the specific tasks, as well as developing an understanding of
the task requirements, developing self-monitoring skills, and an awareness of the area being
targeted, with the ability to integrate what is being learnt into connected speech and everyday
communication contexts.
Therapy may take place within a one to one setting, group or in a naturalistic setting.
Selection of a setting should link closely to a person’s communication goals. Each approach has
benefits, although the function of each approach is different. The following are definitions of models
of service delivery as taken from Abudarham & Hurd, 2002, p94:
Direct (Individual Therapy): Working directly within individual, concentrating on developing their
communication abilities
Direct (Group Therapy): Working directly within specifically planned groups, to develop targeted
skills of two or more individuals
Indirect (Individual Therapy): Working indirectly with an individual by working through significant
others to develop their communication environment or targeted skills. May include training.
Indirect (Group Therapy): Working indirectly, through the significant others to develop targeted skills
of two or more individuals within specifically planned groups.
General Teaching: Teaching that is not specifically planned to meet an individual’s need, but to
develop overall awareness, communication skills, etc.
Therapy also needs to be put into a context:
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Individual
communication needs.
Specific communication
components.
Family, home, work,
school, other
environmental contexts
including e.g. transition.
Developmental and lifespan perspective.
However you decide to implement your therapy, you need to consider what sort of approach you
are going to take with your client. Within the field of learning disability, it is highly likely that therapy
is going to be focusing on Participation Factors and Environmental / Personal Factors within the ICF
Framework (WHO).
The following are the main types of approaches used with people who have learning disabilities.
A Developmental approach:
 This is where the normal sequence of development is used as the basis for assessment and
selection of targets for therapy.
 This may lead to ceiling on expectations and opportunities if people do not progress at a fast
enough pace.
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 Some Developmental Approaches may be termed “Growth Models”. Development may be
considered within different contexts such as maturational or constructivist models.
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A Functional approach:
This approach is used commonly with people who have learning disabilities, particularly adults.
The perception is that adults will not learn new skills, so the focus should be on consolidating
what they already can do, and maximising these skills within everyday and familiar contexts.
Targets should be selected that will have the greatest impact on communication: therefore, it is
important to analyse daily routines and identify skills needed for interactions.
This approach may lead to a trial and error approach to goal setting. It lacks a clear theoretical
framework to guide progress, although having opportunities to develop the confidence to
interact competently with peers is acknowledged as a positive outcome of such an approach.
A Psycholinguistic approach:
This approach focuses on language processing theory, explores linguistics through phonology,
morphology, syntax, semantics and pragmatics, and builds on a person’s strengths. The in-put and
out-put language processing model is an important part of this approach. It has four major
underlying principles:
1. It is necessary for a level of cognitive intentionality to be present so that there is an established
learning matrix to enable the person to develop further.
2. Early communication attempts such as non-recognizable words are viewed as being
expressions of semantic relationships, i.e. they have the meaning and content of words, and
by treating them as such, it is anticipated that this will be a motivator for the person
developing the language.
3. Semantic relations are an important aspect: meanings develop through events and object
relations experienced by the client. Context is therefore essential to the communication
learning.
4. Language development is built in part on cognitive development, i.e. the person’s actions
on and knowledge about an object and the environment as well as the relationships
between them, (Stackhouse & Wells 1997).
A Sociolinguistic approach:
This approach strongly emphasizes the social setting. It has five fundamental principles:
1. Language is acquired only if the person has a reason to communicate.
2. The person develops utterances of increasing complexity through the opportunity to listen,
process and decode new linguistic structures, i.e. modelling opportunities.
3. Language is learned in dynamic social interactions involving the person and more
competent communicators.
4. Language is first acquired as a means of obtaining things that the person could previously
get, or do, by simpler communication methods.
5. Clients are active participants in the language/ learning situation, and they bring to this
process a set of behaviours both social and cognitive which allows them to benefit from the
therapists’ facilitating behaviours.
A Didactic Approach:
Didactic approaches are usually associated with Behaviouralist methods of intervention. Such
approaches rely on Critical Phases of development, i.e. acquisition of a skill, generalization of a skill,
and, maintenance of skills learnt.
Operant methods are used within such approaches: this is where behaviours are learned and
acquired through reinforcement; behaviours that are not reinforced will be extinguished.
Social learning: behaviours are learned through observation of positive social interactions as follows:
 Massed trials on specific targets
 High rate of reward
 One-to-one teaching in a distraction-free environment.
 Agent of change is the therapist/trainer
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Didactic approaches can lead to gains in targeted performance (e.g. teaching of requests),
but often fail to generalise to everyday interactions, to other linguistic targets, and do not seem to
promote the acquisition of linguistic knowledge (e.g. rules). Such approaches are also often
criticized as they do not often occur within an everyday environment, require intensive in-put and
also have an impact on a normal family routine due to the heavy time demands of such a
programme.
Reinforcement seems to play a limited role in the acquisition of language – at least as
conceptualised within operant learning, (Warren & Kaiser, 1986).
In summary, you can teach communication behaviours, but what is harder to teach is the
motivation to communicate and use the learnt communication behaviour interactively (Nind &
Hewett, 1993).
A Milieu approach: (Hart & Risley, 1992: 1995; Warren 1991; Yoder, Warren & Hull, 1995; Yoder &
Warren, 2001).
 This approach is usually recommended for pre-verbal communicators, and uses similar principles
to approaches such as Intensive Interaction, (Nind & Hewitt, 1993). The Milieu Approach is based
on Transactional Theory, where someone has the potential to develop through interaction with
his or her environment, (MacLean & Snyder-MacLean, 1978.)
 Agents of change are the usual interactive partners: parents, siblings, teachers, learning support
assistants and care staff.
 Features of child directed language (CDL) are built into the programme when it is carried out
with children, since these are assumed to facilitate language development: e.g. response to
spontaneous attempts to communicate.
 The environment is changed to increase the probability that a particular communicative
function will be used. Going about changing the environment relies on training significant others
involved with the client.
 Responses to the person’s focus of interest are encouraged.
 Targets are selected slightly in advance of the person’s current level of competence to enable
them to develop and confidence-build their skills.
 Joint attention is a main focus of the approach to support and develop acquisition
opportunities.
 A hierarchy of prompts may be developed to encourage the person to achieve goals.
 Responses with reinforcers that are naturally linked to the target are encouraged – i.e.
appropriate to the social interaction.
 Although this approach has many positive benefits, it is an approach where there is a
dependence on spontaneous initiations by the individual. The failure to initiate as well as
passivity is characteristic of many individuals with learning disability. In addition, individuals with
learning disability may not communicate frequently enough to benefit from the provision of
incidental opportunities.
Recent versions of Milieu Approaches incorporate elements of didactic strategies in order to
encourage initiation and frequency of use:
Example: use a prompt such as “Tell me what you want”, followed by the elicitation of imitation
“Say juice”; expectant time delay: pause for 5 sec (or until person initiates communication), then
prompt with visual support, hand over hand support, and so on.
Summary:
 Different methods may be appropriate for different individuals.
 Some aspects of language are more naturally suited to one method than another.
 A functional approach helps to ensure that targets are relevant to the needs and interests of
individuals.
 Developmental approaches provide a framework for determining starting points and assessing
progress.
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Didactic methods may be useful in teaching the knowledge of a structure or meaning.
Milieu approaches seem to be the best way of encouraging everyday use.
Many therapists use a mixture of approaches or a blended form of model as described by Paul
(2001) in the Descriptive Developmental Model.
Although the approach chosen is vital. Training of significant others and management of the
communication environment is going to be a major focus of intervention by therapists working
with people who have learning disabilities. (Money, 1997; Brown, 1998).
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