Definitions

Types of learning disabilities

There are a number of ways of categorising learning disabilities (LD). The Diagnostic and Statistical Manual (DSM-IV-TR) of the American Psychiatric Association is one of the most commonly used categorisations. It lists three types of LD:
• Disorder of reading
• Disorder of written expression
• Mathematics disorder.

Other types of LD commonly referred to in assessment reports and in the research literature are:
• Dyslexia
• Nonverbal learning disabilities
• Language learning disabilities.

It is very common for a student to have more than one type of LD.

LDs are assumed to result from deficit's in information processing. In assessment reports it may be noted that a student has problems with, for example, phonological processing, auditory processing, visual processing or short-term memory.

Developmental learning disability refers to a learning disorder which is presumed to have been present from birth.

Acquired learning disability refers to a learning disorder which is only present after a brain injury, such as a stroke, traumatic head injury or brain tumour.

Common symptoms associated with LDs

As well as the specific symptoms listed for each type of LD, there are other features and disorders which are quite commonly associated with LDs. These include:
• delays in language development
• visual perception deficits
• memory problems
• attentional problems
• poor motivation
• disorganisation
• poor social skills
• behavioural disorders, such as conduct disorder or oppositional defiant disorder
• low self-esteem
• depression.

Language learning disability
An LD that is characterised by language processing difficulties is termed a language learning disability (LLD). These disorders are diagnosed by speech pathologists, usually in childhood. Other equivalent terms are:
• Language disorder
• Communication disorder
• Specific language impairment.

Subtle language learning disabilities, including difficulties with higher level language tasks such as comprehension or conceptual understanding, may be not be detected until late primary school, high school or adulthood. If a psychologist detects symptoms of a possible Language learning disability during a psychometric assessment the student should be referred to a Speech Pathologist for a language assessment.

A Language learning disability refers to a specific and significant deficit in either:
• expressive language, that is, the processes we use when expressing ourselves in speech, writing and/or sign
   languages (such as Auslan) and/or,
• receptive language, that is, the processes we use in understanding others through listening, reading and/or
   sign language (such as Auslan).

Not all individuals with Language learning disabilities have literacy problems. However, because of the demands for high standards of written and oral language at university, it would be uncommon for university students with Language learning disabilities not to have difficulty meeting these standards. A speech pathologist can determine the extent to which language deficit's contribute to a student's academic and social problems.

Problems which are characteristic of adolescent and adult students with Language learning disabilities include:

• Expressive language and conversation
– word retrieval problems
– fragmented sentences
– frequent use of low-information words (e.g, thing, stuff )
– inability to give clear directions
– difficulty explaining new concepts
– false starts and circumlocution (talking round a point or issue)
– abrasive conversational speech
– language use confuses listeners
– make 'black and white' and impulsive judgments
– consistently violate conversational rules.

• Listening
– poor listening skills
– difficulty following directions
– difficulty grasping the essential message of a lecture
– difficulty comprehending slang/jargon resulting in social difficulties.

• Thinking and reasoning
– limited strategies for finding, selecting and utilising information
– difficulty placing concepts in a hierarchy.

• Literacy
– poor processing of information obtained through reading
– difficulty following written instructions
– poor at conveying meaning through written language.

• Nonverbal communication
– violate rules for social distance
– misinterpret body movements and facial expressions.

The Psychologist conducting the psychometric assessment should refer the student to a Speech Pathologist for a language assessment if the following was noticed:

• marked language difficulties, such as those listed above
• a marked difference between the measures of the student's verbal and nonverbal abilities, with the nonverbal abilities being markedly higher.

Refer to Identification and Testing of learning disabilities for further information.

References

Larson, VL & McKinley, N 1995, Language disorders in older students: preadolescents and adolescents, Thinking Publications, Eau Claire, Wisconsin

Patchell, F & Hand, L 1993, 'An invisible disability - language disorders in high school students and the implications for classroom teachers', Independent Education, December, pp. 31-36

Reed, V 1986, 'Language disordered adolescents' in V Reed, (ed) An introduction to children with language disorders, Macmillan, New York

Weller, C, Crelly, C, Watteyne, L & Herbert, M 1992, Assistive language disorders of young adults with learning disabilities, Singular Publishing Group, San Diego, California

What is Dyslexia?

Janet Fletcher, Steve Heath and John Hogben - Child Study Centre, Department of Psychology, University of Western Australia

Many reading researchers now agree that Dyslexia involves a surprising failure to learn to read. This problem occurs when children with adequate intelligence fall substantially short of the expected level in reading, in spite of normal educational and socio-economic opportunity.

This type of reading difficulty is sometimes called Specific Reading Disability to distinguish it from the reading problems which occur for children with low general ability.

What is thought to cause Dyslexia?

We know that humans are not “hard wired” for reading because it is a relatively recent development in human history that all individuals should be expected to read efficiently.

It is thought that visual, auditory, linguistic and neurological processes are involved in the act of reading, or recognising groups of letters as words. Still more complex processing is likely to be involved in understanding what is read.

Researchers believe dyslexic children have problems in one or more of the processes underpinning word recognition. The evidence strongly suggests that a predisposition to these difficulties is inherited.

Many of the above processes have been investigated as possible causes of dyslexia, and it is now clear that more than one factor is likely to be involved. So, dyslexic children will have different individual profiles even though they will have some common difficulties.

There now appears to be a strong consensus among researchers that around two thirds of dyslexics show core deficits within the component of the language system that is responsible for processing the sounds of speech, also called phonological processing.

These deficits in phonological processing show up as poor phonological awareness when a child seems not to be aware of the sound structure of language: e.g.,

•  slow to learn rhymes
•  doesn't seem to “hear” sounds properly
•  can't segment words into syllables and individual sound units or phonemes
•  can't manipulate phonemes
•  can't recognise words with common phonemes

Children with this core phonological processing problem may also have a very poor short-term memory for verbal material. So they are very poor at remembering instructions, or lists of words, spellings etc. They may also have difficulty with retrieval of verbal material from long-term memory and seem not to automatise phonological processing the way other children do.

Other difficulties associated with Dyslexia

These problems mean that often children with substantial reading deficits also have significant difficulties in spelling as well.

It seems that some very bright children with this core deficit actually compensate for their problems so well that they do eventually learn to read, even though it takes them longer to learn than other children. But they continue to have moderate to severe problems with spelling and written expression.

A very close relationship has also been found between dyslexia and deficits or delay in oral language, and between specific language impairment and literacy problems.

Problems have been reported in other areas of linguistic processing, s well as auditory-visual integration, visual functioning, perceptual-motor skills, hand-eye coordination, automatising skills, and arithmetic.

Difficulties in word recognition also absorb attentional capacity which might otherwise be allocated to comprehension and higher level thinking, and they prevent access to the knowledge base available to other children.

These problems are likely to establish a vicious cycle of failure , in which the dyslexic child simply gets poorer in achievement, motivation, confidence, self-esteem, social relationships and attitudes to school.

Outcomes for these children have been shown to be very much better where they receive support and encouragement at home, and specialised attention at school.

The chances of such support being available would be much increased if children “at risk” of dyslexia could be efficiently identified in pre-school.