Learning disability often refers to an intellectual disability. A specific learning disability or specific learning disorder often refers to dyslexia. Diagnosis was based on the discrepancy between an individual’s intellectual functioning and one’s academic functioning. However, it was not sure how this should be applied (1), critique that it favours older children and people with higher IQ (2) and concerns that this model is failure based (3).

Another method of diagnosing is response to intervention (RTI) which refers to a tiered system of interventions that can be applied and failure to respond is a criteria for SLD. However, this does not take IQ into account. According to the DSM-5, a specific learning disorder occurs when there are academic skills that are substantially and quantifiable below those expected for somebody’s chronological age. When a sensory deficit is present, the learning disorder must be in excess of what would be expected given that deficit.

Prevalence rates of SLD are 2% to 10% although this varies widely due to definitional issues. Children with learning disabilities have more social difficulties. Social skills deficits can represent an SLD though social deficits can occur without an academic deficit. Social skills deficits may also emerge prior to SLD and persist into adulthood. Children with a SLD are more often neglected or rejected by peers.

Social competence can be undermined in three ways:

• Skill deficit
  This holds that the individual has not learned the required skill.
• Performance deficit
  This holds that the individual has the skill but does not apply it.
• Self-control deficit
  This holds that the individual demonstrates aversive behaviours that compete or interfere with the acquisition and performance of appropriate social skills.

Social competence refers to a trait that determines the probability of completing a social task in an acceptable way. Social skills refer to the behaviours that are exhibited in social situations that produce socially acceptable outcomes. People with SLD typically have low self-esteem and a poor self-concept.

There are five specific learning disabilities:

1. Dyslexia
   This refers to a deficit in reading and deficits include decoding (1), comprehension (2), fluency (3) and left-hemisphere dysfunction (4).
2. Dysgraphia
   This refers to a deficit in written expression and deficits include organization (1), spelling (2), grammatical structure (3) and punctuation (4).
3. Dyscalculia
   This refers to a deficit in mathematics and deficits include number sense (1), estimation (2) and problem solving (3).
4. Non-verbal learning disability
   This refers to a deficit in visuospatial areas and deficits include right-hemisphere dysfunction (1), weak math skills (2), proprioception (3), balance (4) and social pragmatics (5).
5. Dyspraxia
   This refers to a developmental coordination disorder (DCD) and deficits include balance (1), fine and gross motor skills (2) and manual dexterity (3).

Dyslexia is the most prevalent specific learning disability. In dyslexia, the reading problems are not caused by general cognitive limitations or other environmental factors (e.g. socio-economic status). The disability impacts the acquisition of basic reading skills. Developmental dyslexia refers to a neurobiological disorder where one has difficulties with accurate and/or fluent word recognition and poor spelling and decoding abilities as a result of deficits in phonological awareness.

The prevalence of dyslexia is 5% to 17% and it may go unnoticed until formal schooling begins. Children with dyslexia also often have executive function problems seen in ADHD. There is a high comorbidity between ADHD and dyslexia. More men than women are diagnosed with dyslexia with an 8 to 1 ratio.

The genetic effects of dyslexia are most pronounced in children with high IQ. Systems responsible for processing expressive and receptive language (1), verbal working memory (2), executive functions (3) and processing speed (4) are associated with dyslexia. The left hemisphere posterior brain system does not respond appropriately when reading in people with dyslexia. A laborious system of phonetic awareness and a more rapid decoding system are used to develop reading ability. There is underactivity in both areas for people with dyslexia (i.e. deficit in phonemic awareness and RAN).

Cognitive assessments are important for identification and intervention for dyslexia. The following needs to be addressed:

• The range of intellectual functioning.
• Any deficits in reading achievement and the specific nature of the deficits.
• Strengths and weaknesses in cognitive processing.
• Processing deficits not caused by environmental conditions.

Phonemic instruction and early intervention are essential in the treatment of dyslexia. Later interventions are less successful. Graphic organizers may help people with dyslexia in organizing information, aiding in comprehension, and assist in recall.

People with dysgraphia have difficulties planning (1), organizing (2), revising (3), transcribing (4) and translating ideas into written content (5). There may be problems in handwriting (1), spelling (2) and global deficits (3). While children typically have difficulties writing, the problems persist beyond an age where they should self-correct (i.e. 8 years of age). The prevalence rates are 1.3% to 2.7% in early primary school and 6% to 22% in middle school. Dysgraphia and dyslexia are often comorbid with each other.

Dysgraphia involves the actual transcription process (1), the mechanical or technical aspects of the process (e.g. grammar; punctuation) and the organization of information to be transcribed (3).

The underlying neurocognitive processes of dysgraphia are not known. It appears as if memory attention (1), graphomotor output (2), sequential processing (3) and higher-order verbal and visuospatial functions (4) play a role.

Children with dyscalculia have deficits in their ability to process information related to numbers and mathematical procedures. A mathematics learning disability (MLD) refers to limitations in mathematical understanding that can be described as a deficit in understanding number sense. This impedes an ability to perform activities that involve problem solving or retrieving mathematical information.

The prevalence is 5% to 10%. There is a big genetic factor of dyscalculia and there may be a general neurocognitive deficit (e.g. executive functioning). There may also be a specific deficit (e.g. approximate number sense). The approximate number sense refers to a system that is accessed to make quick decisions regarding mathematics.

Early screening is important for dyscalculia since the mathematics curriculum is cumulative. Interventions need to be frequent and intense.

People with non-verbal learning disabilities (i.e. visuospatial learning disability) have weaknesses in the performance (i.e. visuospatial) areas but strengths in the verbal areas (e.g. vocabulary; comprehension). It is attributed to right-hemisphere dysfunction with associative problems in visuospatial processing. There are deficits in some dimensions of tactile perception (1), visual perception (2), complex psychomotor skills (3) and dealing with novel circumstances (4). The children are often clumsy and have poor coordination due to a poor sense of proprioception. They have slow processing speed but excel at reading. They have a weakness for facial recognition and other visuospatial tasks.

The prevalence is 0.1% but the prevalence rate may be underestimated due to overlap with Asperger’s syndrome and because many people are unfamiliar with the disorder. The degree of deficit is related to the amount of damage to the right cerebral hemisphere and white matter contained in this area. The white matter model states that acquired or congenital brain damage reduces the amount of white matter which leads to a disconnect between left and right hemispheres of the brain. Assessment should include neurological assessment and social skills and related abilities.

People with dyspraxia (i.e. developmental coordination disorder; DCD) demonstrate immaturities in fine and gross motor skills. They experience problems in posture (1), movement (2) and coordination (3). The prevalence is between 5% and 6% for children aged 5 to 11. It is more common in males than in females and comorbidity with ADHD is high.

Early warning signs include difficulty buttoning clothes (1), tying shoes (2), limited athletic ability (3) and difficulty completing tasks requiring precision (4). Motor milestones are often delayed. Central nervous system dysfunction may be the cause of dyspraxia.