Language-Based Impairments

Language-based learning disabilities (LBLD) are “heterogeneous” disorders associated with young children that affect their academic skills such as listening, reasoning, speaking, reading, writing, and applied problems. It is also associated with movement, coordination, and direct attention. LBLD is not usually identified until the child reaches school age.

Symptoms of LBLD can be complex or simple according to the severity of risk factors. Dyslexia is a Language-Based Learning Disabilty  that comprises difficulties associated with reading and written language such as trouble learning new vocabulary, letters and alphabets. Trouble understanding questions and following directions, understanding and remembering the details of a story's plot or a classroom lecture, and learning words to songs and rhymes, and telling left from right.

A Language-based Learning Disability entails performance that is significantly lower on language-related tests than nonverbal tests. More specific language-based disabilities included specific neuro-cognitive deficits such as poor phonemic awareness, which can affect reading and spelling but not written expression.  It is important to diagnosed the underlying deficits that give rise to specific learning disabilities, so to provide specific strategies to tackle not only the learning problems but also the underlying causes.

Specific Language Impairment

Dorothy V.M. Bishop, University of Oxford

A specific language impairment (SLI) is characterized by difficulty with language that is not caused by known neurological, sensory, intellectual, or emotional deficit. It can affect the development of vocabulary, grammar, and discourse skills, with evidence that certain morphemes may be especially difficult to acquire (including past tense, copula be, third person singular).

Diagnostic Criteria

• Language is significantly below expected for age and IQ, usually interpreted as scoring in the lowest 10% on a standardized test of expressive and/or receptive language. 

• Nonverbal IQ and nonlinguistic aspects of development (self-help skills, social skills) fall within the broadly normal limits.

• Language difficulties cannot be accounted for by hearing loss, physical abnormality of the speech apparatus, or environmental deprivation.

• Language difficulties are not caused by brain damage.

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Common Presenting Features: 

• Delay in starting to talk; first word may not appear until 2 years of age or later.

• Immature or deviant production of speech sounds, especially in preschool children. 

• Use of simplified grammatical structures, such as omission of past tense endings or the auxiliary “is,” well beyond the age when this is usually mastered. 

• Restricted vocabulary, in both production and comprehension. 

• Weak verbal short-term memory, as evidenced in tasks requiring repetition of words or sentences.

• Difficulties in understanding complex language, especially when the speaker talks rapidly. 

Differential Diagnosis

SLI is not associated with other factors such as hearing impairment, autism spectrum disorder (ASD) and Global Development Delay. SLI children function within the normal range in nonverbal linguistic areas, such as nonverbal social interaction, play, and self-help skills (e.g., feeding and dressing themselves). 

Another term used to describe SLI is Developmental Language Disorders and often coexists with attention deficit/hyperactivity disorders and oppositional behavior. This co-morbidity is explained by the proximity of the areas in the brain that are responsible for language, behavior management and executive functions. 

Although SLI is not a reading disability, 50% to 70% of children with SLI also have a reading disability such as one based on phonological weaknesses and poor phonic skills. 

Prevalence and Etiology

The prevalence of SLI has been estimated at around 7%, although this will vary with both the diagnostic criteria and children’s age: Long-term language impairments that persist into adulthood are less common than milder delays in preschoolers, which may resolve with time. SLI is more common in boys than girls. 

The various underlying skills that are impaired in SLI have different causes, some genetic and some environmental. However, a gene for language disorders has yet to be found. Nonetheless, in a three-generational KE family from London, England, SLI affects 50% of the children of an affected parent, and it is caused by a mutation affecting a piece of DNA on a gene on chromosome 7. 

Interventions

Some preschool programs have been designed to enrich the language development of students with this disability.  The focus of class activities could be role-playing, sharing time, or hands-on lessons with new, interesting vocabulary. Interaction among children is strongly encouraged. 

References

Leonard, L.B. (1998). Children with specific language impairment. Cambridge, MA. MIT press. 

Rice M., & Wilcox, K. (Eds.). (1995).  Building a language focused curriculum for the preschool classroom. A foundation for life-long communication (Volume I). Baltimore: Brookes Publishing Company. 

Semantic Pragmatic Disorder

Diagnostic Features

Persons with Semantic Pragmatic Disorder have particular trouble understanding the meaning of what others are saying, and they are challenged in using language appropriately to meet their needs and interact with others. Children or adults with this disability often have delayed language development and exhibit difficulties with both semantics and pragmatics. Semantics is the aspect of language function that relates to understanding the meaning of words, phrases and sentences, and using words appropriately when speaking.  Pragmatics is the area of language function that embraces the use of language in a social context.

      Semantics

• Aphasic speech: word search pauses, jargoning, word order errors, word category errors. 

• Pronouns or pronoun reversal, verb tenses, idioms, and slang expressions.

• Abstract words, words that relate to feelings and emotions.

• Understanding questions, satire and jokes, choices, or stories.

• Reading comprehension, identifying key points in a sentence, and summarizing text.

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      Pragmatics

• Reading body language, maintaining proper eye-contact, responding to nonverbal aspects of language (reacting to the other person’s body language and “mood”).

• Understanding contextual cues and explaining or describing an event.

• Initiating conversation and answering questions when asked.

• Following conversations and participating in them by taking turns with other speakers.

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Assessment and Diagnosis

The diagnosis of isolated semantic processing difficulties, isolated pragmatic processing difficulties or combinations of the two is done on the basis of a psycho-educational assessment that includes both cognitive and language measures.

A useful assessment tool is the Test of Language Competence—Expanded Edition (TLC-Expanded), which evaluates a child’s comprehension and usage of connected language in terms of syntax, semantics, and pragmatics.

The Test of Problem Solving (TOP3) as a cognitive language test assesses children’s and teens’ ability to integrate semantic and linguistic knowledge with reasoning ability.

Differential Diagnosis

Semantic Pragmatic Disorder is defined as a Language-based Learning Disability, which impacts on communication and information-processing. However, characteristics of pragmatic and/or Semantic Disorder overlap with High Functioning Autism, Asperger’s Syndrome, Hyperlexia, PDD-NOS, Nonverbal Learning Disability, Attention Deficit Disability or even Attention Deficit and Hyperactivity Disorder, and Auditory Processing Disorder.

There is an important difference between children with Semantic Pragmatic Disorder and children who are truly autistic. Children with Semantic Pragmatic Disorder are typically verbose; although, often, they have some mild autistic features. For example, they usually have difficulty understanding social situations and expectations, and they like to stick fairly rigidly to routines, or lack imaginative play. Also, children with semantic pragmatic difficulties do better on perceptual reasoning tests/Performance IQ. Asperger children as well as autistic children do better on verbal reasoning tests.

Prevalence and Etiology

According to research there seems to be a single underlying cognitive impairment which produces both autistic features and Semantic Pragmatic Disorder.

References

Firth, C., & Venkatesh, K.  (1998).  Semantic-pragmatic Language Disorder.  London, UK: Whurr Publishers.

The main characteristics of hyperlexia are an above-normal ability to read coupled with a below normal ability to understand spoken language. Many of the social difficulties seen in hyperlexic persons are similar to those found in autism. Often, hyperlexic children will learn to speak only by rote memory and heavy repetition.

In addition, some children who are hyperlexic could exhibit the following characteristics. 

• A precocious ability to read words far above what would be expected at a child's age

• Giftedness in some areas and extremely deficient in others

• Significant difficulty in understanding verbal language

• Difficulty in socializing and interacting appropriately with people

• Underdeveloped social skills

• Possession of very strong and/or visual memories. 

• Specific or unusual fears

• Fixation with letters or numbers

• Echolalia (Repetition or echoing of a word or phrase just spoken by another person)

• Memorization of sentence structures without understanding the meaning

• An intense need to maintain routines, difficulty with transitions, and ritualistic behaviour (e.g., self-stimulatory behaviours).

Two forms of hyperlexia have been identified:

Language-Based Hyperlexia:

This is more a language disorder.  These children have problems with expressive language because they cannot understand the overall meaning of words.  At first, their reading comprehension appears good because it has been overshadowed by excellent memory skills. They tend to have lower verbal IQ, making more phonetic errors when reading compared with the second form of hyperlexia. These children with hyperlexia show a language disorder which resembles that of an autistic child, but this similarity diminishes over time, following Speech and Language Therapy. 

Visual-Spatial Hyperlexia

The second form of hyperlexia is a visual-spatial learning disorder. These children seem to have normal language, but have difficulty cognitively interpreting the language and expressions as they see or hear them. Therefore, they exhibit deficits in visual motor integration skills, visual spatial orientation skills, and spatial memory skills. 

Prevalence and Etiology

Hyperlexia is as common in males as in females. The first form of hyperlexia that is language-based is associated with deficits in the left hemisphere. The second form that is visual spatial- based, involves a deficiency in the right hemisphere. Without coherence of language, academic problems are more prominent and social problems relate to difficulties with perception.

Differential Diagnosis

Hyperlexia can be identified in children with Autism, Asperger, Semantic/Pragmatic Disorder, Mixed Receptive/expressive Language Disorder, and Specific Language Impairment. It is commonly found in children who are considered high-functioning.

Hyperlexia needs to be differentiated from a Nonverbal Learning Disability.

References

Muller, Susan, M. (1993) Reading too soon: How to understand and help the hyperlexic child.  Center for Speech and Language.

Aaron, P.G. (1989). Dyslexia and Hyperlexia: Diagnosis and management of developmental reading disability.  New York: Springer.