Reading Disabilities

Terminolgy

• Congenital word blindness• Dyslexia• Developmental dyslexia• Specific reading disability• Reading disability• Disability-disorder, impairment,

retardation• Language-learning disability (spoken

and written disability)• Development versus acquired

Terminology

• Learning disabled – used to categorize children with reading disabilities

• Language-learning disability just as broad as the previous label

• Places attention on language basis of many learning problems

• Reading disabilities – used with heterogenous groups of children with difficulty reading

Brain Studies

Language differences in Developmental Dyslexia

• Similar patterns of brain activity suggest common impairment across languages

• If deficient phonological processing underlies dyslexia in all languages, the prevalence of dyslexia would tend to be greater in languages with deep orthography (ie. More complicated mappings between orthography and phonology.

Reading and other languages

• See chart in handout.

Language differences inDevelopmental Dyslexia

• Prevalence is two times greater for English than Italian speakers.

• Italian has a shallow orthography, and English has a deep orthography

• Orthographic Patterns Phonemes Italian 33 25 English 1120 46

• boot, two, through /u/• ate, bait, eight, lay /e/

Dyslexia and Gender

Shaywitz et al., 1990

Dyslexia and Gender

• Data has been proven to be biased• Actual reading scores show no

significance between genders

Exclusionary Factors

“Dyslexia is a disorder manifested by difficulty learning to read despite conventional instruction, adequate intelligence, and socio-cultural opportunity. It is dependent upon cognitive disabilities which are frequently of constitutional origin”

World Federation of Neurology

Exclusionary Factors

• Sensory/Emotional/Neurological Factors

• Instructional Factors• Intelligence – problematic with

measurements

Inclusionary Factors

Research Comm. Of the International Dyslexia Association Working Definition

Dyslexia is:• Language-based• Difficulties: single word decoding, insufficient

phonological processing• Difficulties unexpected in relation to age, cognition

and academics• Not the result of dev. Disability or sensory

deprivation• Includes a problem with writing and spelling

Children with dyslexia

Have problems

Using the phonological route to decode words, which results in difficulty recognizing novel words and building of sight vocabulary.

Problems with writing and spelling.

Dyslexia

Is Language-based disability

Insufficient phonological processing underlies the difficulty dyslexics have in learning to read, write and spell.

The books definition

Dyslexia is a developmental language disorder whose defining characteristic is difficulty in phonological processing. The disorder, which is often genetically transmitted is generally present at birth and persists throughout the lifespan. Phonological processing difficulties include storing, retrieving, and using phonological codes in memory as well as deficits in phonological awareness and speech production. A prominent characteristic of the disorder in school-age children is difficulties learning to decode and spell printed words. These difficulties, in turn, often lead to deficits in reading comprehension and writing.

Developmental Characteristics - Preschool

• Begins early in life and continues forever

• In preschool, manifests itself with limited spoken language development (different parameters)

• Primary difficulty is phonological processing

• Difficulties with other aspects of phonological processing: storage and retrieval, speech perception, complex phonological production

Characteristics – School age and adult

• Problems decoding printed words• Spelling difficulties• Secondary to above problems are

reading comprehension

Language-Learning Disabilities

• Dyslexia is not the only language-based reading disability

• As many as 50% of poor readers have language deficits beyond phonological processing

• Problems: vocabulary, morphology, syntax, text-level processing

Characteristics

• LLD deficits in vocabulary and grammar• Phonological processing similar to

dyslexia• Listening comprehension, discourse,

narrative production• Learning to read, word recognition,

reading comprehension• Children with LLD have broad-based

problems in comprehension-this is different to dyslexia.

Classification of Reading Disabilities

• Two major classifications• Dyslexia – word recognition• Language-learning disability – word

recognition and language comprehension

Figure 4.1 Subtypes Based on Word Recognition and Listening

ComprehensionWord Recognition

Poor Good

Good

Poor

DyslexiaNon-Specified

MixedSpecificComprehensionDeficit

Subclassifications

• Dyslexic group – poor word recognition but good listening comprehension

• Mixed – poor word recognition and poor listening comprehension

• Specific Comp Deficit – good word recognition but poor listening comprehension

Subclassifications

• All three have reading comp. problems but for different reasons• Dyslexia – inaccurate and/or slow

decoding skills• Specific Com deficit – language and

cognitive deficits• Mixed – both word recognition and

listening comprehension

Interaction between reading and comprehension

Across grades..• Initially word recognition and listening

comprehension are largely independent, each comprised of a distinct set of cognitive processes

• Over time, deficits in one area may influence in the other, specifically prolonged deficits in word recognition could adversely influence children’s listening comprehension abilities

Subtypes based on nature of word recognition deficits

• Reading styles – • evidence is not compelling that

children can be divided into global (sight word) versus analytical (phonics)learners

The Simple View of Reading

• Word Recognition - decode• Listening Comprehension - understand

Figure 4.1 Subtypes Based on Word Recognition and Listening

ComprehensionWord Recognition

Poor Good

Good

Poor

DyslexiaNon-Specified

MixedSpecificComprehensionDeficit

Figure 4.1 Subtypes Based on Word Recognition and Listening

ComprehensionWord Recognition

Poor Good

Good

Poor

DyslexiaNon-Specified

MixedSpecificComprehensionDeficit

Dyslexia

• Have• Difficulties learning to decode words • Difficulties developing sight-word vocabulary• Listening comprehension abilities within normal range

• Some may have exceptional listening comprehension that help them compensate

• Often missed in untimed tests if they have better listening comprehension skills.

• May also include those children that have phonological processing abilities, since they play an important role on word recognition

Figure 4.1 Subtypes Based on Word Recognition and Listening

ComprehensionWord Recognition

Poor Good

Good

Poor

DyslexiaNon-Specified

MixedSpecificComprehensionDeficit

Mixed Subtype

• They • May fail to meet the IQ-achievement discrepancy

criterion for dyslexia• Have similar word recognition problems like dyslexia• Unlike dyslexia, they have significant difficulties with

language comprehension• Have problems with global cognitive deficits (verbal

and non-verbal processing)• Or maybe just language processing with normal non-

verbal abilities• Deficits in vocabulary, morphosyntax, text-level

processing

Figure 4.1 Subtypes Based on Word Recognition and Listening

ComprehensionWord Recognition

Poor Good

Good

Poor

DyslexiaNon-Specified

MixedSpecificComprehensionDeficit

Specific Comprehension Subtype

• These children have• Exceptional phonological decoding skills, or• Good sight-word reading abilities but not at the same

level as phonolgical decoding skills• Impairments of spoken languages – listening

comprehension such as semantic and syntactic processing

Figure 4.1 Subtypes Based on Word Recognition and Listening

ComprehensionWord Recognition

Poor Good

Good

Poor

DyslexiaNon-Specified

MixedSpecificComprehensionDeficit

A more elaborate classification

Figure 4.2 Subtypes of Reading Disabilities

Subtype ListeningComprehension

WordRecognition

Dyslexia Good Phonological

Surface

Rate Disabled

Mixed Poor Phonological

Surface

Rate Disabled

SpecificComprehension

Deficit

:Poor Phonological

Surface

Rate Disabled

Phonological

• Problems with phonological decoding• Identified on the basis of their problems pronouncing

nonword (zun)• They must sound out using sound-letter

correspondence, not visually recognized• Difficulties reading nonwords as compared to real

words, responses are typical real words visually similar to the target words

• Greater facility recognizing content words as opposed to function words.

• True developmental disorder• Problems with phonological awareness, working

memory and syntactic processing

Surface problems

• Problems reading through the visual route as opposed to the phonological route.

• They misread exception words. They will read talc for talk, or spell laugh as laf

• Show a developmental lag• Their non-word and exception word reading

is like younger children• Seem to take longer to learn to read

Phonological and Visual Routes

• Phonological route• Visual route

Rate (Speed) and Accuracy

• Accuracy-disabled• Rate-disabled

Accuracy-Disabled Readers

• Scores 1.6 years below grade on at least 4/5 word recognition measures

• Produce more errors• Read slower• Poorer comprehension• Lack basic knowledge of sound-letter

correspondence• Oral language – deficits in morphological and

synctactic abilities• Slower in naming serial-letter arrays and

analyzing individual speech sounds

Rate-Disabled versus Accuracy-Disabled Readers

• Marked deficit in reading rate despite grade-appropriate decoding ability

• Scored close to or at grade level on 4+ measure of word recognition and Scores 1.6 years below grade on at least 4/5 speed reading measures

• Good at phonetic identifying regular and exception words (phonetic decoding and sight-word reading) Accurate in word recognition

• Problems with word recognition speed (problems processing large units of text) – slow reading rate

• Oral abilities – no problems except lower on tasks measuring rapid automatic naming.

• Sometimes appear to develop well in primary grades, but problems with advanced reading material

Hard vs. Soft Subtypes

• Surface dyslexics –• Show a developmental lag• Do not display deviant reading abilities• Their nonword and exception word reading is like

younger normal children

• Phonological dyslexics• Different pattern of performance when compared to

younger normal children• Performed less well than the reading level matched

chilren on tests of phonological awareness, working memory, and syntactic processing.

Rate-Disabled versus Accuracy-Disabled Readers

• Two other types of reading disabilities• Accuracy-disabled children

• Children with significant problems in decoding accuracy

• Scores 1.6 years below grade on at least 4/5 word recognition measures

• Produce more errors• Read slower• Poorer comprehension• Lack basic knowledge of sound-letter correspondence• Oral language – deficits in morphological and

synctactic abilities• Slower in naming serial-letter arrays and analyzing

individual speech sounds

Rate-Disabled versus Accuracy-Disabled Readers

• Rate-disabled children• Marked deficit in reading rate despite grade-

appropriate decoding ability• Scored close to or at grade level on 4+ measure of

word recognition and Scores 1.6 years below grade on at least 4/5 speed reading measures

• Good at phonetic identifying regular and exception words (phonetic decoding and sight-word reading) Accurate in word recognition

• Problems with word recognition speed (problems processing large units of text) – slow reading rate

• Oral abilities – no problems except lower on tasks measuring rapid automatic naming.

• Sometimes appear to develop well in primary grades, but problems with advanced reading material