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 in Developmental 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 English 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 Comprehension Word Recognition PoorGood Good Poor Dyslexia Non- Specified Mixed Specific Comprehension Deficit
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 Comprehension Word Recognition PoorGood Good Poor Dyslexia Non- Specified Mixed Specific Comprehension Deficit
Figure 4.1 Subtypes Based on Word Recognition and Listening Comprehension Word Recognition PoorGood Good Poor Dyslexia Non- Specified Mixed Specific Comprehension Deficit
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 Comprehension Word Recognition PoorGood Good Poor Dyslexia Non- Specified Mixed Specific Comprehension Deficit
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 Comprehension Word Recognition PoorGood Good Poor Dyslexia Non- Specified Mixed Specific Comprehension Deficit
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 Comprehension Word Recognition PoorGood Good Poor Dyslexia Non- Specified Mixed Specific Comprehension Deficit
A more elaborate classification
Figure 4.2 Subtypes of Reading Disabilities SubtypeListening Comprehension Word Recognition DyslexiaGoodPhonological Surface Rate Disabled MixedPoorPhonological Surface Rate Disabled Specific Comprehension Deficit :PoorPhonological 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