Diagnosing Learning Disabilities

Models to diagnose

Reading Disorder

By: Mike Hogan, Chris Franz, & Ron Teffaine

Canadian Definition of Learning Disabilities (January 30, 2002)

Learning Disabilities (LDs)… affect… individuals… [with] at least average abilities… As such, LDs are distinct from global intellectual deficiency.

LDs result from impairments in one or more processes related to perceiving, thinking, remembering or learning (e.g., language processing, phonological processing, processing speed, memory & attention, executive functions, etc.).

LDs interfere with (1) oral language, (2) reading, (3) written language, and (4) mathematics.

LDs are lifelong… [They] are suggested by unexpected academic under-achievement.

LDs are due to genetic and/or neurobiological factors or injury that alters brain functioning…

DSM-IV-TR LD Model (1994/2000)

Learning Disorders are diagnosed when:– an individual’s achievement in reading,

mathematics, or written expression is substantially below that expected for age, schooling, and level of intelligence (e.g., ≥ 1½ SDs below the mean).

– the learning problems significantly interfere with academic achievement or activities of daily living that require reading, math, or writing skills.

DSM-IV-TR LD Model

Associated Features & Disorders:– Abnormalities in cognitive processing (e.g., visual

perception, linguistic processes, attention, memory, etc.)

– Medical conditions: lead poisoning, fetal alcohol syndrome, fragile X syndrome

– Demoralization, low self-esteem, social skills deficits, increased drop-out rate (1.5 times > average)

– Higher rate of Disruptive Behaviour & Mood Disorders

DSM-IV-TR LD Model

Differential Diagnosis– LDs must be differentiated from:

Normal variations in achievement (< 1 SD below mean)

Lack of opportunity (e.g., poor attendance)Poor teaching (e.g., home schooling)Cultural factors (e.g., EAL)Impaired vision or hearingMental retardation (except Mild cases)

DSM-IV-TR Reading Disorder

Diagnostic Criteria:A. Reading achievement (via individually administered

standardized tests of reading accuracy, speed, or comprehension), is substantially below that expected given the person’s age, measured intelligence, and age-appropriate education.

B. The disturbance in Criterion A sig. interferes with achievement or activities of daily living that require reading.

C. If a sensory deficit is present, the reading difficulties are in excess of those usually associated with it.

Coding Note: If a general medical (e.g., neurological) condition or sensory deficit is present, code the condition of Axis III.

Using the DSM-IV-TR Model

Look for chronic underachievement in reading:– Interview teachers and parents at referral– Observe student’s reading continuum, past running

records, & results from informal reading inventories– Check cumulative file for comments & lower marks in

ELA, as well as failed progress in Reading Recovery and/or Early Literacy Intervention programs

Look for family history of reading problems:– Use background questionnaire &/or interview parents

Using the DSM-IV-TR Model

Rule out competing explanations:– Poor or inconsistent school attendance– Possible EAL status– History of home-schooling– Vision and hearing problems– CDC reports of global developmental delay &/or

below average intellectual level previously found– Little or no home support of literacy

Using The DSM-IV-TR Model

Conduct individual standardized testing:– Aptitude tests (e.g., WISC-IV)– Achievement tests (e.g., WIAT-II/GORT-IV or WIAT-III):

Ensure you have tests of word reading, decoding or word attack, comprehension, and reading fluency

A spelling test facilitates error analysis for sub-typing– Do ability-achievement discrepancy analysis (predicted

achievement > simple difference; sig. at p < .05; use a base rate of 10% or lower for severe LD)

– Include other processing tests that correlate with reading achievement (e.g., PAT, CTOPP, PAL-II – phonological awareness, orthographic awareness, rapid naming, morphological awareness, TOC, SIT, NEPSY-II, etc.)

The Cross-Battery Model of LD(Flanagan, Ortiz, Alfonso & Mascolo, 2006)

Four Level Approach: Level I-ALevel I-A, normative deficit in academic functioning Level I-BLevel I-B, exclusionary factors for academic deficit must be

ruled out Level II-ALevel II-A, normative deficits in cognitive abilities/processes Level II-BLevel II-B, exclusionary factors are ruled out for cognitive

deficits Level IIILevel III, establish consistency between specific cognitive

deficits and specific areas of academic underachievement and otherwise normal functioning in areas unrelated to academic deficits

Level IVLevel IV, evidence of functional limitations in daily activities related to the academic deficit

CHC Consistency Approach to LD Diagnosis

Gf: Inductive (I), and General Sequential Reasoning (RG) play a moderate role in reading comprehension

Gc: Language Development (LD) and Lexical Knowledge (VL), and Listening Ability (LS) play an important role and become increasingly important as students age

Gsm: Memory span is important especially within the context of working memory

Ga: Phonetic Coding or phonological processing is very important during elementary school years

Glr: Naming facility or rapid automatic naming is very important during elementary years

Gs: Processing speed is important during all school years particularly during elementary

Moderate correlation with readingStrong association with reading

Interpreting Results

Dyslexia Subtypes

The universal “Dyslexia Signature” based on fMRI research by Dr. Sally Shaywitz, et al. 1998 & 2002

Dyslexic readers use compensatory systems to read

Sally Shaywitz, Overcoming Dyslexia, 2003

Interpreting Results

Phonological Dyslexia (~ 75%)– (Decoding < reading comprehension) < AVERAGE– Sight word recognition somewhat better than decoding– Reading fluency is typically slow (this may persist

even after remediation)– Primary deficits in phonological awareness (e.g.,

segmentation, deletion, blending, and so on of syllables, phonemes, etc.)

– Often weak in auditory working memory and factual information

– Has trouble spelling phonetically regular words

Interpreting Results

Surface or Orthographic Dyslexia (~ 15%)– Primary deficit in orthographic processing– Decoding better than sight word recognition– Over-reliance on sound/symbol associations– Try to sound out every word (e.g., sign = /sig-en/)– Very slow and laborious reading speed

Interpreting Results

Mixed dyslexia (~10 %)– Involves reading/spelling features of both

phonological and orthographic dyslexia– Severely impaired in reading, and progress will be

very slow– Results in very bizarre error patterns & poor

syllabic representation:– e.g., Advice read as “Exvices”– e.g., Material read as “Mitear”

Rare Reading Disorder Subtypes

Hyperlexia - uncanny ability to decode words despite significant cognitive deficiency. Comprehension very poor. This may be found among those with Autism Spectrum Disorder.

Deep Dyslexia - a reading comprehension disorder characterized by impairments reading words with abstract meanings; but reading more concrete, easily imagined words are intact.

DeJerine Syndrome - dyslexia without dysgraphia. Student has little difficulty writing, though cannot read.

Two Reading Disorder Subtypes Proposed by Dr. Byron Rourke

Phoneme-Grapheme Matching Disorder

Word Finding Disorder

Phoneme-Grapheme Matching Disorder

Key Deficit:Phoneme-grapheme matching problems are paramount (most

often noticed in difficulties in translating graphemes to phonemes)

– Grapheme-to-Phoneme Conversion: Convert a written word (e.g., wharf) to its pronunciation or corresponding sound sequence (e.g., W OW R F) during oral reading task

– Phoneme-Grapheme Conversion: Convert the sound sequence /W OW R F/ to a written form /wharf/ during spelling tasks

PGMD Prognosis

Written spelling of sight words are average Phonological awareness is normal Poor auditory/verbal memory Word decoding is poor, but not as severe as the

phonological core LD group Matching printed to spoken words is poor Written spelling of words not known “by sight” is poor Writing letters and words to dictation is poor Outcomes are much better than the phonologically

impaired LD group

Word-Finding Disorder

Word-finding and verbal-expressive skill deficits, within a context of a wide range of intact skills and abilities (e.g., average phonological awareness and phoneme-grapheme matching skills)

NOTE: The only major deficit is difficulty in accessing their normal store of verbal associations.

Reading and spelling are very poor during the early school years.

Near average or average performance in these areas emerging towards grade 6-to-8.

Arithmetic and math reasoning seen as strengths.

WFD Prognosis

The PAL-II Model of Diagnosing Reading Disabilities

Step 2

Does the child have MR, ASD, Language Disorder, or social emotional disorder

Has the child had insufficient opportunity to learn English?

Does the child have any known genetic disorders or brain injury or disease that affects brain function?

Step 1

1. Obtain a reliable measure of Verbal Comprehension/ Crystallized IQ- WISC-IV, WJ III, KABC-II, DAS-II, etc.

2. Assess the students:- Sight-Word Knowledge (WIAT-II Word Reading; WJ III Letter-Word

Identification)- Reading Comprehension- Spelling- Word Attack (WIAT-II Pseudoword Decoding; WJ III Word Attack)- Reading Fluency (GORT-4; WJ III Reading Fluency)

Step 2

• VIQ > 91? (and)• Any reading or spelling test fall 15 points below the mean?Note: The size of the discrepancy may depend on the amount of specialized instruction

Assess the student’s phonological awareness, orthographic coding, rapid automatic naming (naming facility), and executive abilities (inhibition & switching)

Step 3

Reliable Tests for Step 3

Phonological Awareness•CTOPP•PAT-II•WJ III•PAL-II •NEPSY-II

Orthographic Coding

•PAL-II Receptive Coding

•PAL-II Expressive Coding

Rapid Automatic Naming

•CTOPP

•PAL-II RAN subtests

•NEPSY-II Speeded Naming

Executive Function•Inhibition/Self-Monitoring

•D-KEFS Color-Word Interference•NEPSY-II Inhibition•NEPSY-II Auditory Attention

•Switching Attention or Stimuli/ Self-Monitoring

•NEPSY-II Letter/Number Naming•PAL-II RAS•NEPSY-II Inhibition•D-KEFS Verbal Fluency: Category Switching

Case Study: Estelle 11½ yrs.

Reason for Referral: Reading and spelling problemsTest Battery: WJ III (7 core tests+ 2 optional tests) NEPSY Word Generation WIAT-II Word Reading, Reading Comprehension, & Spelling WJ III ACH Reading Fluency Writing Sample PAL-II

– Phonological Coding (Syllables, Phonemes, & Rimes)– Morphological Coding & Decoding– RAN – RAS– Pseudoword Decoding– Orthographic Coding– Verbal Working Memory: Letters & Words

Note: 25 individual subtests

Estelle’s Assessment Results

Cognitive Ability– GIA/FSIQ= 101– Gc/VIQ= 96– Gf/Gv (PRI)= 109– Long Term Storage/Retrieval (Glr)= 110 – Gsm=118 (Memory Span=109; Working Memory= 122)

– Gs= 78 (Speed of Reasoning=96; Visual Perceptual Speed= 67)

READING/SPELLING ASSESSMENT:Core Tests:

– Word Reading= 85  – Reading Fluency= 86  – Reading Comprehension= 92 – Spelling= 79

Spells phonetically Errors on irregular words (e.g., kome for comb; juce for

juice), some digraphs & blends (e.g., ph, gh), vce rules (kacke for cake), and r-controlled vowels.

– Writing= 75 Weak organization, grammar, idea generation, sequence

of ideas, content, vocabulary

– Average Phonological Awareness (SS= 101)– Average Naming Facility

RAN= 90

– Below Average Orthographic Awareness & Orthographic Working Memory

PAL-II Orthographic Processing Score= 70 NEPSY Word Generation (S & F words): below average PAL-II Verbal Working Memory= 80

– Below Average Word Attack Skills (phonological PAL-II Pseudoword Decoding= 85

– Executive Function (Switching Mental Sets) RAS= <85

Reading-Spelling Processes:

Conclusions

Surface Dyslexia Disorder of Written Expression Recommendations:

– Remedial Strategies: Barton Program (Level II) Precision Reading (fluency & sight word knowledge) Rosner Word Decoding Program (Decoding & Orthographic

Awareness) Orthographic Awareness Activities (PAL-II)

– Adaptations

Thank youAny questions?