Specific Developmental Specific Developmental Dyslexia: Core Problems and Dyslexia: Core Problems and

Effective TreatmentsEffective Treatments

Dr. Joseph K. TorgesenDr. Joseph K. TorgesenFlorida State University and Florida State University and

Florida Center for Reading ResearchFlorida Center for Reading Research

Montag Lecture Series, March, 2014Montag Lecture Series, March, 2014

Issues to be coveredIssues to be covered

1. What percentage of school children in the United 1. What percentage of school children in the United States experience difficulties learning to read?States experience difficulties learning to read?

3. What are the core neurological/psychological 3. What are the core neurological/psychological problems in students with dyslexia?problems in students with dyslexia?

2. Where do children with “specific developmental 2. Where do children with “specific developmental dyslexia” fit within the broader spectrum of all dyslexia” fit within the broader spectrum of all students with reading difficulties? students with reading difficulties?

4. What do we know about effective interventions 4. What do we know about effective interventions for students with dyslexia?for students with dyslexia?

The Nation’s Report Card—Reading

2013

Go to Google and type in “The Nation’s Report

Card”

The size of the problem

2013 results from National Assessment of 2013 results from National Assessment of Educational Progress at 4Educational Progress at 4thth Grade Grade

10 20 30 40 50 60 70 80 90 10010 20 30 40 50 60 70 80 90 100

Percentage of students performing Percentage of students performing below thebelow the BasicBasic Level Level of Proficiency-179,000 students testedof Proficiency-179,000 students tested

PoorPoor

Non-poorNon-poor

WhiteWhite 2121

BlackBlack

HispanicHispanic5050

Percent Percent belowbelow Basic Basic

1717

Socio-cultural diversity

Socio-economic diversity

4747

4848

Alexis-a student with developmental dyslexiaAlexis-a student with developmental dyslexia

Prior to recent discoveries about dyslexia, Prior to recent discoveries about dyslexia, students like Alexis were diagnosed by exclusionstudents like Alexis were diagnosed by exclusion

Alexis has a reading difficulty not caused by:

Low intelligence, or general ability Lack of support, or learning opportunities, at

home Poor instruction Other disabilities like vision or hearing

Made the assumption, that these disabilities were intrinsic to the child, but didn’t know what the intrinsic disability was

A modern definition of DyslexiaA modern definition of Dyslexia

““Dyslexia is a specific learning disability that Dyslexia is a specific learning disability that is neurobiological in origin. It is is neurobiological in origin. It is characterized by difficulties with accurate characterized by difficulties with accurate and/or fluent word recognition and by poor and/or fluent word recognition and by poor spelling and decoding abilities. These spelling and decoding abilities. These difficulties typically result from a deficit in difficulties typically result from a deficit in the phonological component of language the phonological component of language that is often unexpected in relation to other that is often unexpected in relation to other cognitive abilities and the provision of cognitive abilities and the provision of effective classroom instruction.” effective classroom instruction.” (Lyon & (Lyon &

Shaywitz, 2003)Shaywitz, 2003)

1.1. Heritability studies using large twin samples Heritability studies using large twin samples have shown that core reading problems in have shown that core reading problems in children with dyslexia are highly heritablechildren with dyslexia are highly heritable

2. Studies using FMRI have found consistent 2. Studies using FMRI have found consistent differences in brain functioning in samples of differences in brain functioning in samples of dyslexic and non dyslexic students and adultsdyslexic and non dyslexic students and adults

Dyslexia is a specific learning disability that is Dyslexia is a specific learning disability that is neurobiological in origin: neurobiological in origin: categories of categories of evidenceevidence

Temple, 2001, CONB

Visual CortexAuditory

Cortex

Recent Functional Neuroimaging findings on Adults

Neural Response to Intervention

Does the pattern of brain activation change in response to intervention?

8 children with severe dyslexia (7 to 17)

8 week intense phonologically- based intervention (2 hours a day= up to 80 hours of instruction)

Very large improvements in reading ability

Simos et al., Simos et al., NeurologyNeurology, 2002, 2002

Strong activation Strong activation patternpattern

Weak activation Weak activation patternpattern

Decreased activity Decreased activity in right hemispherein right hemisphere Increased activity in Increased activity in

left hemisphereleft hemisphere

Right H.Right H. Left H. Left H. Right H.Right H. Left H. Left H.

Decreased activity Decreased activity in right hemispherein right hemisphere Increased activity in Increased activity in

left hemisphereleft hemisphere

Right H.Right H. Left H. Left H. Right H.Right H. Left H. Left H.

1.1. Heritability studies using large twin samples Heritability studies using large twin samples have shown that core reading problems in have shown that core reading problems in children with dyslexia are highly heritablechildren with dyslexia are highly heritable

2. Studies using FMRI have found consistent 2. Studies using FMRI have found consistent differences in the brain functioning in samples of differences in the brain functioning in samples of dyslexic and non dyslexic studentsdyslexic and non dyslexic students

3. Examinations of the brains of deceased 3. Examinations of the brains of deceased individuals with dyslexia have found subtle individuals with dyslexia have found subtle differences in brain architecture consistent with differences in brain architecture consistent with behaviorally observed differencesbehaviorally observed differences

Dyslexia is a specific learning disability that is Dyslexia is a specific learning disability that is neurobiological in originneurobiological in origin

1. Students with dyslexia show early difficulties learning 1. Students with dyslexia show early difficulties learning letter sound correspondencesletter sound correspondences

It is characterized by It is characterized by difficulties with accurate difficulties with accurate and/or fluent word recognitionand/or fluent word recognition and by poor and by poor spelling and decoding abilities.spelling and decoding abilities.

2. They also have difficulties learning to “sound out” 2. They also have difficulties learning to “sound out” unfamiliar words (phonemic decoding skills)unfamiliar words (phonemic decoding skills)

3. Their difficulties learning to decode unfamiliar words 3. Their difficulties learning to decode unfamiliar words makes them inaccurate readers, and makes their makes them inaccurate readers, and makes their reading slow and labored and unrewardingreading slow and labored and unrewarding

4. They do not become fluent readers because their 4. They do not become fluent readers because their inaccurate and labored decoding makes it difficult to inaccurate and labored decoding makes it difficult to learn to recognize thousands of words by sightlearn to recognize thousands of words by sight

Once reading instruction begins, fluency based word reading Once reading instruction begins, fluency based word reading

tasks are highly diagnostic of the kinds of reading difficulties tasks are highly diagnostic of the kinds of reading difficulties

experienced by students with dyslexiaexperienced by students with dyslexia

Pronounceable nonwords

pim

baf

pate

skree

dreker

brinbert

High frequency read words

cat

book

help

paper

money

space

Before reading instruction begins, students with dyslexia Before reading instruction begins, students with dyslexia have difficulties becoming aware of the have difficulties becoming aware of the phonological phonological structure of languagestructure of language

These difficulties typically result from a deficit These difficulties typically result from a deficit in the in the phonological component of languagephonological component of language that is often unexpected in relation to other that is often unexpected in relation to other cognitive abilities and the provision of cognitive abilities and the provision of effective classroom instruction.”effective classroom instruction.”

big

dig

bog

bin

Words are composed of strings of phonemes. A phoneme is the smallest unit of sound in a word that makes a differences to its identity

Phoneme awareness is the Phoneme awareness is the understandingunderstanding that speech is composed that speech is composed of a sequence of sounds (phonemes) of a sequence of sounds (phonemes) that are combined, and recombined to that are combined, and recombined to form words. It is also the form words. It is also the abilityability to to identify and manipulate these soundsidentify and manipulate these sounds

It is important for learning to readIt is important for learning to read because it because it helps children understand the way that letters helps children understand the way that letters are used to represent words in our languageare used to represent words in our language

In Kindergarten, the two In Kindergarten, the two most diagnosticmost diagnostic tests tests for dyslexia are:for dyslexia are:

Knowledge of letter names or letter soundsKnowledge of letter names or letter sounds

Tests of phonemic awarenessTests of phonemic awareness

““What is the last sound you hear in the word What is the last sound you hear in the word manman??

““What are the sounds in the word What are the sounds in the word fitfit??

““If the word If the word manman began with an /f/ sound, what word began with an /f/ sound, what word would it be?would it be?

The Basic Discovery: A summaryThe Basic Discovery: A summary

Specific reading disabilities, or developmental Specific reading disabilities, or developmental dyslexia, is caused by a weakness, or lack of dyslexia, is caused by a weakness, or lack of talent, in the talent, in the phonological domain of languagephonological domain of language

This weakness makes it difficult to acquire This weakness makes it difficult to acquire phonemic awareness and alphabetic reading phonemic awareness and alphabetic reading skills—which interferes with the growth of skills—which interferes with the growth of accurate reading skills and reading fluency. accurate reading skills and reading fluency. These problems, in turn, interfere with reading These problems, in turn, interfere with reading comprehensioncomprehension

What we know about the factors that What we know about the factors that affect reading comprehensionaffect reading comprehension

Proficient comprehension of text is influenced by:Proficient comprehension of text is influenced by:

Accurate and fluent word reading skillsAccurate and fluent word reading skills

Oral language skills (vocabulary, linguistic comprehension)Oral language skills (vocabulary, linguistic comprehension)

Extent of conceptual and factual knowledgeExtent of conceptual and factual knowledge

Knowledge and skill in use of cognitive strategies to Knowledge and skill in use of cognitive strategies to improve comprehension or repair it when it breaks down.improve comprehension or repair it when it breaks down.

Reasoning and inferential skillsReasoning and inferential skills

Motivation to understand and interest in task and Motivation to understand and interest in task and materialsmaterials

Important facts about talent in the Important facts about talent in the phonological language domain:phonological language domain:

It is like most other talents in that it is It is like most other talents in that it is distributed distributed normallynormally in the population in the population

“Phonological talent” is normally distributed in the population

100

50th

85

16th

70

2nd

130

98th

115

84th

Standard Scores

Percentile Ranks

Children can be strong in this talent-like my grandson Andrew

“Phonological ability” is normally distributed in the population

100

50th

85

16th

70

2nd

130

98th

115

84th

Standard Scores

Percentile Ranks

Children can be moderately weak in this talent-like David

Each of these kinds of weakness is normally distributed in the population

100

50th

85

16th

70

2nd

130

98th

115

84th

Standard Scores

Percentile Ranks

Serious difficulties-probably require special interventions and a lot of extra support-like Alexis

Another important fact about talent in the Another important fact about talent in the phonological language domain:phonological language domain:

It is only weakly correlated with broad It is only weakly correlated with broad verbal ability or general intelligenceverbal ability or general intelligence

Phonological Language Ability is not highly Correlated with General Verbal Ability as measured by IQ tests

Verbal Intelligence

Pho

nolo

gica

l A

bilit

y

Low High

High

Low

Dyslexic

Phonological Language Ability is not highly Correlated with General Verbal Ability as measured by IQ tests

Verbal Intelligence

Pho

nolo

gica

l A

bilit

y

Low High

High

Low

Dyslexic

One more important fact about talent in One more important fact about talent in the phonological language domain:the phonological language domain:

Children’s ability in this area when they Children’s ability in this area when they come to school is influenced both by come to school is influenced both by

biologically based talent, and by biologically based talent, and by opportunities to learn from their pre-opportunities to learn from their pre-

school environmentschool environment

Development of Phonological Development of Phonological SensitivitySensitivity

Cross-sectional study comparing Cross-sectional study comparing the performance of 250 the performance of 250

children from higher income children from higher income families to 170 children from families to 170 children from

lower income families.lower income families.

Children were between two- Children were between two- and five-years of age.and five-years of age.

To summarize:To summarize:

Children can come to school weak in Children can come to school weak in phonological ability phonological ability either because of their either because of their biology or their language experiencebiology or their language experience

Regardless of whether they also have Regardless of whether they also have broader weaknesses in verbal ability, broader weaknesses in verbal ability, both both types of children need similar intensive early types of children need similar intensive early reading support in order to prevent reading reading support in order to prevent reading failurefailure

Do we know how to prevent the Do we know how to prevent the phonological problems in students with phonological problems in students with dyslexia from developing into a serious dyslexia from developing into a serious reading disability? reading disability?

Yes, in all but a very small percentage Yes, in all but a very small percentage of students (perhaps around one to two of students (perhaps around one to two percentpercent

An Example of an An Example of an Effective Effective

IntervententionInterventention

Design of Study in which intervention occurredDesign of Study in which intervention occurred1. Most “at risk” first graders from five elementary school - 1. Most “at risk” first graders from five elementary school -

PPVT above 70PPVT above 70

2.Instruction provided in 45 min. sessions every day from 2.Instruction provided in 45 min. sessions every day from October through May in groups of 3 or 5 by experienced October through May in groups of 3 or 5 by experienced teachers or well-trained paraprofessionals teachers or well-trained paraprofessionals

3. Used a structured (scripted) reading program that 3. Used a structured (scripted) reading program that contained instruction and practice in phonemic contained instruction and practice in phonemic awareness, phonics, fluency, and comprehensionawareness, phonics, fluency, and comprehension

30

70 75th

50th

25th

October January May

Nati

on

al

Perc

en

tile

Growth in Word Reading Ability

Oct Nov Dec Jan Feb Mar Apr May

Growth in Correct Words Per Minute on First Grade Level Passages for four lowest performers

60

55

50

45

40

35

30

25

20

15

10

55.7

22211715

What about remediation for What about remediation for older students who did not get older students who did not get

effective preventive effective preventive interventions?interventions?

A study of intensive, highly skilled intervention with A study of intensive, highly skilled intervention with 60 children who had severe reading disabilities60 children who had severe reading disabilities

Children were between 8 and 10 years of ageChildren were between 8 and 10 years of age

Had been receiving special education services for an average of Had been receiving special education services for an average of 16 months16 monthsNominated as worst readers: at least 1.5 S.D’s below grade levelNominated as worst readers: at least 1.5 S.D’s below grade level

Average Word Attack=69, Word Identification=69, Verbal IQ=93Average Word Attack=69, Word Identification=69, Verbal IQ=93

Randomly assigned to two instructional conditions that both Randomly assigned to two instructional conditions that both taught “phonics” explicitly, but used different procedures with taught “phonics” explicitly, but used different procedures with different emphasisdifferent emphasisChildren in both conditions received 67.5 hours of one-on-one Children in both conditions received 67.5 hours of one-on-one instruction, 2 hours a day for 8 weeksinstruction, 2 hours a day for 8 weeks

Children were followed for two years after the intervention was Children were followed for two years after the intervention was completedcompleted

Interval in Months Between Measurements

P-Pretest Pre Post 1 year 2 year

75

80

85

90

95

LIPS

EP

Growth in Total Reading Skill Before, During, and Following Intensive Intervention

Sta

ndar

d S

core

Interval in Months Between Measurements

P-Pretest Pre Post 1 year 2 year

75

80

85

90

95

LIPS

EP

Growth in Total Reading Skill Before, During, and Following Intensive Intervention

Sta

ndar

d S

core

Growth in phonemic decoding during intervention & follow-up

60

70

80

100

Pretest posttest 1 year 2 years

Sta

nd

ard

S

core

90

LIPS

EP

Growth in text reading accuracy during intervention & follow-up

60

70

80

100

Pretest posttest 1 year 2 years

Sta

nd

ard

S

core

90LIPS

EP

Growth in comprehension during intervention & follow-up

60

70

80

100

Pretest posttest 1 year 2 years

Sta

nd

ard

S

core

90

LIPSEP

Growth in fluency during intervention & follow-up

60

70

80

100

Pretest posttest 1 year 2 years

Sta

nd

ard

S

core

90

LIPSEP

Oral Reading Fluency was much improved on passages for which level of difficulty remained constantAbsolute change in rate from pretest to 2-year follow-up.Most difficult passage

Prestest -- 38 WPM, 10 errors

Posttest -- 101 WMP, 2 errors

Next most difficult passage

Pretest -- 42 WPM, 6 errors

Posttest -- 104 WPM, 1 error

Disparity in outcomes for rate vs. accuracy in five remediation studies

70

80

90

100

Sta

nd

ard

Sco

r e

2nd 2nd 10th 10th Prev. 1 Prev.2

Accuracy

Rate

Beginning level of Word Identification Skill

Five principles of effective Five principles of effective intervention for older students with intervention for older students with dyslexia who continue to struggle dyslexia who continue to struggle

in readingin reading

Principle # 1Principle # 1Effective interventions teach academic skills directly

Training in motor, visual, neural, or cognitive processes Training in motor, visual, neural, or cognitive processes without academic contentwithout academic content does does notnot reliably lead to better reliably lead to better academic outcomes for children with learning disabilities academic outcomes for children with learning disabilities (Fletcher et al., 2007).(Fletcher et al., 2007).

Intensive and skillful phonologically based interventions have Intensive and skillful phonologically based interventions have an impact on brain functioning. They facilitate the an impact on brain functioning. They facilitate the development of neural systems that support skilled readingdevelopment of neural systems that support skilled reading

Principle # 2Principle # 2Address learning deficits directly. Teach the skills and knowledge required for proficient reading

Children with auditory processing difficulties need to Children with auditory processing difficulties need to learn how to decode; students who lack fluency need to learn how to decode; students who lack fluency need to become more fluent; students with weak become more fluent; students with weak comprehension/reading strategies need to become comprehension/reading strategies need to become more strategicmore strategic

Principle # 3Principle # 3Broad methods of effective teaching for any struggling learner are helpful for students with dyslexia

Provide clearer and more detailed explanations

Contain more systematic instructional sequences

Provide more extensive opportunities for guided practice

Contain more opportunities for error correction and feedback

Be more precisely targeted at the right level

In contrast to instruction for students who learn easily, interventions for students with dyslexia must:

Allow cumulative review of previously taught content

Principle # 4Principle # 4Provide more intensive instruction

The most direct way to increase learning rate is to The most direct way to increase learning rate is to increase the intensity of instruction. Intensity can be increase the intensity of instruction. Intensity can be increased both by providing additional time and increased both by providing additional time and reducing the size of instructional groupreducing the size of instructional group

Torgesen, 2005aTorgesen, 2005a

Principle # 5Principle # 5Teach students to be strategic for word analysis, vocabulary building, and comprehension

Dyslexic students need to acquire effective strategies Dyslexic students need to acquire effective strategies for decoding complex, unfamiliar words, for learning new for decoding complex, unfamiliar words, for learning new word meanings, and for creating meaning from textword meanings, and for creating meaning from text

Instruction should also explicitly address generalization Instruction should also explicitly address generalization to real literacy/learning tasks in classroom and hometo real literacy/learning tasks in classroom and home

Maureen Lovett (2008)Maureen Lovett (2008)

Questions/Discussion