Wake Forest University
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Transcript of Wake Forest University
Wake Forest University
Gallaudet University
Supported by the NIH and NSF
Georgetown University
What Brain Imaging Tells us about Reading Acquisition and Intervention
Guinevere EdenCenter for the Study of Learning
Reading is a Cultural Invention
First use of alphabet - 1800 B.C.
Divination Characters on Oracle BonesShang Dynasty 1400-1100 BC
Bolger et al. (2005)
Alphabetic Logographic
Reading has to be Learned – in Different Ways
Dehaene et al. (2010)
Learning to Read Changes the Brain
Petersson et al. (2007)
LDAH
Brain Imaging
Franz Gall (1758-1828) Phrenology
10 Second Cortical AnatomyTouch
Vision
Hearing
Motor
Dorsal pathway(magnocellular):motionlocationmental rotationspatial relationships
Ventral pathway (parvocellular):formcolorobject identificationface identity
Parallel Visual Pathways
Where
What
Left Hemisphere: Right Hemisphere:Word Form Area Face/Object Area
Kanwisher et al, 1997
Face Processing
Gauthier et al., 1999
Left Hemisphere: Right Hemisphere:Word Form Area Face/Object Area
● Reading Acquisition ● Precocious Reading ● Reading Disability
Learning to Read
• Phases of reading acquisition (Ehri, 1992)
– Pre-alphabetic- visual– Partial alphabetic- phonological cues– Full alphabetic- decoding– Consolidated Alphabetic- chunking,
analogy• Phonological processing abilities are
critical (Wagner and Torgesen, 1987)
Research Questions
• What is the neural basis of visual word
processing in healthy children?
• How does the neural basis of word
processing change during schooling?
• What is the relationship between these
neural systems and phonological skills?
Reading in Typical Children Simos et al., 2001
MEG (MSI)12 Children (8-15 years)16 Adults (23-28 years)Real word recognition
8 year old 28 year old
Increasing left inferior frontal gyrus
Lateralization of infero-temporal cortex
No change in left temporoparietal cortex
The neural basis of reading
• Left inferior frontal gyrus
• Left temporo-parietal cortex
• Left infero-temporal cortex
The neural basis of reading
• Left inferior frontal gyrus
• Left temporo-parietal cortex
• Left infero-temporal cortex
OrthographyDirect Lexical Access
The neural basis of reading
• Left inferior frontal gyrus
• Left temporo-parietal cortex
• Left infero-temporal cortex
Cross-modal integrationPhonological assembly
Semantics
The neural basis of reading
• Left inferior frontal gyrus
• Left temporo-parietal cortex
• Left infero-temporal cortex
SemanticsPhonological assembly
Center for the Study of Learning, Georgetown University
Implicit Word Processing
- =Adapted from Price et al, 1996
41 normal subjects
6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23Male Female
Task PerformanceWords vs. False Fonts
Accuracy Reaction Time
-15
-10
-5
0
5
10
15
20
6 8 10 12 14 16 18 20 22
Age (Years)
Acc
ura
cy D
iffe
ren
ce (
% c
orr
ect)
R2= .00 n.s.
-200
-150
-100
-50
50
100
150
200
6 8 10 12 14 16 18 20 22
Age (Years)
Rea
ctio
n T
ime
Dif
fere
nce
(m
s)
R2= .03 n.s.
0
6- 9.4 yn=13
9.4- 18 yn=13
20- 23 yn=15
Implicit Reading Activity
Turkeltaub et al. Nature Neuroscience, 2003
Developmental Changes in Activity
p< .001, peak p< .0001Reading Composite
fMR
I
Samuel Orton1925
“In the process of early visual education… the storage of memory images of letters and words occurs in both hemispheres…. the process of learning to read entails the elision from the focus of attention of the confusing memory images of the nondominant hemisphere”
Phonology and Reading
• Types of phonological processing (Wagner & Torgesen, 1987)
– Phonological awareness (LAC)– Phonological naming (RAN)– Working memory (Digit Span)
• Subtypes of dyslexia are associated with these types of phonology
• Are these abilities associated with different aspects of reading?
19981998 20002000
National Reading Panel, 2000: Five Component Skills Essential for reading
Phonemic AwarenessPhonemic Awareness
PhonicsPhonics
FluencyFluency
VocabularyVocabulary
Comprehension strategiesComprehension strategies
Identifying words accurately and fluently
Constructing meaning once words are identified
Phonological Awareness
Lindamood Auditory Conceptualization Test (LAC)
“Show me /p/ /t/ /p/”
“If this says ‘eth’,show me ‘ith’
Phonological Naming
Rapid Automatized Naming Test (RAN)
s a o d o p a p d os d a o a p s p d so p s p d o s a o pa d o p s p a s d sp o s d s p o a o d
s a o d o p a p d os d a o a p s p d so p s p d o s a o pa d o p s p a s d sp o s d s p o a o d
Working Memory
Digit Span
“3 8 2 4”“7 4 6 2 5”
“9 2 3 6 1 8”“5 3 8 2 7 4 6”
“2 5 4 3 2 8 9 4”
Correlations with Phonology
Phonological AwarenessPhonological RecodingWorking Memory
p< .005, peak p< .0005
Turkeltaub et al. Nature Neuroscience, 2003
Conclusions
Young Readers Phonology
Young readers activateleft temporoparietalcortex, related to phonological awareness
Conclusions
Young Readers Phonology
Reading Acquisition
Young readers activatetemporoparietal cortex, related to phonologicalawareness
Reading acquisition=
Right posterior cortex(nonlinguistic visual)
Left frontal & temporal(phonology, semantics)
Reading in Children Aged 6 to 9Chinese and American
Data provided by LH Tan Turkeltaub et al., 2003
The neural basis of precocious reading acquisition: fMRI case study
of hyperlexic reading
Hyperlexia
• Developmental disorder of communication (usually autism spectrum)
• Extremely precocious reading learned very early without explicit instruction
• Reading scores above expectation, with comprehension commensurate with verbal ability
• Incidence ≈ 2 / 10,000 (Burd et al., 1985, Yeargin- Allsopp, 2003)
Ethan
• 10-year-old boy• Disordered
– expressive/receptive language (first word at 3.5y)– social interaction– motor coordination
• Pervasive Developmental Disorder- Not Otherwise Specified
• Early intense interest in text• Precocious reading
Ethan’s Reading Scores
Age
5y-11m
9y-9m
Word I.D.
Age eq.
8y-10m
15y-1m
WordAttackAge eq.
9y-4m
16y-11m
GORTPassage
Age eq.
10.3
14.9
GORTComp.Age eq.
<7.9
12.1
Dyslexic vs. Hyperlexic Reading
Words Dyslexic Hyperlexic
11.1 yr 7.0 yr
therapeutic
bouquet
trivialities
Hyperlexia HypothesesLeft Hemisphere
Phonological AdvantageWelsh et al., 1987
Right HemisphereVisual Advantage
Cobrinik, 1982
Methods
• Same fMRI methods as cross sectional study
• Compared Ethan to two control groups– Age Matched (n=9)– Reading Matched (n=8)
Ethan- Implicit Reading
P< .005Turkeltaub et al., Neuron 2004
Ethan vs. ControlsLeft Hemisphere
AgeMatched
(n=9)
ReadingMatched
(n=8)
Correlations with Phonological Awareness
p< .005, peak p< .0005LAC
fMR
I
Ethan vs. ControlsRight Hemisphere
AgeMatched
(n=9)
ReadingMatched
(n=8)
Reading Acquisition
Turkeltaub et al. Neuron, 2004
Hyperlexia HypothesesLeft Hemisphere
Phonological AdvantageWelsh et al., 1987
Right HemisphereVisual Advantage
Cobrinik, 1982
Conclusions
• In contrast to single hemisphere theories, Ethan demonstrated both– Hyper-activity in left hemisphere
phonological areas– Increased activity in right hemisphere
visual areas
• Left temporoparietal cortex is hyper-active in hyperlexia
Reading Research
BasicResearch
TranslationalResearch
Policy and Education
The International Dyslexia Association / NICHD Research
Definition of Dyslexia
Dyslexia is a specific learning disability that is neurological in origin. It is characterized by difficulties with accurate and / or fluent word recognition and by poor spelling and decoding abilities...
The International Dyslexia Association / NICHD Research
Definition of Dyslexia
… These difficulties typically result from a deficit in the phonological component of language that is often unexpected in relation to other cognitive abilities and the provision of effective classroom instruction…
The International Dyslexia Association / NICHD Research
Definition of Dyslexia
… Secondary consequences may include problems in reading comprehension and reduced reading experience that can impede growth of vocabulary and background knowledge.
Developmental Dyslexia
Research•Behavioral Evidence•Anatomical and Physiological
evidence•Genetic evidence
Practice•Early identification•Remediation
Developmental Dyslexia
• 15% of the population is Learning Disabled
• 75-80% or these are Dyslexic
• 5 to 12 % school aged children in the US have basic deficits in reading (IQ discrepant model versus low achievement)
• Males and females a not equally affected
Developmental Dyslexia
• 74% of poor 3rd graders were still impaired when tested in high school
• “Compensated” adult dyslexics still demonstrate measurable underlying problems
• 60% of poor adult readers have undetected or untreated LD
• 50% of juvenile delinquents have undetected LD
Developmental Dyslexia
Research•Behavioral Evidence•Anatomical and Physiological
evidence•Genetic evidence
Practice•Early identification•Remediation
Behavioral Evaluation of Dyslexia
Measurement:
• Single Word Reading
• Phonemic Awareness
• Automatic Naming Speed
• Sequential Working Memory
Behavioral Evaluation of Dyslexia
Measurement:
Single Word Reading
• Phonemic Awareness
• Automatic Naming Speed predictive
• Sequential Working Memory
Behavioral Manifestations of Developmental
Dyslexia• Phonological Processing
– Sound segmentation and manipulation
– Rapid name retrieval– Verbal working memory
Behavioral Manifestations of Developmental
Dyslexia• Phonological Processing
– Sound segmentation and manipulation
– Rapid name retrieval– Verbal working memory
• Sensorimotor Processing– Visual motion processing– Motor coordination– Auditory processing
Ramus, TINS 2004
Eden et al., Nature 1996
Visual Motion Perception: Controls versus Dyslexics
Demb et al.,1997 Proc.Nat.Acad.Sci.
Ramus, TINS 2004
Ramus 2004• Genetically driven focal cortical
abnormalities disrupt processes in the left hemisphere (phonological processing)
• Under certain hormonal conditions these disruptions propagate to the thalamus, leading to sensory impairment
• These disruptions also extend to posterior parietal cortex and cerebellum
Developmental Dyslexia
Research•Behavioral Evidence•Anatomical and Physiological
evidence•Genetic evidence
Practice•Early identification•Remediation
Anatomical VariationsLeftLeft
RightRight
II
IIII
IIIIII
IVIV
VV
VIVI
Galaburda et al. 1985
Neural Basis of Dyslexia: Structural MRI Studies
Findings reported only once
Findings reported more than once
Eckert et al. 2004
Left Hemisphere White Matter Tracts and Dyslexia
• Reduced fractional anisotropy (FA) in L arcuate fasciculus.
• Positive correlation of L arcuate fasciculus FA with PA.
• Positive correlation of L inferior fronto-occipital fasciculus FA with orthographic processing.
Vandermosten et al. 2012
White Matter Studies of DyslexiaChildren
• Compared to Typical Readers– Reduced FA in left IFG (Rimrodt et al., 2010)– Reduced FA in left temporo-parietal WM
(Rimdodt et al., 2010)– Reduced FA of inferior-fronto occipital fasciculus
(Rollins et al., 2009)– Reduced FA of inferior longitudinal fasciculus
(Rollins et al., 2009)– Increased posterior corpus collosum (Hasan et
al., 2012)– Reduced left superior longitudinal fasciculus FA
(Carter et al., 2009)– Abnormal orientation of right superior longitudinal
fasciculus (Carter et al., 2009)
• Correlations – Positive for reading speed and left IFG FA
(Rimrodt et al., 2010)– Positive for posterior corpus collosum mean
diffusivity with word reading and comprehension (Hasan et al., 2012)
– Positive for superior corona radiata and single/pseudoword reading (Odegard et al., 2009)
– Positive for left temporo-parietal WM with reading scores (Niogi and McCandliss, 2006)
Adults• Compared to Typical Readers
– Reduced FA of left arcuate fasciculus (Vandermosten et al., 2012)
– Reduced FA in bilateral temporo-parietal WM (Klingberg et al., 2000)
– Reduced FA bilateral fronto-temporal WM (Steinbrink et al., 2008)
– Reduced FA left temporo-parietal WM (Steinbrink et al., 2008)
• Correlations– Positive for phonemic awareness and
speech perception with FA of left arcuate fasciculus (Vandermosten et al., 2012)
– Positive for left temporo-parietal WM and reading score (Klingberg et al., 2000)
Flowers, Wood, & Naylor, 1991
Typical Readers
Neurobiological Basis of Reading
Typical Readers Dyslexic Readers
Neurobiological Basis of Reading
fixate repeat delete
+ rat rat
rat at
fixation vocalization vocalization +
phonological manipulation
Task
Stimulus
Response
Processes
Phoneme Deletion TASK
Typical Readers: Deletion versus Repetition
left right
Dyslexic Readers: Deletion versus Repetition
left right
Group Comparison: Controls > Dyslexics
left right
Eden et al., Neuron 2004
Controls > Dyslexics
Dyslexia across cultures: same or different?
Same brain region less active in dyslexics during reading tasks in all countries
Paulesu et al., 2001
Developmental Dyslexia
Research•Behavioral Evidence•Anatomical and Physiological
evidence•Genetic evidence
Practice•Early identification•Remediation
Genetic Basis of Dyslexia
• 75 - 100% concordance in monozygotic twins
• 35 - 40% concordance in first degree relatives
• Chromosomes 1, 2, 6, 15 and 18 are implicated in various studies
Developmental Dyslexia
Research•Behavioral Evidence•Anatomical and Physiological
evidence•Genetic evidence
Practice•Early identification•Remediation
Early Identification
Predictive Assessment of Reading (PAR)
Source: Wake Forest University
• Letter and word recognition (correctly pronouncing printed letters and words)
• Phonemic awareness (recognition of specific sounds in a word)
• Naming speed (speed of naming of letters, digits or common objects that are already known)
Early Identification
Predictive Assessment of Reading (PAR)
Source: Wake Forest University
Accuracy of PAR Prediction
20
40
60
80
100
120
140
160
40 60 80 100 120 140 160
PAR Predicted Reading Score
Ac
tua
l WJ
-III
Re
ad
ing
S
co
re
Early Identification of Dyslexia
Comprehensive Test of Phonological Processing (CTOPP)
Early Literacy Screening (NCLD)
Fox in a Box
Predictive Assessment of Reading (PAR)
Phonological Awareness Literacy Screening (PALS)
Test of Word Reading Efficiency (TOWRE)
Test of Phonological Awareness (TOPA)
Texas Primary Reading Inventory
Source: Parenting a Struggling Reader, Hall & Moats
Developmental Dyslexia
Research•Behavioral Evidence•Anatomical and Physiological
evidence•Genetic evidence
Practice•Early identification•Remediation
Remediation Approaches • Phonology and other language structures are explicitly and systematically taught
• Large amount of practice given & small group or one-one
• Use of enhancing techniques (multi-sensory techniques linking listening, speaking, reading, and writing)
Examples of Multisensory Remediation Approaches
Orton-Gillingham Sonday System
Alphabetic Phonics Lindamood-Bell
Slingerland Phonographix
Spaulding
Wilson Language
LANGUAGE!
Project Read
June and Samuel Orton
http://www.interdys.org/
Research and Science Policy
No Child Left Behind Act, Reading First, 2001
• Requires methods that are used in the classroom to teach children how to read to be based upon valid scientific findings
• Based on findings from the National Reading Panel: Meta-analysis of scientific studies on reading that met certain criteria
Institute of Educational SciencesUS Department of Education
Guidelines on how to evaluate whether an educational intervention is supported by rigorous evidence
Randomized controlled trials
+
Effective in two or more settings
= Strong Evidence
Pre-post studies do not comprise “strong” or even “possible evidence” - often produce erroneous results
Institute of Educational SciencesUS Department of Education
Coalition for Evidence-Based Policy
“There are a vast array of educational interventions that claim to improve educational outcomes and to be supported by evidence…
...introduced with great fanfare as being able to produce dramatic gains…
…yielding little in the way of positive and long lasting changes”
-
=
)(
After BeforeIntervention Intervention
Dyslexia-specific brain activation profile becomes normal following successful remedial training
Simos, Fletcher, et al. Neurology,2002
Pretesting Posttesting
Developmental Dyslexia
Research•Behavioral Evidence•Anatomical and Physiological
evidence•Genetic evidence
Practice•Early identification•Remediation
Interval 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
InterventionS
tand
ard
Sco
re
Torgesen, et al., 2001
Study Design• Assignment of individuals into different interventions
• Groups are equal in reading measures prior to the intervention
• Compare the two groups after intervention
Group1 Group 2
Pre intervention
A B
Post intervention
June and Samuel Orton
Adult Phonological Intervention Study
Subjects:• 20 Adults from Orton Center, recruited through Wake Forest University
Intervention:• 112.5 hours of Lindamood-Bell (over 8 weeks)
Before and after measures:
• Behavior: reading, phonemic awareness
• Physiology (fMRI): phonemic segmentation
0.0
2.0
4.0
6.0
8.0
10.0
12.0
14.0
16.0
18.0
20.0
Visual Imagery (SI)
Phonemic Awareness (TAAS)
Per
cen
t C
han
ges
Non-Intervention Group Intervention Group
*p < .05
*
*
0.0
2.0
4.0
6.0
8.0
10.0
12.0
14.0
16.0
18.0
20.0
Visual Imagery (SI)
Phonemic Awareness (TAAS)
Per
cen
t C
han
ges
Non-Intervention Group Intervention GroupNon-Intervention Group Intervention GroupNon-Intervention Group Intervention Group
*p < .05
*
*
Skills Targeted by Intervention
Visual Imagery (SI) Phonemic Awareness (TAAS)
-5.0
0.0
5.0
10.0
15.0
20.0
25.0
30.0
Non-Word Reading (WJWASS)
Phonemic Transfer Index (DST)
Per
cen
t C
han
ge
s
Non-Intervention Group Intervention Group
**
*p < .005
-5.0
0.0
5.0
10.0
15.0
20.0
25.0
30.0
Non-Word Reading (WJWASS)
Phonemic Transfer Index (DST)
Per
cen
t C
han
ge
s
Non-Intervention Group Intervention GroupNon-Intervention Group Intervention GroupNon-Intervention Group Intervention Group
**
*p < .005
Skills Supporting Reading
Non-Word Reading Phonemic Transfer Index(WJWASS) (DST)
-4.0
-2.0
0.0
2.0
4.0
6.0
8.0
10.0
12.0
14.0
Real Word Reading (WRAT)
Reading Accuracy (GORT)
Reading Rate (GORT)
Reading Comprehension(GORT)
Sta
nd
ard
Sco
re C
han
ges
Non-Intervention Group Intervention Group
*
*p < .05
-4.0
-2.0
0.0
2.0
4.0
6.0
8.0
10.0
12.0
14.0
Real Word Reading (WRAT)
Reading Accuracy (GORT)
Reading Rate (GORT)
Reading Comprehension(GORT)
Sta
nd
ard
Sco
re C
han
ges
Non-Intervention Group Intervention GroupNon-Intervention Group Intervention GroupNon-Intervention Group Intervention Group
*
*p < .05
Oral Reading Skills
Real Word Reading Reading Accuracy Reading Rate Reading(WRAT) (GORT) (GORT) Comprehension (GORT)
-
=
)(
After BeforeIntervention Intervention
Intervention No Intervention
Before
After
ANOVA Group x Day: Increases in Activity Following Intervention
left rightEden et al., Neuron 2004
ANOVA Group x Day: Increases in Activity Following Intervention
left rightEden et al., Neuron 2004
Conclusion
• After phonological intervention adults with dyslexia show increased activation in the left and right hemispheres.
• The right hemisphere areas are similar to those in the left hemisphere involved in phonological processing in good readers.
Increases in Activity Following Intervention Children
Left Inferior Frontal Gyrus: increases in children (average 9 years) N=32
Skills Targeted by Intervention
*** p<0.001, ** p<0.01, * p<0.05
***
**
Reading Skills
*** p<0.001, ** p<0.01, * p<0.05
***
***
***
Skills Supporting Reading
*** p<0.001, ** p<0.01, * p<0.05
*
What else changes in the brain?
What’s the matter GRAY MATTER?
Draganski et al., Nature 2004
Research Design
• 11 dyslexic children: reading intervention followed by no instruction
• Anatomical scans obtained at each time point for analysis of gray matter volume
Reading Intervention No Intervention
SCAN1 SCAN 2 SCAN 3
8 weeks 8 weeks
Behavioral Changes After Intervention
Gray Matter Volume Increases After Intervention
Right Cerebellum
Left Fusiform/Hippocampus Right
Hippocampus
Left Precuneus
Percent Change in Gray Matter Volume
•Regions know to be involved in the processing of information from multiple sensory modalities are also involved in reading.
• The neurobiological representation of reading is established early on.
Overall Summary
•Dyslexic individuals show under- activity in these regions, especially parietal cortex.
•Brain activity changes following intensive remediation. Adults and children exhibit different patterns.
•Structural changes are also observed following intervention.
Overall Summary
Who will have the greatest reading gains after the intervention?
Those who show brain activity in inferior parietal cortex prior to the intervention. Activity here is predictive of the amount of reading improvement.
Developmental Dyslexia
Research•Behavioral Evidence•Anatomical and Physiological
evidence•Genetic evidence
Practice•Early identification•Remediation
John AgnewKate CappellEmily CurranEmma ColeIain DeWittErin EinbinderLynn GareauKaren JonesDaniel KooAnthony KrafnickJoe MaisogMartha MirandaAlison MerikangasCorinna MooreEileen NapolielloOlumide OluladeJenni RosenbergPeter TurkeltaubRobert TwomeyJohn VanMeter
Wake Forest UniversityLynn FlowersFrank WoodDebi Hill
Gallaudet UniversityCarol LaSassoKelly Crain
Supported by NSF, NICHD, NIDCD, NIMH
The 63rd International Dyslexia Association Annual Conference
http://www.interdys.org/
http://csl.georgetown.edu