reading difficulties: research and treatment associate professor genevieve mcarthur arc australian...

Reading difficulties: Research and

treatment

Associate Professor Genevieve McArthur

ARC Australian Research Fellow

(Macquarie Centre for Cognitive Science)

ARC Centre for Cognition and its Disorders

Making evidence-based decisions about the diagnosis and

treatment of dyslexia

Outline

The importance of reviewing the scientific evidence: Data collection

The diagnosis of dyslexia

different ways to diagnosis of dyslexia

myths about dyslexia

how to make an evidence-based diagnosis of dyslexia

Treatments for dyslexia

how to make an evidence-based decision about treatment

“causal” treatments

reading treatments

The importance of reviewing the scientific evidence: The Results

The importance of scientific evidence

Which of these statements – commonly made in the media – are supported by the weight of scientific evidence? True = 1 False = 2

1.You should floss your teeth to reduce tooth decay and gum disease

2.You should take a regular dose of vitamin C to prevent colds

3.You should get a flu shot

4.You should reduce your salt intake to improve your blood pressure

5.You should eat a high-fibre diet to prevent colon cancer

6.You should take gingko to prevent dementia

7.You should drink at least eight glasses of water per day (tea and coffee does not count)

8.You should drink red wine - but not white wine or beer

9.You should stretch before or after exercise to prevent muscle soreness

Outline

The importance of scientific evidence: Data collection

The diagnosis of dyslexia

different ways to diagnosis of dyslexia

myths about dyslexia

how to make an evidence-based diagnosis of dyslexia

Treatments for dyslexia

how to make an evidence-based decision about treatment

“causal” treatments

reading treatments

The importance of scientific evidence: The Results

✓

Research DSM4 Response to Intervention

Descriptive

What is impaired?

Reading ReadingSensation ~AcademiaEveryday reading

ReadingResponse to intervention

Reading

What is unimpaired?

NVIQSensationEducationNeurologyLanguage ~

IQEducation

Diagnostic tests

ReadingNVIQHearingVisionEducation historyLanguage ~

ReadingIQHearingVisionAcademiaEveryday readingEducation history

ReadingResponse to intervention

Reading

Different ways to diagnose dyslexia

Myths about dyslexia

More boys than girls have dyslexia

If you reverse letters (d for b or p) then you have dyslexia

People with dyslexia are more likely to be left-handed

People with dyslexia are unusually intelligent

People with dyslexia are unusually artistic

So … how are you supposed to diagnose dyslexia?

Use an evidence-based model of reading

regular words:

BOOTSee word

‘boot’Spoken word production

Letter identification 1

8007BOOT

P D D LB O O TLetter identification 2

B-O-O-TB-OO-TParsing

‘p’ ‘u’ ‘b’‘b’ ‘oo’ ‘t’Letter-sounds

‘b’ ‘oot’‘boot’Blending

‘fruit’‘boot’Spoken word planning

irregular words:

BOOKSee word

“book”Spoken word production

Letter identification 1

BOOK

B O O KLetter identification 2

B-OO-KParsing

’b oo kLetter-sounds

’ ‘book’Blending

‘book’Spoken word planning

“book”

BOOK Written word rep

‘book’

‘book’ Spoken word rep

Meaning

See word

Spoken word production

Letter identification 1

Letter identification 2

Parsing

Letter-sounds

Blending

Spoken word planning

Written word rep

Spoken word rep

Word meaning

Lexic

al

Sig

ht-

word N

onle

xica

lPhonics

to read regular and irregular words you need:two reading routesthat work at the same timethat work equally well

See word

Spoken word production

Letter identification 1

Letter identification 2

Parsing

Letter-sounds

Blending

Spoken word planning

Written word rep

Spoken word rep

Word meaning

Lexic

al

Sig

ht-

word N

onle

xica

lPhonics

but sometimes they don’t:

but bad at phonics reading (nonlexical) =

phonological dyslexia

some good at sight-word reading (lexical)

but bad at sight-word reading (lexical)=

surface dyslexia

some good at phonics reading (nonlexical)

many bad at sight-word reading (lexical)

and bad at phonics reading (nonlexical)=

mixed dyslexia

See word

Spoken word production

Letter identification 1

Letter identification 2

Parsing

Letter-sounds

Blending

Spoken word planning

Written word rep

Spoken word rep

Word meaning

Lexic

al

Sig

ht-

word N

onle

xica

lPhonics

Irregular-word

Reading CC2

Non-word

Reading CC2

need to assess:two reading routes

CC2 www.motif.org.aueach component

✗✗✗

Outline

The importance of scientific evidence: Data collection

The diagnosis of dyslexia

different ways to diagnosis of dyslexia

myths about dyslexia

how to make an evidence-based diagnosis of dyslexia

Treatments for dyslexia

“causal” and reading treatments

how to make an evidence-based decision about treatment

an evaluation of “causal” and reading treatments

The importance of scientific evidence: The Results

✓

✓

Commercial treatments for dyslexia

“Causal” treatments Reading treatments

Dorothy Bishop

dystalk.com/talks/60-evaluating-alternative-solutions-for-dyslexia

Introductions to evidence-based decisions about treatment

Ben Goldacre

http://www.youtube.com/watch?v=O1Q3jZw4FGs

Step 1: Find a systematic review

Review of all properly controlled studies of a treatment

Done by an independent expert

not a journalist

not a private company

not connected with the company (e.g., Rod Nicolson and Dore)

Some sources

Cochrane Reviews

Google Scholar

Google

What Works Clearinghouse ~

MUSEC Briefings

Step 2: DIY systematic review

Coltheart, M., & McArthur, G. M. (In Press). Neuroscience, education and educational efficacy research. In M. Anderson and S. D.Sala (Eds.), Education in Neuroscience Oxford, UK: Oxford University Press.http://deevybee.blogspot.com/2010/08/three-ways-to-improve-cognitive-test.html

no control group

control group

Significantly bigger reading gains in

treated group than control group

No difference in reading gains in

treated and control groups

Large gains in reading scores in the

treated group

Small gains in reading scores in the

treated group

Step 3: Use indirect evidence

e.g. Eye Q > reading

Evidence that the same type of treatment (other brand) improves

reading

Evidence that the treatment itself (Eye Q) improves a factor (fatty

acids) that has been scientifically proven to improve reading

Evidence that the same type of treatment (other brand) improves

a factor (fatty acids) that has been scientifically proven to

improve reading

Coltheart, M., & McArthur, G. M. (In Press). Neuroscience, education and educational efficacy research. In M. Anderson and S. D.Sala (Eds.), Education in Neuroscience Oxford, UK: Oxford University Press.

Step 4: Ignore brain data

Brain data cannot tell us if an educational treatment works or not

Focus on the behavioural evidence (i.e., reading behaviour)

If a program did not improve reading but did change the brain, would you pay good money to buy it?

If a program did improve reading but did not change the brain, would you not buy it?

Coltheart, M., & McArthur, G. M. (In Press). Neuroscience, education and educational efficacy research. In M. Anderson and S. D.Sala (Eds.), Education in Neuroscience Oxford, UK: Oxford University Press.

Step 5: Ignore anecdotes

Biased sample

Subjective data

Cognitive dissonance

Coltheart, M., & McArthur, G. M. (In Press). Neuroscience, education and educational efficacy research. In M. Anderson and S. D.Sala (Eds.), Education in Neuroscience Oxford, UK: Oxford University Press.

Commercial treatments for dyslexia

“Causal” treatments Reading treatments

Program 1. Systematic review

2. DIY review 3. Indirect evidence

NA 2 studiesReading not tested

The effect of PA on reading contentious

Strong et al. 2010~ 10 studiesNo effect

Hyatt et al. 2009A few studiesNo effect

Bishop 2007A few studiesNo effect

NA NA Working memory can be trained but its effect on reading unknown

Hyatt 2007A few studiesNo effect

Program 1. Systematic review

2. DIY review 3. Indirect evidence

NA NA Phonics has small to moderate effect on dyslexia

NA NA Phonics has small to moderate effect on dyslexia

WWCA few studiesSmall effect

NA NA Phonics has small to moderate effect on dyslexia

NA NA Phonics has small to moderate effect on dyslexia

Outline

The importance of scientific evidence: Data collection

The diagnosis of dyslexia

different ways to diagnosis of dyslexia

myths about dyslexia

how to make an evidence-based diagnosis of dyslexia

Treatments for dyslexia

how to make an evidence-based decision about treatment

“causal” treatments

reading treatments

The importance of scientific evidence: The Results

✓

✓

✓

Which of these statements – commonly made by the media – are supported by the weight of scientific evidence? True = 1 False = 2

1. You should floss your teeth to reduce tooth decay and gum disease

2. You should take a regular dose of vitamin C to prevent colds

3. You should get a flu shot

4. You should reduce your salt intake to improve your blood pressure

5. You should eat a high-fibre diet to prevent colon cancer

6. You should take gingko to prevent dementia

7. You should drink at least eight glasses of water per day (tea and coffee does not count)

8. You should drink red wine - but not white wine or beer

9. You should stretch before or after exercise to prevent muscle soreness

The importance of evidence: The evidence

✗✗

✗

✗✗

✗

✗✗

✗

This above all: to the scientific evidence be true,

and it must follow, as the night the day,

thou are less likely to be false to any man (or woman or child)

(Shakespeare … kind of)

Thank you