Assessment and Treatment of Reading Disorders: A … Brunsdon.pdf · Reading Disorders: A Cognitive...

transcript

Brunsdon & Coltheart, 2005

Assessment and Treatment of Reading Disorders:

A Cognitive Neuropsychological Perspective

DeCog Research Unit (Developmental Cognitive Neuropsychology Research Unit)

MACCS, Macquarie University

Rehabilitation and Psychology Departments, The Children’s Hospital at Westmead

Overview

! Assessment of reading! Diagnosis of reading impairment ! Treatment of reading difficulties

LetterIdentification

SUBLEXICAL

Visual Word Recognition

LEXICAL

Spoken Word Production

Speech

Letter to Sound ConversionSemantics

Dual Route Model of Reading

! Skilled readers use two main procedures for reading aloud

• Lexical Reading Route• relies on whole-word recognition and allows successful

and efficient processing of words that are familiar to the reader

• Sublexical Reading Route• involves rule-based letter to sound conversion and allows

the skilled reader to ‘sound-out’ unfamiliar words and nonwords.

Developmental Dyslexia

! Developmental Dyslexia is heterogeneous

! Main Subtypes

• Phonological• Surface• Mixed

Developmental Dyslexia - Subtypes

! Phonological Dyslexia• children who have difficulty acquiring skills

for converting letters into sounds

Phonological Dyslexia

! Phonological Dyslexia

• Difficulty with the Sublexical Reading Route • the route that relies on letter to sound correspondences

to assemble a pronunciation.

• Over-reliance on the Lexical Reading Route• the route that relies on whole word recognition

• where the reader gains access to an internal store of the visual representations of familiar words

SUBLEXICAL

LEXICAL

Speech

PhonologicalDyslexia

! Phonological Dyslexia:

• good reading of familiar words• Poor nonword reading• Difficulty reading unfamiliar word• Nonword reading errors

• visual similar real words• eg. tapple → table

Developmental Dyslexia - Subtypes

! Surface Dyslexia• children who have difficulty learning to

recognise words as whole units

Surface Dyslexia

! Surface Dyslexia

• Difficulties with Lexical Reading Route• the route that relies on whole word recognition

• Over-reliance on the Sublexical Reading Route

• the route that relies on letter to sound correspondences to assemble a pronunciation.

LEXICAL

SUB LEXICAL

Speech

Surface Dyslexia

! Surface Dyslexia:

• good nonword reading• good reading of regular words (e.g., little)• poor reading of irregular words (eg. quay)• regularisation errors when reading

• eg. quay → “kway”colonel → “kollonell”

Assessment

! Assessment of phonological, surface and mixed dyslexia in children:

• Standardised word reading tasks inadequate (eg. WRAT, WIAT)

• Only diagnose delay in general reading development

• Do not detect specific types of dyslexia

Assessment

! Cognitive Neuropsychological Assessment

• Structured according to existing models of normal reading

• to determine which subprocesses are intact and which are not

Assessment

! Core assessment Tools

• PALPA - Psycholinguistic assessment of language processing in aphasia

Kay, Lesser & Coltheart (1992).

• Word/Nonword list Coltheart & Leahy (1996)

• Graded Nonword Reading TestSnowling, Stothard, & McLean (1996).

SUBLEXICAL

LEXICAL

Speech

Assessment

• Sublexical Reading

• intact if nonword reading is age appropriate• Word/Nonword list (Coltheart & Leahy, 1996)

• Graded Nonword Reading Test (Snowling, Stothard, & McLean, 1996)

Assessment

• Lexical Reading

• intact if irregular word reading is age appropriate• Word/Nonword list (Coltheart & Leahy, 1996)

Assessment

• But, if impaired:• why is the child having difficulties with the lexical

and/or sublexical processing routes?• How do we treat the problem?

• Each process relies on the intact functioning of a number of subprocesses each of which may be dysfunctional

• We now need to assess each subcomponent of Lexical and Sublexical Route

SUBLEXICAL

LEXICAL

Speech

Assessment

! Intact if:• child can complete a cross case

matching task normally (PALPA Test 19 and 20)

Abstract LetterIdentification

SUBLEXICAL

LEXICAL

Speech

Assessment

Print! Intact if :

• irregular word reading aloud is normal (Coltheart and Leahy, 1996)

• child can complete a lexical decision task normally (PALPA Test 27)

Assessment

! Lexical Decision: child must decide whether a string of letters is a word

! stimuli• regular words (like, fresh)• exception words (have, both)• pseudohomophones (brume, gane)• nonwords (mide, noast)

Assessment

! child with a lexical deficit will rely on phonological decoding (‘sounding-out’)

• correctly accept regular words (e.g., like)• incorrectly reject exception words (e.g., both)• incorrectly accept pseudohomophones (e.g., brume)• correctly reject other nonwords (e.g., mide)

SUBLEXICAL

LEXICAL

Speech

Assessment

! Intact if:• child demonstrates normal

knowledge of word meanings through another modality (other than reading)

• ie. child can name pictures normally (PALPA Test 53)

• child can match spoken words to pictures (spoken word picture matching, PALPA Test 47)

Orthographic Input Lexicon

Semantic System

SUBLEXICAL

LEXICAL

Speech

Assessment

Print Abstract LetterIdentification ! Intact if:

• picture naming is normal (PALPA Test 53)

• spontaneous speech is normal

• child can provide a name when given a spoken definition

• e.g.. “What animal is large, grey and has large floppy ears and a long trunk?”

Semantics

Speech

SUBLEXICAL

LEXICAL

Speech

Spoken Word Retrieval

Speech

Semantics

Letter-Sound Associations

Breaking the word into ‘letter-chunks’

SoundBlending

• Break up the word into appropriate ‘chunks’ (eg. chooth or thick)

• Assign a sound to each ‘chunk’ - associate a letter/grapheme with its corresponding sound

• Blend the sounds together -convert a string of sounds into a single unified spoken form

Letter(s)-Sound Associations

Sound Blending

Assessment

! Intact if:• Child can break down a

word into appropriate chunks

• chick → ch i ck

Berndt & Mitchum (1994)Brunsdon et al (2002)

Sound Blending

Assessment

! Intact if:• Child has age

appropriate knowledge of letter to sound rules

• Letter sounding and spoken letter-written letter matching (PALPA test 22)

Sound Blending

Assessment

! Intact if:• Blend sounds together to

make a single unified pronunciation

• ie. if given the correct phonemes (sounds) the child can blend them together to make the target word or nonword

Breaking word into ‘letter-chunks’

Sound Blending

Treatment

Cognitive Neuropsychological Rehabilitation

• Always follows a systematic and theoretically driven assessment of the cognitive disorder

• Focus on direct remediation rather than compensatory strategies• Conducted at an individual level• Tailored to an individual’s specific pattern of impairment • Carefully designed to evaluate treatment efficacy

Treatment

CASE STUDIES:

! Sublexical Treatment! Lexical Treatment! Letter Processing Treatment

CASE DT

Brunsdon, R. K., Hannan T. J., Nickels, L., & Coltheart, M. (2002). Successful treatment of sublexical reading deficits in a child with dyslexia of the mixed type. Neuropsychological Rehabilitation, 12(3), 199-229

Case Description

• 9 year old boy • Year 5, mainstream primary school

Case Description

! Neuropsychological Assessment Results

• Severe deficits in• Language processing• Verbal new learning and memory• Sustained and divided attention• Problem solving• Reading, spelling and numeracy

Treatment Study

• Pretreatment Assessment

• lexical processing• sublexical processing• semantics• naming

Pre-treatment Assessment

• General Reading

10% (3/30) z <-2.41 17% (5/30) z <-2.41 3% (1/30) ) z <-2.27

Word/Nonword Test

IrregularRegularNonwords

Graded Nonword Reading Test

Speech

Semantics

SoundBlending

Sublexical Processing

20% Sound blending (aural)

56% 12%

Letter(s)-Phoneme KnowledgeLetter SoundingGrapheme sounding (e.g., ‘ch’)

30% Breaking words into chunks

Speech

Semantics

SoundBlending

Lexical Processing

10% (3/30) z <-2.41

Word/Nonword Test

Irregular

Speech

Semantics

Breaking word into ‘letter-chunks’

SoundBlending

Lexical Processing

poorpoormany identified as words

Visual Lexical decision

Regular wordsException wordsPseudo homophones

Semantics and Naming

88% Spoken picture naming95% Spoken word-picture matching

Speech

Letter-Sound AssociationsSemantics

SoundBlending

Pre-treatment Assessment

! Reading• Mixed dyslexia • Total inability to read non-words

• impairment in sub-lexical reading route• Poor sight word vocabulary

• underdeveloped lexical reading route• Comorbid cognitive difficulties

Treatment

! Aims:

• To improve the operation of the sublexical reading route

• To improve DT’s ability to ‘sound-out’ new words.

Treatment Study

! Aim• To improve the functioning of all three

sub-components of the sublexical reading route

Treatment Study

! Two treatment phases (over 4 months)

1. Letter to sound associations

2. ‘Letter-chunking’ and sound blending

Treatment - Phase 1

1. Grapheme to phoneme associations• Target stimuli

• 14 single letters• 27 graphemes (e.g., ch, sh)

• Duration • 8 weeks

Place this sheet in front of the child. Say “We are going to work on the sound ‘d’ (point to the D/d at the top of the page). “Repeat after me” (sound ‘d’ 3 times allowing the child to repeat each time). Say“Each of these words have the sound ‘d’ in them. Listen carefully and repeat after me”. (For each line sound the letter “d” and then read the word - point to the letter ‘d’ and then the word as you read them. Repeat each line 3 times).

d dogd dod dayd goodd downd underd dadd digd madd and

Treatment - Phase 2

2. Letter chunking and sound blending

• Stimuli• 2 nonword lists

• Duration • 8 weeks

Treatment Study

2. ‘Letter-chunking’ and sound blending• Method

• DT was required to:

1. Circle each letter-group2. Sound out each letter-group serially 3 times3. Combine the sounds

Treatment Study

Did treatment work?

Two baseline assessments prior to treatment:

• Letter sounding• Grapheme sounding e.g., ‘ch’, ‘th’• Nonword Reading

Baselines

3%0%Nonword Reading

17%8%Grapheme – sounding(e.g., ch oo th)

58%54%Letter sounding

Baseline 2Base1ine 1

ResultsPhase 2Phase 1

68%74% *18%3%0%Nonword Reading

92%92%88% *17%8%Grapheme –sounding (eg. ‘ch’)

92%92%92% *58%54%Letter sounding

3 months post-treatment

Post-treatment

Mid-treatment

Results

• Results

• Significant Improvement in:

• Sublexical reading skills (i.e., ‘sounding-out’ skills)

Results

• Generalisation to:

• word reading • general phonology

• Treatment effects enduring

CASE TJ

Brunsdon, R. K., Hannan T. J., Coltheart, M. & Nickels, L (2002). Treatment of Lexical Processing in Mixed Dyslexia: A Case Study.Neuropsychological Rehabilitation, 12(5), 385-418

Case Description

! TJ• 10 year old boy • Year 5, mainstream primary school• Poor academic achievement• Delays in receptive and expressive language

development

Case Description

! Neuropsychological Assessment Results• General cognition - low average range• Poor problem solving • Extremely limited reading and spelling

skills

Assessment

! Assessment:• Total inability to read non-words

• impairment of non-lexical reading route• Extremely limited sight word vocabulary

• underdeveloped lexical reading route

Breaking the word into ‘letter-chunks’Visual Word

RecognitionLetter-Sound Associations

Speech

Semantics

SoundBlending

Treatment

! Aims: • To improve the operation of the visual word

recognition system • To increase TJ’s sight word vocabulary

• 100 words targeted for treatment• 14 or 15 words per week

Treatment Study

• Treat list 1• test lists 1, 2, 3, 4, 5, 6 etc

• Treat list 2• retest lists 1-6 etc

• Treat list 3• retest lists 1- 6 etc

• etc

Treatment Study

• Stimuli• Flash cards containing target words• No picture cues

• Treatment • Weekly training and testing sessions (≈30 minutes)• daily home practice (≈5 mins)

Results

• Significant overall treatment effect

0102030405060708090

B1 B2 1 2 3 4 5 6 7po

Results

• Significant generalisation to untreated words

1 2 3 4 5 6Weeks

Results

• Significant improvement in spelling

% correct

pre post 1 post 2

Results

• Results

• Overall treatment efficacy• Generalisation of treatment effects to untreated words• Maintenance of treatment effects over time• Generalisation to spelling

• Cognitive neuropsychological theories and rehabilitation methods can be useful for children with severe mixed dyslexia.

• it is never to late to implement treatment even in children with virtually no functional reading skills

• Significant treatment gains despite severe comorbid phonological, language and cognitive impairment.

Discussion Point

• Traditionally used mnemonic cue may not increase efficacy of training for all children in early orthographic development

• ?May even be detrimental to efficient acquisition of orthographic representations

Samuels, 1967 Stuart, Masterson & Dixon, 2000

CASE ET

Brunsdon, R. K., Coltheart, M. & Nickels, L (In press). Severe Developmental Letter Processing Impairment: A Treatment Case Study. Cognitive Neuropsychology

Case Description

• 7 year old boy • Year 2, mainstream primary school

Case Description

! Neuropsychological Assessment Results

• Severe deficits in• IQ low average• History of language delay• Severe impairments in attention• Stimulant Medication since age 5

Case Description

! No reading or spelling abilities! Unable to name or sound letters! Very little improvement during Kindy

and Year 1

Assessment

! Assessment:

lower case upper case

• Letter Naming 6/26 7/26• Letter Sounding 5/26 0/26

Assessment

! Assessment revealed specific core deficits:

• Matching across case impossible• General letter knowledge impoverished

Treatment

! Aims: • To improve ET’s ability to:

• Sound letters

Treatment

Focus on core impairments:

• Poor abstract letter identification

• Poor semantic representation of letters

• Training in association of upper and lower case with a single sound

• Extensive semantic elaboration

Treatment Study

• Treatment

• Daily training (≈15 minutes) at home by mother• 26 letters

• 3 letters per week

Treatment

We used materials from Letterland (Manson & Wendon, 1997)

• Letterland flash cards• Letterland ABC Book

• contains a short story about each character • Letterland CD

• has a short song linking each letter character to their sound, set to a common nursery rhyme tune

Treatment

! Each day ET and his mother focussed on one letter

! They

• read the letter character story• looked at the lower case flash card and sounded the letter• sang the song• generated words beginning with the letter sound• looked at the upper case flash card and sounded the letter• Revision

Results%

Letter Sounding

Resultsor

Results

! Also improvements in:

! Reading words! Writing letters to dictation

What we have covered

! Assessment of reading• Identifying the underlying impairment

! Treatment of Reading Disorders• ‘Whole word’ processing• ‘Sounding out’ skills• Letter Processing

! Monitoring Treatment Efficacy

References

Berndt, R., & Mitchum, C. (1994). Approaches to the rehabilitation of "phonological assembly": Elaborating the model of nonlexical reading. In G.W. Humphreys & M.J. Riddoch, (Eds) Cognitive Neuropsychology and Cognitive Rehabilitation. London: Lawrence Erlbaum.

Castles, A., & Coltheart, M. (1993). Varieties of developmental dyslexia. Cognition, 47, 149-180.

Castles, A., & Coltheart, M. (1996). Cognitive correlates of developmental surface dyslexia: A single case study. Cognitive Neuropsychology, 13, 25-50.

*Coltheart, M., & Leahy, J.(1996).Assessment of lexical and nonlexical reading abilities in children: Some normative data. Australian Journal of Psychology, 48, 136-140.

*Edwards, V., & Hogben, J. (1999). New norms for comparing children's lexical and nonlexical reading: A further look at subtyping dyslexia. Australian Journal of Psychology, 5, 37-49.

Gathercole, S., & Baddeley, A.(1996). The Children's Test of Nonword Repetition. London: The Psychological Corporation Ltd.

Kay, J., Lesser, R., & Coltheart, M. (1992). Psycholinguistic assessments of language processing in aphasia (PALPA). Sussex, UK: Lawrence Erlbaum Ltd.

Manson, J., & Wendon, L. (1997). Letterland Early Years Handbook. Letter Land International: Cambridge. (http://www.letterland.com)

Samuels, S.J. (1967). Attentional processes in reading: The effect of pictures on the acquisition of reading responses. Journal of Educational Psychology, 57, 337-40

Snowling, M., Stothard, S., & McLean, J. (1996). Graded Nonword Reading Test. Suffolk, England: Thames Valley Test Company

Stuart, M., Masterson, J., & Dixon, M (2000). Spongelike acquisition of sight vocabulary in beginning readers? Journal of Research in Reading, 23, 12-27.

*Norms for Word/Nonword Test

Assessment and Treatment of Reading Disorders: A … Brunsdon.pdf · Reading Disorders: A Cognitive...

Documents