Early Identification and Intervention for Children with

Reading Difficulties

Deborah KnightCHERI Conference September, 2005

The Case for Early Intervention! Chronicity – probability that a Year 1 reader will

remain a poor reader in Year 4 = .88 (Juel, 1988)

! Increasingly restricted access to the curriculum- ramifications for broader knowledge base and

associated cognitive skills

! Elevated risk for development of emotional andbehavioural difficulties

Prediction- Historical OverviewEfforts to identify predictive variables driven by available, often

disparate theoretical ideas.

Broad based perceptual difficulties:Smith (1928) – ability to match letters in early Year 1 predicted

word reading skills in late Year 1Monroe (1935) – pre-reading battery included measures of

oculomotor control, attention, motor skills,auditory discrimination, vocabulary

Visual perceptual difficulties:Bond & Dykstra (1967) – familiarity with print, auditory – visual

discriminationFrostig battery – visual closure, figure – ground discrimination

Early neuropsychological models: Satz et al (1978): visual perceptual skills, vocabulary, alphabet

recitation, SESSilver & Hagin (1975): auditory & visual discrimination, finger

agnosia, praxis, right-left discrimination

Ill defined constructs, batteries proved to have limited predictive validity.

Phonological Processing Deficits

Reading and spelling difficulties exist on the continuum of developmental language disorders.

Primary difficulty arises from weaknesses in encoding and processing the phonological or speech sounds of the child’s language. Compromises child’s ability to efficiently convert letters or groups of letters into the speech codes they represent.

Phonological Processing Deficits

Affected children experience difficulties forming and maintaining clear representations of speech sounds. Phonological codes (cognitive structures that aid in the perception and production of speech sounds) - “fuzzy”, indistinct or unstable.

Sluggish and inaccurate processing of speech sounds

difficulties in developing an awareness of the sound structure of words and in establishing reliable and easily accessible links between written and spoken language ie “cracking the alphabetic code”.

Lexical Restructuring Hypothesis(Metsala & Walley,1998)

Input Output

Phonological Representations

Rapid growth in vocabulary increasing pressure during early childhood for sound structure of words to be represented in waysthat make words readily distinguishable.

whole word - shallow levels – normally develops duringsyllable preschool years via natural languageonset – rime experiences

phoneme - deeper levels - develops through exposure to text and instruction

Poorly specified phonological codes

Poor phonological awareness: capacity to reflect on and manipulate (segment & blend) sounds within words

Slow naming speed & laboured retrieval of sounds: Phonological codes activated too slowly to permitefficient encoding of letter combinations found in words. Constrains reading fluency due to slower individual word recognition.

Verbal working memory deficits: Laboured access to speech codes → poor blending skills and difficulties assembling sound units in words.

Difficulties in speech perception and production

Early Identification Studies

Unselected samples“ At risk” samples:

Children with speech and language difficulties-at a 4 to 5 fold risk of developing reading difficulties vsunaffected children

Children with a family history of reading difficulties – around a 40-50% risk for the child

Model: administer measures prior to start of formal instruction and track reading progress over time.

Skills that underpin normal reading development are also the best predictors of impaired development.

Phonological Awareness: assumes predictive power in late preschool period; continuity found in development from shallow (word, syllable, onset-rime segmentation) to phonemic sensitivity. Tasks: rhyme oddity detection (boat, snail, nail)

alliteration oddity detection (car, cat, sun)blending syllables & phonemeselision (say a word then delete syllable or

phoneme)

Letter Name Knowledge – in late preschool/early K a potent predictor of reading competence in Year 1. Assists learning of letter sounds and associated development of phonemic sensitivity.

Naming speed – RAN digits. Provides an index of the child’s capacity to quickly retrieve sound based material from memory.

Oral language skills – vocabulary level, syntacticand narrative skills.

RAN tasko a s d p a o s p d

s d a p d o a p s o

a o s p s d p o d a

d a p o d s a s o p

o a d s d p o a p s

Does prediction change over time?

Late preschool: oral language measures exert a sizeable effect (around 25-40% variance) on later

(Y1) reading competence.

: letter name knowledge

: phonological awareness

combined provide substantial predictive relevance(approx. 50% variance in K & Year 1 decoding skills)

Kindergarten: 3 skill areas consistently shown to have strong predictive relevance for Year 1 and Year 2 word recognition and reading comprehension skills.

! Phonological awareness ! Letter name knowledge (early K)

Letter sound knowledge (late K)! Letter naming speed

Together explain between 40 –60% variance in Year 1 reading. Predictive power diminishes over time - 30% in Year 2.

No significant contribution found for IQ, non-verbal skills or print concept knowledge.

Oral language (vocabulary and syntactic) skills re-emerge as again predictive around Year 3 with increased demands on more complex text comprehension.

Current measures administered in Kindergarten tend to yield high rate of false positives . Difficulties offset by early introduction of code-based instruction and regular monitoring of the children’s progress throughout the course of instruction.

Prediction for “at risk” childrenChildren with speech and language difficulties at inflated risk of literacy problems. Evident for both receptive and expressive domains. Reduced vocabulary early on impedes development of finer representational codes and later understanding of more complex text; expressive difficulties compromise formation of stable and distinct phonological codes and ease of access to these codes.

Identified markers for speech and language impaired children in K similar to those in randomly selected samples.- letter identification, phonological awareness, rapid naming, sentence imitation.

Probability equation including above variables plus maternal education level yielded 93.3% hit rate in identifying Y2 reading difficulties from K administered measures (Catts et al, 2001).

Children at genetic riskScarborough (1990)

32 2 year olds, family history of RD vs control childrenAt age 8 years - 65% (20 children) exhibited RD

at 30 months - more speech production errors- poorer syntax

at 36 & 42 months - less well developed vocabulary - persistent syntactic difficulties

at 5 years - poorer letter knowledge- poorly developed phonological

awareness- expressive naming difficulties

Preschool (2-4 years)- poor speech production - weak vocabulary - syntactic weaknesses

Late Preschool – Early Schooling (4-6 years)- letter name knowledge- phonological awareness- naming speed- speech perception & production- vocabulary

Family risk continuity(Byrne et al, 1997; Locke et al, 1997; Elbro et al, 1998; Gallagher et al, 2000;

Pennington & Lefly, 2001; Lyytinen et al, 2001; Molfese et al, 2001; Snowling et al, 2003)

At risk markers:Family history of reading difficultiesDelayed speech and language development – slow vocabulary development, poor expressive language, weak syntaxPersistent problems with sound processing, inconsistent speech productionProblems mastering production of new wordsPoor phonological sensitivityEvident naming, word retrieval difficultiesDifficulty learning the alphabetPoor invented spelling

Early ID Measures - articulation accuracy- phoneme identification & deletion - naming speed tasks- repetition of non-words- letter name /letter sound knowledge

Available tests: DIBELS http://dibels.uoregon.edu/CTOPP (Pro-Ed)PhAB (ACER)SPAT -R

InterventionLundberg’s work (1988)- phonological awareness training for K children, oral basedBryant & Bradley (1985) – training in pa integrated with letter-sound correspondences; sound categorisation skillsByrne et al (1989, 1990) – Preschool children. Taughtarticulatory cues for production of sounds; phoneme identity training, letter-sound mappings.Ball & Blachman (1991) – “Say It & Move It”, letter-sound training together with explicit training in segmentation strategies

Programs vary in level of phonological sensitivity addressed, whether phoneme-grapheme connections are taught, degree to which decoding strategies are included.

Evidence for young children (preschool, early K) –training of phonological awareness can significantly enhance children’s phonemic sensitivity (av. effect size .86); longer term effects on word reading ability (decoding skills) evident through primary schooling. (Byrne & Fielding-Barnsley,2000; Elbro & Petersen, 2004)

Indicators: training at phoneme level more effective vs rhyme identity & production

:better outcomes when letter-sound mappings are trained

: inclusion of articulatory cueing probably beneficial

: group instruction for young children as effective as individual training

Not a guaranteed innoculation effect, particularly for ‘at risk’ children. Proportion of children who show limited or no improvement in pa.

Identified predictors - pretraining pronunciation quality and phoneme discrimination.

School-aged samples:Substantial evidence supporting efficacy of explicit

training in letter – sound knowledge, phonological awareness and phonemic decoding strategies for promoting reading development. (Vellutino et al, 1996; Foorman et al, 1998; Torgesen, 1999, 2000).

Direct code instruction (teaches letter-sound correspondences, phonemic awareness, blending skills, provides practice with phonetically controlled text, writing) produces stronger reading growth for children with phonological weaknesses vs indirect, text level instruction

Instruction should commence early to minimise effects on fluency of reduced successful exposure to text.

Improved decoding skills promote development of text comprehension

Outcomes support efficacy of a range of instructional contexts: whole class, small group, individualised

What about the “treatment resisters”? Typically between 2-6% of children.

Remediation vs PreventionRemediation Prevention

Y3 –Y6 (67.5 hours) mid K –Y2 (88 hours)

Pre 2yr FU Y2 Y4

Text Rate 71.3 71.7 93.3 96.8Text Accuracy 75.8 91.0 96.7 98.5Word Attack 69.3 91.9 101.1 99.8Word Ident. 67.6 85.5 100.7 95.6