Literacy and dyslexia in oral deaf children

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Literacy and dyslexia in oral deaf children Ros Herman, Penny Roy & Fiona Kyle City University London

Conference presentation for the British Dyslexia Association, 2014

Reading in deaf and hearing children •Deaf children often experience difficulties with learning to read1 •Hearing children with reading difficulties are likely to be diagnosed as dyslexic, whereas deaf children’s difficulties are attributed solely to their sensory loss •Given the genetic basis of dyslexia2, might some deaf children also be dyslexic? 1Allen,

1986; Conrad, 1979; Kyle & Harris, 2010; 2011; Wauters, van Bon & Tellings, 2006; 2Pennington & Olson, 2005

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Diagnosing dyslexia • Reading develops in the same way in deaf and hearing children: phonological skills are key • Dyslexia typically presents as a problem with decoding written words based on poor phonological skills • BUT there is no UK normative data for deaf children so differentiating poor reading due to deafness vs dyslexia is difficult 3

Phase 1: Oral deaf children Aims: Phase 2: Signing deaf children 1. Investigate the suitability of literacy and dyslexiasensitive tests for deaf children 2. Collect data from a representative sample of oral deaf children 3. Compare deaf readers to hearing children with and without dyslexia 4. Identify key predictors of literacy skills in deaf children in comparison with hearing dyslexic children 5. Find out if some deaf children have dyslexia

Participants in Phase 1 • 79 severely-profoundly children deaf from birth • Year 6 (10-11years), primary education in English

• 61% cochlear implants, 39% digital hearing aids: no difference in reading and phonological skills so combined into one group • Reference group of 20 hearing dyslexic children

Test battery  Literacy – Single words, nonword reading, reading comprehension, spelling

 Phonological tasks

   

– – – – –

Digit span Fluency: rhyme, alliteration Phoneme deletion (rein/deer) Spoonerism (fun with “b”; riding boot) Naming speed

Non verbal IQ Expressive vocabulary Speechreading and speech intelligibility Familiar sequences 6

Deaf-friendly test administration: listening conditions • Quiet and distraction free test environment, important for hearing aid/cochlear implant users • Amplification fully functional prior to assessment

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Deaf-friendly test administration: visual access • Optimal seating and lighting • Access to clear speech patterns to support lip reading

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Tester skills • Signing/gesture/writing used as needed to explain tasks • Additional practice items offered where needed • Sensitivity to deaf children’s speech patterns in scoring Note: all tests administered using spoken language only 9

Comparing deaf participants with hearing test norms • Deaf children had poor scores on most of the phonological tasks, especially phoneme deletion • Deaf children particularly poor on vocabulary • Deaf children showed a normal spread of scores on naming speed for digits, NVIQ, speech reading, semantic fluency 10

Comparing deaf and hearing dyslexic children: Single word reading Hearing dyslexic children

Deaf children

30% 48% 52%

Average readers

Average readers 70% Poor readers

Poor readers

Comparing deaf and hearing dyslexic children: Single word reading Hearing dyslexic children

Deaf children 6%

Average readers 30%

Poor readers

42%

Average readers

52% Extremely poor readers

70%

Poor readers

Other literacy scores Reading comprehension: • 39% deaf in normal range Spelling: • 60% deaf in normal range

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Evaluating our measures: Predictors of literacy skills in deaf children

Word reading

• Vocabulary • Phoneme deletion

Nonword reading

• Phoneme deletion • Spoonerisms

Spelling

• Vocabulary • Naming speed for digits

Can we identify dyslexia in oral deaf children?

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Classification of reading skills Good language skills Deaf 0%

Poor decoding skills

Deaf 48%

Deaf 30% Dyslexic readers (PR)

Poor readers, poor language (PR + PL)

Average readers

Average readers, poor language (PL)

Good decoding skills (Nonword reading) Deaf 22%

Poor language skills (Expressive vocabulary) Based on Bishop & Snowling 2004

Why do deaf children have reading problems? The role of early language experience Limited early language experience

Poor speech perception and production

Poor vocabulary development

Poor phonological representations and awareness

Poor reading Inefficient word learning

So were any deaf readers dyslexic?

Poor readers Average readers

6% ‘extremely poor’ deaf readers: • severe phonological deficits • lowest scores across all measures We cannot tell if they have dyslexia Their response to intervention may be informative

Naming speed a key measure in identifying dyslexia Eight children with average speech intelligibility and nonverbal scores BUT low scores on naming speed Three with average non-word reading unlikely to be dyslexic

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Naming speed a key measure in identifying dyslexia Of the five remaining, all were: – Very poor spellers (phonetic spelling errors) – Very poor phonological skills (spoonerisms, phoneme deletion) – Very poor sequencing skills (months in correct sequence) – 4/5 were boys

These children fit the typical dyslexic profile

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Phase 1: Conclusions  Some oral deaf children do have a dyslexic profile BUT these are not the only poor readers  Half our oral deaf sample are poor readers, all with poor language and weak phonological skills  Using more recent norms for BAS single word reading test, 71% are poor readers  Deaf children’s phonological deficits are the same as those found in hearing children with dyslexia

What happens next?  These children are poorly equipped for secondary school  All poor deaf readers need support not just the few that may have dyslexic profiles Interventions that work with hearing dyslexic children should be available to poor deaf readers Like hearing children with severe reading difficulties, deaf children need intensive, individualised, ongoing interventions to address both language and phonological deficits Ideally, intervention should be early to prevent these problems

Acknowledgements Thanks to…

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 My collaborators, Penny Roy & Fiona Kyle The Nuffield Foundation  All the children, families and schools who took part Our research assistants: Zoe Shergold for phase 1 and Catherine Barnett for phase 2  Advisory group: Sue Brownson, Margaret Harris, Mairead MacSweeney, Barbara Maughan, Ian Noon, Kate Rowley, Karen Simpson, Maggie Snowling, Ruth Swanwick & Tyron Woolfe 23