Late talkers and specific language impairment

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When should we be concerned about late-talking toddlers? A slideshow by Professor Dorothy Bishop of Oxford University for the RALLI campaign.
see http://www.youtube.com/rallicampaign

Published in: Health & Medicine, Technology

Late talkers and specific language impairment

  1. 1. When should we be concerned about late-talking toddlers? Dorothy V. M. Bishop 1
  2. 2. Wide variation in age at first words Language milestones 100 90 80 70 Boys, sentences Percentile% children 60with words Girls sentencesor sentences 50 Boys, single wordsat given age 40 30 Girls, single words 20 10 Single words-”Three or four 0 different words for people or objects, correctly used.” 0 12 24 36 Sentences-”Three or more words, strung together to Age in months make some sort of sense.” Epidemiological sample of children born in Newcastle-upon-Tyne Neligan, G. A., & Prudham, D. (1969). Norms for four standard developmental milestones by sex, social class and place in family. Developmental Medicine and Child Neurology, 11, 413-422. 2
  3. 3. Most children with long-term language problems were late talkers Language milestones 100 90 80 70Percentile 60 Boys, single words 50 Girls, single words 40 SLI 30 20 10 0 0 12 24 36 48 60 Age in monthsRed shows Neligan/Prudham normsBlue shows children from Dawn House School- NB severe SLI 3Only 12% of SLI had first words before 18 months
  4. 4. http://www.johnbercow.co.uk/ 23012007_disabled_children• I believe that we suffer continually in this country from a problem of late assessment, late identification and late diagnosis. ….• I believe that sometimes those operating the system play precisely upon the hopes, as well as the more exaggerated fears, of some parents by saying, “Don’t worry. There’s plenty of time.” Of course, those who are articulating that message very often have a reason of financial self-interest for holding back the provision of what is needed. 4
  5. 5. Most children who have SLI were late talkers, ≠ most late talkers will have SLI Key issue of ‘base rates’ Consider population of 1000 children • In whole population, 10% are late talkers = 100 cases • Suppose 3% of children have severe SLI In population of 1000, will be 30 cases of severe SLI 88% of severe SLI were late talkers (i.e. first words after 18 months), = 26 cases • So only 26/100 late talkers will have severe SLI 5
  6. 6. Butphenomenon ofdo ‘grow out of it’:The many children the ‘late bloomer’ Late bloomers Fischel et al (1989) •26 2-year-olds who “understood complete sentences but who could say only a few words.” •Followed after 5 months Approx 1/3 no improvement 1/3 mild improvement 1/3 in the normal rangeFischel, J. E., Whitehurst, G. J., Caulfield, M. B., & Debaryshe, B. (1989). Languagegrowth in children with expressive language delay. Pediatrics, 83, 218-227. 6
  7. 7. General agreement: early intervention better than late• Failure to intervene may lead to development of secondary problems• Also, notion of brain plasticity• Easier to modify brain development before neural pathways are committed 7
  8. 8. Brain plasticity example: eye-patching (occlusion) for ‘lazy eye’ Effectiveness of occlusion by age 100 % change eye acuity In vision, 80 much better difference 60 outcome of treatment if 40 done early in life 20 0 24 36 48 60 72 84 96 108 120 132 144 Age (months)Epelbaum, M. et al (1993). The sensitive period for strabismic amblyopia in humans. 8Ophthalmology, 100(3), 323-327.
  9. 9. Is there a “sensitive period” for language Evidence from ‘natural experiments’, e.g. ultimate skill of second language learners much better for those who came to new country before 10 yr old Adults tested on grammaticality judgement task, e.g. judge correct/incorrect: The man allows his son to watch TV The man allows his son watch TV The man lets his son to watch TV The man lets his son watch TV Grammar test score 280 260 240 220 200 native 3 to 7 8 to 10 11 to 15 17 to 39 Age at arriving in USJohnson, J. S., & Newport, E. L. (1989). Critical period effects in second language learning: the influence ofmaturational state on the acquisition of English as a second language. Cognitive Psychology, 21, 60-99 9 .
  10. 10. The quandary• Late intervention – Children develop secondary problems – May be too late to be effective• Early intervention: – Risk of intervening with children who are just ‘late bloomers’ – wasted resources – May create problems in the child 10
  11. 11. What is needed• Some way of distinguishing ‘late bloomers’ from those with more persistent problems 11
  12. 12. How to find out?• Need studies that start with late talkers and follow them up• At follow-up, divide into those who have resolved and those with persistent problems• Then look at time 1 data and see if we could have distinguished them 12
  13. 13. What factors likely to affect outcome?• Home environment*• Birth risk*• Genetic risk*• Severity of language delay• Profile of language difficulties* Predictors of late talking in study by Zubrick, S. R., et al (2007). Late language emergence at24 months: An epidemiological study of prevalence, predictors, and covariates. Journal ofSpeech, Language and Hearing Research, 50(6), 1562-1592. doi: 1310.1044/1092-4388(2007/106)
  14. 14. Our study: the children • Recruited from a database of families from local maternity ward and local toddler groups. • Mothers filled in Oxford University Communicative Development Inventory (OCDI) when child 18-19 mo old: long list of words – parent indicates if child says word and understands it, or just understands, or neitherBishop, D. V. M., Holt, G., Line, E., McDonald, D., McDonald, S., & Watt, H. (2012).Parental phonological memory contributes to prediction of outcome of late talkers from 20months to 4 years: a longitudinal study of precursors of specific language impairment.Journal of Neurodevelopmental Disorders, 4(3). doi: 10.1186/1866-1955-4-3 14
  15. 15. Section of OCDI understandsunderstandsand saysTotal OCDI has 416 words; At 18 months, bottom 15% say <= 10 words 15
  16. 16. The children• 26 late talkers: expressive OCDI more than 1 SD below the mean (<= 10 words)• 70 average talkers: OCDI from 20th to 75th centile• Aimed to include children with a family history of speech/language problems – defined as having 1st degree relative with history of receiving intervention for language or reading problems• Child seen for a language and cognitive assessment• 24 late talkers and 59 average talkers available for follow-up at 4 yr. 16
  17. 17. Assessment at 20 months• Vineland Adaptive Behavior Scales, 2nd edition (VABS) – Parental interview used to evaluate the childs development in the areas of Communication, Socialisation, Daily Living, and Motor Skills.• Mullen Scales of Early Learning – Child-based assessment that provides scores for Gross Motor, Visual Reception, Fine Motor, Expressive Language, and Receptive Language skills. 17
  18. 18. Assessment at 20 months• Mullen Scales of Early Learning – Child-based assessment that provides scores for Gross Motor, Visual Reception, Fine Motor, Expressive Language, and Receptive Language skills. 18
  19. 19. Assessment at 4 years• Nonverbal Ability• Expressive and receptive language• Parental report of communication skillsAlso brief assessment of parental language (done when child 20 months and 4 years – just one parent, usually the mother) 19
  20. 20. Classification at 4 yrs N• Typical development (TD): Normal range nonverbal ability and no more than one impaired language measure 60• Specific language impairment (SLI): impaired on at least two language measures, with normal 15 nonverbal ability• In addition, 7 children with below average nonverbal ability – not considered further 20
  21. 21. Predicting outcome for individual childrenBest prediction of 4 yr outcome from:• Child’s language at 20 months + family history + parent nonword repetition; Prediction was better than chance, but far from perfect 21
  22. 22. Clinical prediction for individual childrenSimple rules of thumb from our data:High risk of persistent language problems if: + Family history and mother scores more than 1 SD below average on nonword repetition test.OR No family history but Vineland communication is below 85 (1 SD below mean) 22
  23. 23. Other factors to considerThal et al (1991)• Poor outcome specifically in those with poor comprehension/gestureOur study• Comprehension measures did not add much to prediction but our sample had few children with poor comprehension at 18 months• Have not yet analysed measures of gestureThal, D. J., Tobias, S., & Morrison, D. (1991). Language and gesture in late talkers: aone-year follow-up. Journal of Speech and Hearing Research, 34, 604-612. 23
  24. 24. Summary• Majority of late talkers did not have later language difficulties• Having a family history of language/literacy problems is a risk factor for persisting problems• Poor comprehension or lack of gesture may also be important predictors• Parental report on Vineland can also help identify those likely to need help• Appropriate to adopt ‘watchful waiting’ strategy with late talkers who have good comprehension and don’t have family history of language problems 24

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