Treating reading disability without reading: evaluating alternative intervention approaches

1. Treating reading disability without reading: evaluating alternative intervention approaches Dorothy Bishop University of Oxford See Notes view (Edit menu, Edit slides) for text for this presentation

2. Conventional approaches to dyslexia • Most children have problems with “phonological awareness” • Interventions focus on training children to identify sounds in words and relate these to letters

3. Problems with conventional approach • Intensive and prolonged phonological intervention can be effective in improving reading accuracy • Reading fluency remains a problem • Methods that are effective for most children, don’t work for all: A hard core of children remain very hard to treat

4. Neuroscience studies of developmental disorders The Holy Grail Develop a theory of the disorder that not only explains why it occurs, but also motivates effective intervention

5. Goals of this talk • Identify some questions for parents considering a new treatments • Illustrate with Dore method and fish oil

6. How to measure reading – a brief digression

7. How to measure reading etc. A 9-year-old reads 20 words Reading Age is 8 years: Sounds bad: 12 months behind age level

8. Reading age misleading: does not take into account spread of scores at a given age; non-linear relation with chronological age A 9-year-old reads 20 words. Error bars show middle 50% of children Within normal range for children of this age

9. Better to measure reading in terms of statistical abnormality at that age Beware of studies that rely on “reading age”: Percentile: % of children of this age obtaining this score or lower; Also z-score or standard score: different way of expressing same idea

10. Some questions to ask of a new treatment • Is the theory scientifically plausible? • Does evidence for efficacy go beyond testimonials? – Have studies been done with groups for whom treatment is recommended? • Is there evidence that gains are due to treatment rather than maturation, practice, placebo, etc.? • Are costs reasonable relative to benefits?

11. Dore method: what is it? • Method for curing cerebellar problems developed by Wynford Dore to help his dyslexic daughter • Individualised program of exercises, done for around 10 mins, 2 x per day, assessed every 6 weeks

12. Dore method: the exercises • Hundreds of exercises, e.g.: • standing on a cushion on one leg and throwing a beanbag from one hand to another for one minute • hopping on one leg in large circle, clockwise then anticlockwise • sitting upright in a chair, turning head from side to side, pausing to focus on chosen point • balancing on a wobble board (Examples only: full details confidential because commercially sensitive)

13. Dore method: the theory • Dyslexia and other learning difficulties arise when the cerebellum fails to develop normally • Cerebellar impairments differ from person to person but can be diagnosed by specific tests of mental and physical co-ordination

14. Cerebellar theory of dyslexia • Not proven, but some evidence for it • Brain imaging and neuroanatomical studies offer some support • Theory that dyslexia involves failure to automatise skills is plausible • Associated deficits in motor co-ordination in a subset of people with dyslexia

15. Previous research on effectiveness of motor training • Training can improve performance on motor tasks, e.g. juggling • In rats, exercise can reverse cerebellar deficits caused by prenatal alcohol or zero gravity • But no evidence that motor training enhances development of non-motor skills

16. The Theory: evaluation • Notion that training motor skills will have effect on other skills: • “This hypothesis required something of a leap of faith, in that it is generally believed that the cerebellum comprises a very large number of independent ‘cerebro-cortical microzones’, and so it is not clear why training on one sort of task should generalize to unrelated tasks” (Reynolds et al, 2003, p 53)

17. Duncan Goodhew Kenny Logan Greg Louganis Paul Nixon The Theory: evaluation • If training focusing on one region of cerebellum had general effects on all cerebellar functions, then • activities like juggling and skateboarding should protect against dyslexia • sportsmen and women should have low risk of dyslexia

18. Questions 1. Is the theory scientifically plausible? • Notion that cerebellum may be implicated in dyslexia is plausible though not proven • Notion that motor exercises will have beneficial effect on regions of cerebellum concerned with learning is considerably less plausible

19. Does evidence for efficacy goes beyond testimonials? One published study on Dore intervention • Two papers in Dyslexia reporting different phases

20. Have studies been done with groups for whom treatment is recommended? • 2003 study: 296 children from 3 school yrs • Selected 35 “at risk” on basis of Dyslexia Screening Test : strong risk in 34%, mild in 21%, remainder fall below ‘at risk’ level • Divided randomly into untreated and treated groups • Previous diagnoses: • treated: 4 dyslexic, 1 dyspraxic • control: 2 dyslexic, 1 dyspraxic, 1 ADHD

21. Results as reported by Dore organisation • Dore (2006): results were “stunning” and: • reading age, increased 3 x • comprehension age: increased almost 5 x • writing, increased by “an extraordinary” 17 x

22. Data from school-administered tests, treated group only % improvement calculated by dividing orange line by pink line, i.e. change from time 2 to 3, divided by change from time 1 to 2 Conclude “reading age increased 3 times” But misleading: depends on low score at time 2 Why use ‘reading age’ when test has scaled scores?

23. Data from SATS (treated children only) “Designed for assessment of attainment rather than psychometric rigour” (Reynolds & Nicolson, 2007) • Level 2: average for typical 7 yr old • Level 3: average for typical 9 yr old • Level 4: average for typical 11 yr old “One should not over-interpret these data”(Reynolds & Nicolson, 2007)

24. Q3. Is there evidence that gains are due to treatment?

25. Uninteresting reasons why scores may improve - 1 • Maturation • Children change with age • Shoe size may go up after treatment, but does not mean that treatment made feet bigger • Not an issue if age-adjusted scores used but problematic if reliant on ‘reading age’ or tests with no age norms (e.g. balance tests)

26. Uninteresting reasons why scores may improve - 2 • Placebo effect / effect of other intervention • Child may be having other help or may respond to increased attention

27. Uninteresting reasons why scores may improve - 3 • Practice effects • Child does test better 2nd time around because they have done it before • Numerous examples in research literature: e.g. Dyslexia Screening Test manual recommends that ‘semantic fluency’ subtest is not valid if given twice because children tend to practice once they have done the test

28. Uninteresting reasons why scores may improve - 4 • Regression to the mean • Statistical artefact whereby someone selected for extreme score at time 1 will on average have less extreme score at time 2 “Regression to the mean is as inevitable as death and taxes” Campbell & Kenny (1999) A primer on regression artefacts

29. Regression to the mean Correlation between time 1 and time 2 = .06

30. Regression to the mean Correlation between time 1 and time 2 = .99

31. Regression to the mean Correlation between time 1 and time 2 = .76 “Social scientists incorrectly estimate the effects of ameliorative interventions.....and snake-oil peddlers earn a healthy living all because our intuition fails when trying to comprehend regression toward the mean” (Campbell & Kenny, 1999)

32. These unwanted sources of change can be identified if we have a CONTROL GROUP • Untreated matched group given same pre- and post-test will control for: • Maturation • Effects of other intervention • Practice effects • Regression to the mean

33. Alternative treatment control group • Crucial to see if improvement due to: • Placebo/expectation effects • Child, parent, teachers all expect and want to see gains • Child gets more attention, boosted confidence, etc.

34. Dore study did include untreated control group

35. Results: total on dyslexia screening • High score indicates more risk • NB score include bead-threading/posture • Treated: mean fell from 0.74 to 0.34 • “strong risk” fell from 33% to 11% • Control: mean fell from 0.72 to 0.44 • “strong risk” fell from 35% to 24% Everyone improves, even if not treated

36. Significant group differences in gain on bead threading, semantic fluency and reading

37. Control group subsequently given the treatment • Results published in Dyslexia journal in 2007 • Control group now known as group D (delayed intervention), and compared with original intervention group (I)

38. Results on dyslexia screening test, time 1 and time 4 N.B. No control data – both groups now treated Note: lack of “stunning” progress on literacy tests

39. Is there evidence of gains due to treatment? • Improvement looks best for measures where there is no control data • On reading measures where control group available, initial gain in the treated group on reading was small and not sustained

40. Costs in relation to benefits Cost of treatment is around £1700-£2000: “ Surely it is a price worth paying in the attempt to transform the life of your child so that they are able to enjoy school, to develop social skills, to develop good sporting skills, to have good prospects in life?” Dore (2006) p. 171 “Money-back guarantee” But only if “no physiological change” – i.e. child who improves on balance/eye tracking won’t get refund, even if dyslexia/ADHD etc unchanged

41. Fish oil

42. The theory • Certain highly unsaturated fatty acids (HUFAs) important in brain development and neuronal signal transduction • Brain function may be affected by: • Dietary insufficiency • Genetic abnormality in phospholipid metabolism • Administration of HUFAs may improve synaptic transmission

43. Evidence of abnormal fatty acid levels in dyslexia • Clinical signs of fatty acid deficiency* found in adults with dyslexia (Taylor et al, 2000) • Clinical signs of FAD correlate with severity of dyslexia in males only (Richardson et al, 2000) * 7 items including dry skin/hair/nails, excess thirst, frequent urination

44. Evidence from treatment trials • Significant reduction in ADHD symptoms in children with comorbid dyslexia/ADHD cf. placebo (Richardson & Puri, 2002) • reading not assessed (!!??) • Cf. no improvement of ADHD symptoms vs. placebo in 2 studies of ADHD, though studies vary in fatty acid, sample, etc • Hirayama et al. 2004 • Voigt et al. ,2001

45. Evidence from treatment trials • Oxford-Durham study on children with developmental coordination disorder; Treated show significantly more improvement in literacy (reading age!) and ADHD symptoms: (Richardson & Montgomery, 2005) • Requests to see raw data to identify children with dyslexia from this sample get no response

46. Controlled trial of fish oil in dyslexic adults • Cyhlarova et al, 2007 report baseline results - no differences in membrane fatty acid levels between dyslexic and control adults, though ratio of types of fatty acid differs • Requests for information on progress of this treatment trial get no response

47. Q1. Is the theory scientifically plausible? • Membrane phospholipid deficiency: speculative theory developed to account for schizophrenia, extended to neurodevelopmental disorders • Most plausible when applied to children who show physical symptoms suggestive of essential fatty acid deficiency

48. Q2. Does evidence for efficacy goes beyond testimonials? – have studies been done with groups for whom treatment is recommended? • Several clinical trials but only one specifically on children with dyslexia (and ADHD) - did not look at reading outcomes • Study of developmental coordination disorder included measures of reading as part of outcome assessment

49. Q3. Is there evidence that gains are due to treatment? • Inclusion of control group makes it possible to take into account practice, maturation, etc.

50. Q4. Are costs reasonable? • around £19.50 for 60 capsules (1 per day) • Treatment may need to be ‘long term’ • £118 per year