Return to Video

Dorothy Bishop: Evaluating Alternative Solutions for Dyslexia

  • 0:00 - 0:06
    [Dorothy Bishop] I'm going to talk today about evaluating alternative intervention approaches to dyslexia.
  • 0:06 - 0:07
    [slide with talk title]
  • 0:07 - 0:14
    The conventional approaches that you get really tend to rely on the fact that we've now got of evidence
  • 0:14 - 0:18
    that most children with dyslexia have problems in what is called phonological awareness,
  • 0:18 - 0:23
    that is, they don't necessarily hear all the different sounds in speech,
  • 0:23 - 0:28
    and therefore have difficulty relating them to letters when they are trying to read.
  • 0:28 - 0:38
    And most of the interventions that are mainstream these days would focus on trying to train children to identify sounds in words and relate them to letters.
  • 0:39 - 0:45
    But this sort of intervention has been shown to be effective, and there have been a number of large scale studies.
  • 0:45 - 0:52
    But nevertheless, it has to be fairly prolonged for some children, and there are children for whom,
  • 0:52 - 0:58
    even though they can learn this way to actually sound out words and read, they don't necessarily read fluently.
  • 0:58 - 1:03
    It's still an effort for them, and they don't sort of get to the degree of automaticity that you might expect,
  • 1:03 - 1:08
    And it's certainly the case that methods that work for many children don't work for all children,
  • 1:08 - 1:11
    and there is a hard core of children who remain very hard to treat.
  • 1:11 - 1:16
    It is for this reason that many parents do get very concerned about whether there is something else they should be doing
  • 1:16 - 1:22
    if they are finding that their child is either not getting intervention, or that the intervention doesn't seem to be working very well.
  • 1:22 - 1:29
    And there are a whole load of things out there that are on offer, and the problem for the parents, I think -
  • 1:29 - 1:34
    and/or indeed for adults who themselves, might want to have further intervention for dyslexia -
  • 1:34 - 1:38
    is that they want to know, "how do I distinguish something that might work for me",
  • 1:38 - 1:42
    from something that is just some sort of snake-oil merchant who is out there to make money.
  • 1:42 - 1:44
    And that's what I want to try and address today.
  • 1:44 - 1:52
    principally from the perspective of how you might evaluate scientific evidence that people put forward.
  • 1:52 - 1:57
    But perhaps before going onto that, it's worth going into some relatively commonsense things.
  • 1:58 - 2:07
    I would say that there are certain things that should ring alarm bells if people are advertising some sort of treatment for child dyslexia.
  • 2:07 - 2:13
    The first thing is if the intervention has been developped by somebody who has no academic track record,
  • 2:13 - 2:18
    no experience of doing research in this field, and hasn't published anything in this field,
  • 2:18 - 2:25
    if the intervention isn't endorsed by people in the mainstream dyslexia field,
  • 2:25 - 2:28
    that should also sound a note of caution.
  • 2:28 - 2:30
    Of course, the mainstream people aren't always right.
  • 2:30 - 2:33
    It's possible that somebody with no background will develop something marvelous.
  • 2:33 - 2:37
    But if that were the case, you would expect it to be pretty quickly picked up by people in the mainstream,
  • 2:37 - 2:41
    who are really, on the whole, pretty keen to find things that will work.
  • 2:41 - 2:48
    And you obviously want to look at whether somebody is asking for a lot of money for something that hasn't been proven.
  • 2:48 - 2:56
    And what is also, to my mind, a worrying sign, is if somebody promoting a treatment is relying heavily just on testimonials
  • 2:56 - 3:04
    from individuals who claimed to have been cured, rather than having any sort of proper scientific evaluation or kind of controls.
  • 3:04 - 3:11
    And it's worth noting that human beings have a tendency to be terribly impressed by testimonials,
  • 3:11 - 3:17
    and even myself, as somebody with a scientific training, I find if, you know, I've got headaches and somebody comes along and says:
  • 3:17 - 3:21
    "I was cured by such and such, and I went to my herbalist and it worked",
  • 3:21 - 3:27
    you know, you're often very tempted to be much more swayed by that sort of evidence than by a pagefull of numbers and figures.
  • 3:27 - 3:35
    And this just a human tendency: we are naturally built to really take advice from other people and to rely on what they tell us.
  • 3:35 - 3:38
    But in the contexts of these sorts of interventions, that's really quite dangerous,
  • 3:38 - 3:44
    because, when somebody gives a testimonial, that's just one person, their only individual experience,
  • 3:44 - 3:48
    And people you don't hear from tend to be the people who tried it, and it didn't work.
  • 3:48 - 3:52
    And you don't know how many of them there are: there may be thousands of them.
  • 3:52 - 3:56
    But they're not going to publicize the fact that they tried it and it didn't work.
  • 3:56 - 4:02
    And so, testimonials are often very much at odds with more scientific evaluations.
  • 4:02 - 4:10
    .... to turn out that when somebody says there is scientific evidence for what they're doing, how you should interpret that.
  • 4:10 - 4:15
    And that's jolly difficult even for scientists sometimes: there is disagreement - let alone for the general public.
  • 4:15 - 4:21
    But again, I think, there are some sort of general rules of thumb that you can go by
  • 4:21 - 4:24
    for telling that a treatment is likely to be effective.
  • 4:25 - 4:38
    And when I discuss this, I'm going to illustrate it by taking the example of the Dore treatment - that's DORE, named after Wynford Dore, it's originator.
  • 4:38 - 4:46
    ANd I'm picking on this largely because it is a non-mainstream treatment that isn't widely accepted by the experts,
  • 4:46 - 4:50
    and yet it does claim that there is some scientific evidence to support it,
  • 4:50 - 4:54
    which has lead the scientists to look at it quite critically and quite carefully,
  • 4:54 - 4:58
    which is what we would do with any scientific evidence that comes along:
  • 4:58 - 5:05
    once it's out in the public domain and published, people tend to go and look at it as carefully as they possibly can.
  • 5:05 - 5:12
    Now, the Dore method is interesting to us, because it does illustrate the case where there is disagreement
  • 5:12 - 5:15
    as to whether the evidence is showing that its' effective or not.
  • 5:15 - 5:21
    And so, what I want to explain is why it is the case that despite this published evidence,
  • 5:21 - 5:25
    most of the experts are not impressed of the efficacy of the Dore treatment.
  • 5:25 - 5:32
    But the general points that I'll make would apply to any other treatment that was out there, whether (?) there was evidence being produced.
  • 5:33 - 5:40
    So, first of all, what is the Dore method? Well, it's a method that has been proposed for curing problems
  • 5:40 - 5:45
    that are thought to originate in the part of the brain called the cerebellum, which is at the back of the brain,
  • 5:45 - 5:50
    and it was developed by Wynford Dore as a method for helping his dyslexic daughter.
  • 5:50 - 5:54
    He has written a book about the history of how this came to became (?) about,
  • 5:54 - 5:59
    and he was a classic instance of a parent who was rather desperate to help his daughter who, for many years,
  • 5:59 - 6:04
    had been through the educational system and failed, and was getting increasingly depressed.
  • 6:04 - 6:11
    And he tried various things, he talked to various experts, and he ended up with this program that's been put forward,
  • 6:11 - 6:16
    which is an individualized program, where the child follows various sorts of exercises,
  • 6:16 - 6:21
    which are done for about ten minutes twice a day, over quite a long period of time,
  • 6:21 - 6:25
    varying, depending on the severity of the problem, from maybe 6 months to 2 years.
  • 6:26 - 6:31
    And the child is assessed at regular intervals and different exercises may be prescribed.
  • 6:31 - 6:39
    Now, the theory behind the Dore method is that dyslexia and other learning difficulties -
  • 6:39 - 6:44
    it's not just dyslexia it claims to help, but also Attention Deficit problems ...(?) hyperactive -
  • 6:44 - 6:49
    are thought to arise within the cerebellum: the cerebellum just doesn't develop normally,
  • 6:49 - 6:54
    and the argument is that you can have different cerebellar impediments in different people,
  • 6:54 - 6:57
    and that's why you can get this range of different symptoms,
  • 6:57 - 7:04
    but that you can diagnose them by specific tests of test of mental and physical coordinations.
  • 7:04 - 7:13
    And what you are then supposed to do is these exercises, which are not anywhere fully described in the public domain,
  • 7:13 - 7:18
    because they are commercially sensitive, but there are some examples given, and it's clear that what they do
  • 7:18 - 7:23
    is focused largely on training balance and hand-eye coordination in children.
  • 7:23 - 7:30
    So you might be asked to stand on a cushion on one leg, or to throw a bean bag from one hand to another
  • 7:30 - 7:37
    while you are doing that, just stand on a wobble board (?) and balance, or to follow something with your eyes in a particular way.
  • 7:39 - 7:48
    So, the idea is that these are all things that the cerebellum is involved in, by training up the cerebellum, you may improve its general abilities.
  • 7:49 - 7:53
    So, what is the evidence for this underlying theory?
  • 7:53 - 7:58
    Well, it's not a proven theory, but there is some support for it.
  • 7:58 - 8:07
    Certainly, people trying to look at what is going on in the brain in dyslexia have proposed many different theories
  • 8:07 - 8:09
    about what the underlying causes might be.
  • 8:09 - 8:15
    If you look at the brain in a brain scanner of somebody with dyslexia, it typically looks totally normal.
  • 8:15 - 8:19
    There's certainly no big holes in the head or anything like that, that you are going to see on a scanner.
  • 8:19 - 8:25
    But the argument is being made that there may be regions of the cerebellum that are perhaps slightly smaller than they should be
  • 8:25 - 8:28
    or not functioning quite as they should be.
  • 8:28 - 8:34
    And this theory has some support, although not everybody would agree with it
  • 8:34 - 8:39
    and there is certainly other theories equally plausible at the moment that are around.
  • 8:39 - 8:45
    The notion - the cerebellum is important for getting things automated.
  • 8:45 - 8:51
    So you can - when you learn to drive a car, first of all, it's very slow and effortfull, and you have to think about everything you do.
  • 8:51 - 8:55
    By the time you are a skilled driver, it's no longe the case that you have to do that,
  • 8:55 - 8:58
    you just drive around without thinking about it.
  • 8:58 - 9:00
    You can do all sorts of other things while you are driving.
  • 9:00 - 9:07
    So, the argument is that with reading, most people, similarly, become very automatic in how they learn to read:
  • 9:07 - 9:15
    you do it without thinking about it, but for the dylexic it remains effortfull because the cerebellum is not functioning normally
  • 9:15 - 9:19
    and it's the cerebellum that helps you get your skills automatized.
  • 9:19 - 9:27
    And in support of this, it has been argued that in many people with dyslexia, there are some associated problems with motor coordination,
  • 9:27 - 9:33
    ..... (?) physical skills and so on, and that too could be a sign of a problem with the cerebellum.
  • 9:33 - 9:40
    Again, that's fairly controversial, it's not being found in all children, and the arguments go to and fro.
  • 9:40 - 9:47
    But this is not a sort of theory that is particularly disapproved of by the mainstream. People are debating it.
  • 9:47 - 9:55
    The difficult stumbling block, though, for the Dore approach to treatment comes with the idea that
  • 9:55 - 10:03
    if you train the motor skills, that is a sort of coordination between different muscles and movements
  • 10:03 - 10:09
    and between their eyes and hands, that this will somehow have a knock-on effect on things like reading.
  • 10:09 - 10:16
    And indeed, David Randall and colleagues, who published this initial study on the treatment,
  • 10:16 - 10:23
    describe it as something of a leap of faith, because the cerebellum is actually known to be a very complicated organ,
  • 10:23 - 10:27
    with lots of different regions, which are fairly independent from one another.
  • 10:27 - 10:35
    So there is no real reason to suppose that if you train one part of the cerebellum, it will have somehow a generalized benefit.
  • 10:35 - 10:41
    And indeed, you could say: "Well, if it were the case that this is true, if you'd had a chance, you would go to skateboarding,
  • 10:41 - 10:49
    or playing ping-pong, or things like that, ....... (?) or perhaps ballet dancing, things that require balance and coordination,
  • 10:49 - 10:53
    that should protect you against dyslexia". There is really not much evidence for that,
  • 10:53 - 10:58
    on the contrary, there is some very good sportsmen who - gymnasts and people with dyslexia.
  • 10:58 - 11:07
    So it is hard to see how the logic of saying "Train these motor skills and somehow the whole cerebellum function some day improves2
  • 11:07 - 11:13
    But what does the published evidence look like? Because the theory might be, you know, questionable,
  • 11:13 - 11:17
    but basically, what the parents are going to say is, "What matter is, does it work?"
  • 11:18 - 11:25
    Well, there is a published study on the intervention, which claims that it shows that it really does work
  • 11:25 - 11:28
    if you compare children who have the intervention and children who don't.
  • 11:28 - 11:36
    And two papers have been reported - one from the initial phase of the study, and the other from a subsequent phase -
  • 11:37 - 11:46
    And they are reported in the Journal of Dyslexia which, in 2003, published the first paper
  • 11:46 - 11:54
    which was on just under - started with a sample statistics on the 300 children who were all attending a .... (?) primary school.
  • 11:54 - 11:58
    And the researchers went in and screened all the children on the dyslexia screening test,
  • 11:58 - 12:01
    to pull out children who would be suitable for enrolment in the study.
  • 12:01 - 12:11
    But the first thing that is more important to note is that these were not children who had a very high rate of diagnosis of dyslexia.
  • 12:11 - 12:19
    So, there were 35 in the group, and about a third of those came out as having a strong risk of dyslexia on this dyslexia screening test.
  • 12:19 - 12:27
    Another 21% came out with a mild risk, but about half of these children were not really ...... (?) in this category
  • 12:27 - 12:31
    and they were just picked because their schools (?) were relatively lower compared to the other children.
  • 12:31 - 12:38
    And there were only a total of 6 children who had previously been diagnosed with dyslexia, out of the 35.
  • 12:38 - 12:43
    There were a couple with a diagnosis of dyspraxia and one with ADHD diagnosis.
  • 12:43 - 12:48
    So this is not really a sample consisting of children really with severe problems on the whole.
  • 12:48 - 12:51
    There were few in there with major difficulties.
  • 12:51 - 12:58
    Nevertheless, the originators of the treatment would argue even quite mild problems might be worth treating with this
  • 12:58 - 13:02
    and so you could argue this study is nevertheless of value.
  • 13:02 - 13:08
    So what they did, they started out well in this study: they divided the children randomly in treated and untreated groups,
  • 13:08 - 13:14
    which is, as I am going on to explain later, is an important part of a good study.
  • 13:14 - 13:21
    And if you look at the results that are described on the promotion materials of the DORE organization,
  • 13:21 - 13:28
    they are all in Dore's book that he published, "Dyslexia, the miracle cure", he described the results as stunning
  • 13:28 - 13:35
    and said that reading age increased threefold, comprehension age increased almost fivefold
  • 13:35 - 13:41
    and writing skills by what he described as "an extraordinary 17-fold".
  • 13:41 - 13:48
    Of course, everybody reading that think "Wow, my child is going to take off like a rocket if we put him on this intervention."
  • 13:48 - 13:57
    But unfortunately, these figures are really a classic instance of how statistics can be manipulated in a very misleading way.
  • 13:57 - 14:05
    So, for a start, they were not based on any comparison between the control children and the untreated children -
  • 14:05 - 14:09
    sorry, the control children and the treated children.
  • 14:09 - 14:18
    They were - instead, they just took all the children who would be treated and looked at how they did on a group reading test
  • 14:18 - 14:21
    that had been administered by the school every year.
  • 14:21 - 14:31
    And the children had had this on two occasions prior to the intervention - so, 3 months before it started and a year before that -
  • 14:31 - 14:35
    and on two occasions after the intervention, after this whole long 4-year period.
  • 14:35 - 14:44
    And what the researchers did was to really just plot the average schools of the group over these 4 time periods
  • 14:44 - 14:50
    and show that if you compared the amount of change from the first time point to the second,
  • 14:50 - 14:54
    which was before they had had any treatment, it was a certain amount
  • 14:54 - 15:00
    and if you then compared the second to the third time point, so the treatment had been going on (?) between those two,
  • 15:00 - 15:03
    there was a different amount of change.
  • 15:03 - 15:07
    And then they divided one by the other and showed that there was this threefold improvement.
  • 15:07 - 15:13
    But it's a very, very misleading way of depicting these data, because if you look at them on a graph, here,
  • 15:13 - 15:18
    you can see that the only odd thing about the data - well, there's two odd things about the data:
  • 15:18 - 15:23
    one is that at most time points, these children are reading at absolutely normal levels.
  • 15:23 - 15:27
    So it's not clear why they are regarded as having risk for dyslexia;
  • 15:27 - 15:33
    and the one time point when they're not, is the time point 3 months before they are involved in the study,
  • 15:33 - 15:39
    where there is a bit of a drop. But it's really not an impressive demonstration of change
  • 15:39 - 15:47
    and this division of one time period by another is very misleading, because it just gives double weighting
  • 15:47 - 15:52
    to this one low period of three months before the treatment started.
  • 15:52 - 15:58
    And they did the same thing again with these other figures of massive increases that they talk about,
  • 15:58 - 16:07
    using data from the SATS tests administered by teachers, which are not really regarded as particularly precise or rigorous tests,
  • 16:07 - 16:14
    and really group children in a fairly global way at level 2, 3 or 4.
  • 16:14 - 16:20
    Level 2 is average for 7 year old, 3 is average for 9 year old, and 4 is average for an 11 year old.
  • 16:20 - 16:28
    And to give you an idea of the sort of misleading nature of these massive changes they talk about,
  • 16:28 - 16:34
    on the writing test, where there is this incredible change that they talk about, of a 17-fold increase,
  • 16:34 - 16:41
    the score at age 8, the average score was 2.5, which is about what you'd expect from a 8 year old.
  • 16:41 - 16:47
    At age 9, it was 2.56, which is a little bit better, but not much.
  • 16:47 - 16:53
    And then, they argue, the intervention came in, and at age 10, the children scored 2.95.
  • 16:53 - 16:57
    They are still rather below where they ought to be at the age of 10.
  • 16:57 - 17:01
    It looks as if on this particular writing assessment, the children were just rather creeping along.
  • 17:01 - 17:10
    But because the difference between 2.53 and 2.56 is less than the difference between 2.56 and 2.95,
  • 17:10 - 17:18
    they make a big computation of dividing one by the other, actually coming out with the number 17, which is a wrong number (?): it's actually 13.
  • 17:18 - 17:25
    So there is a 13-fold change. But if you look at the overall numbers, this is really not so an impressive game at all.
  • 17:25 - 17:28
    It's really a very misleading way of presenting the numbers.
  • 17:28 - 17:37
    So, most people would say, this is really smoke in mirrors in terms of using statistics in a way that isn't really valid.
  • 17:37 - 17:42
    The other thing that is of notice is that all these results that have given so much publicity
  • 17:42 - 17:48
    in promoting the treatment about these massive changes, haven't talked about the control group at all.
  • 17:48 - 17:51
    They've just talked about, "Well, we've got these children, before treatment they did this,
  • 17:51 - 17:54
    and after treatment they did that, and it has all gone up".
  • 17:54 - 18:00
    And of course, if schools do go up after treatment, it's not necessarily because the treatment works:
  • 18:00 - 18:02
    There are lots of other reasons you need to bear in mind.
  • 18:03 - 18:08
    And the first of which is just, on some things, you get better because you get older,
  • 18:08 - 18:14
    so that if you were to measure shoe sizes before the DORE treatment and after it, it would go up,
  • 18:14 - 18:17
    but it wouldn't mean that it made your feet grow bigger.
  • 18:17 - 18:24
    Now, clearly, that's a silly example in most cases, because people try to use measures that don't necessarily change with age,
  • 18:24 - 18:27
    or that are adjusted in some way for age.
  • 18:27 - 18:32
    But it's important to bear that in mind when people are talking about changes on things like -
  • 18:32 - 18:38
    the DORE program, they talk about changes on balance, balance improves dramatically after the program.
  • 18:38 - 18:43
    These are measures that have not been adjusted for age at all, and so, some of these changes could well be due to the fact
  • 18:43 - 18:48
    that the children are getting older and getting better at doing these things because of that.
  • 18:48 - 18:56
    Another uninteresting reason why schools may improve is that the children may be having some other sort of special help.
  • 18:56 - 19:03
    So, if a child is having reading difficulty, they may very well be getting some special help at the school, in addition to following this program.
  • 19:03 - 19:10
    And that may be what's causing the change, rather than the particular intervention you are interested in.
  • 19:10 - 19:15
    What's very well known, of course, is the placebo effect, which is a sort of concept coming from medicine,
  • 19:15 - 19:21
    which also says that you can get better just because you think you are going to get better, because you think somebody has done something effective.
  • 19:21 - 19:26
    And in the case of educational treatments, you can see effects where -
  • 19:26 - 19:32
    because the teachers and the parents and the children themselves are all full of expectations of how this is going to improve them -
  • 19:32 - 19:39
    there is more motivation: everybody gets positive attention and this itself can cause positive effects.
  • 19:40 - 19:46
    The fourth reason, which is often neglected, because it really doesn't affect things in medicine so much,
  • 19:46 - 19:50
    but in education, it's actually rather important, using the sort of thing like reading tests:
  • 19:50 - 19:56
    you can have practice effects. So you can get better upon some things, just because you've done it before.
  • 19:56 - 20:01
    And we've seen this quite a lot with language tests, for example, that we give to children,
  • 20:01 - 20:06
    where, the first time you test a child, they don't know what to expect, they don't know what's coming,
  • 20:06 - 20:10
    you aske them to do something that's unfamiliar and they are a little bit nervous, maybe.
  • 20:10 - 20:16
    You test them again on the same thing a month later: they are much, much better, simply because they've done it before
  • 20:16 - 20:20
    and they are calmer about it, they know what to expect, and so on.
  • 20:20 - 20:26
    So you can get practice effects that can make quite a difference, just because you know what to expect
  • 20:26 - 20:30
    and you are familiar with the whole situation of the test.
  • 20:30 - 20:38
    The fifth reason - and the last one, you'll be pleased to hear - why people may improve for no good reason
  • 20:38 - 20:43
    is the hardest to explain and it's something known as regression to the mean,
  • 20:43 - 20:49
    and it's just a statistical artefact, which has to do with, if you pick somebody because they're bad at something,
  • 20:49 - 20:54
    the odds are, when you test them on a second occasion, they'll be a little bit better (?).
  • 20:54 - 20:59
    The converse is also true: if you pick somebody who is very good, they tend to get a little bit worse when you test them a second time.
  • 20:59 - 21:09
    Why should that be? The reason why this occurs is because our measures are not entirely perfect an accurate -
  • 21:09 - 21:13
    I'm showing a graph here, where we have a measure that is almost perfect,
  • 21:13 - 21:22
    and you test people on two occasions, and you just will see that their scores on time 1 and time 2 are identical: we are assuming that there is no genune change.
  • 21:22 - 21:27
    If you do that, then you don't get regression to the mean, because the measure is perfect
  • 21:27 - 21:31
    and if you test them a second time, they'll get exactly the same sort of score.
  • 21:31 - 21:40
    And what you can see on the right hand side of the graph here, is people divided up according to the average score they started with.
  • 21:40 - 21:45
    So we've put people into groups who were very poor to start with, who were medium, less good and so on.
  • 21:45 - 21:49
    And these are just fictitious data made up to illustrate the point.
  • 21:49 - 21:56
    So you just generate these numbers by saying, "We've got a measure that has this particular characteristic
  • 21:56 - 22:01
    that if you measure on one occasion, on another occasion it remains pretty much the same".
  • 22:01 - 22:07
    So then, you don't get regression to mean and you get people to maintain their position across time.
  • 22:07 - 22:10
    So if you then see change, you can say "Well, it's genuine change."
  • 22:10 - 22:16
    But most of our measures are not like that, most of our measures are not perfectly correlated:
  • 22:16 - 22:22
    that means, you measure them on one time, and another time, and they actually change because of all sorts of things.
  • 22:22 - 22:30
    Things like the particular test items that you're using, whether you are in a good mood, whether you've made a lucky guess in some items.
  • 22:30 - 22:36
    And what you can see is that if you do that, that some people's scores go up with time, some people's go down with time.
  • 22:36 - 22:45
    But on average, if you start with a low score, the odds are, you come a little bit closer to the average when you are tested on another occasion.
  • 22:45 - 22:48
    If you start with a high score, you get a little bit worse.
  • 22:48 - 22:54
    And this is nothing to do with genuine change: it's just to do with the fact that our measures are imperfect.
  • 22:54 - 23:00
    And it has been argued that this is a major reason - all sorts of treatments that work (?) but don't really work.
  • 23:00 - 23:04
    It's just that it looks as if you've seen a change, and you tend to attribute it to the treatment.
  • 23:04 - 23:10
    Now, this sounded very depressing, because it means there's all sorts of reasons why we can see change,
  • 23:10 - 23:15
    and how do we distinguish whether we've got a genuine change due to our treatment?
  • 23:15 - 23:21
    But the fact is that you can control for most of these things if you do a study that has a control group.
  • 23:21 - 23:31
    That's why those who are trying to do scientific evaluations are really keen to include control groups in studies and argue that they are essential.
  • 23:31 - 23:37
    Because if you have another group of children who have been selected to be as similar as possible to your treated group,
  • 23:37 - 23:42
    and are the same tests before and after the period where the treated group are treated,
  • 23:42 - 23:49
    you are actually controlling for the effects of maturation, the effects of any other intervention they might be having,
  • 23:49 - 23:53
    practice effects in particular, and also this dreadful regression to the mean.
  • 23:53 - 23:56
    All of those things can be then taken into account.
  • 23:56 - 24:02
    And in so far as they have effects, what you would expect to see is that you may see improvement in your control group
  • 24:03 - 24:07
    because of these spurious things that we don't really want to see.
  • 24:07 - 24:13
    And then you can say, "well there is more improvement in the treated group" (?) and it is that difference that is really critical.
  • 24:13 - 24:21
    It doesn't actually control to use - if you have a group who have not been given any treatment - it doesn't control for placebo effects.
  • 24:21 - 24:28
    So you've still got the problem that maybe your treated group will improve just because everybody is focusing on them with great excitement.
  • 24:28 - 24:33
    But you could actually also have control for that, and it's becoming increasingly popular in this field
  • 24:33 - 24:38
    to say that what you should have is a control group who are actually given some alternative treatment.
  • 24:38 - 24:43
    So, for example, if you are interested in a treatment that might improve reading,
  • 24:43 - 24:48
    you could either get children some standard educational treatment that they are getting anyway
  • 24:48 - 24:54
    So if your claim is that you are doing better than a phonological-based treatment,
  • 24:54 - 24:58
    you could have a control group given that treatment and see if you are making really that much difference,
  • 24:58 - 25:03
    or you might prefer to say, "Well, let's treat something else, let's give children training in something completely different
  • 25:03 - 25:07
    that isn't focused on reading, but nevertheless could benefit them in other ways."
  • 25:07 - 25:10
    And then you can do that sort of comparison.
  • 25:10 - 25:18
    So what about the DORE study, because I mentioned at the outset, when talking about this study, that they did have a control group.
  • 25:18 - 25:24
    But so far, talking about the results, are only mentioned (?) the dramatic changes that they saw,
  • 25:24 - 25:27
    which ignored the control group.
  • 25:27 - 25:35
    The interesting thing is that when you look at their control group, it illustrates perfectly the importance of having a control group.
  • 25:35 - 25:40
    So, on they dylexia risk's score, where a high score is bad,
  • 25:40 - 25:47
    they had a change in the treated group, from 0.74 to 0.34.
  • 25:47 - 25:51
    So you think: "Wow, that's great, these children's risks for dyslexia have really come down."
  • 25:51 - 25:56
    In the control group, the average score changed from 0.72 to 0.44.
  • 25:56 - 25:59
    Now, you could say: "Well, it's not so big a change."
  • 25:59 - 26:04
    The trouble is, with groups this size, you can't really tell whether that's meaningful.
  • 26:04 - 26:08
    But certainly, what is clear is that both groups improved on the dyslexia screening test,
  • 26:08 - 26:12
    even though the control group had not had the intervention.
  • 26:12 - 26:17
    So, it really illustrates the point very clearly that on a lot of these measures,
  • 26:17 - 26:21
    everybody gets better, even if they are not treated.
  • 26:22 - 26:31
    Now, if we look at the more precise data that they presented, they presented average scores on the different subtests from the dyslexia screening tests,
  • 26:31 - 26:36
    I won't talk about all of them, I have got a fuller presentation
  • 26:36 - 26:39
    where I do talk about all the different measures they use
  • 26:39 - 26:43
    and I don't want to sort of be accused of delberately hiding things,
  • 26:43 - 26:46
    but I think the tests that people would be most interested in are the literacy tests.
  • 26:46 - 26:53
    So, you undertake the DORE treatment because you want to get better at reading and writing, if you are a parent of a dyslexic child, at any rate.
  • 26:53 - 27:03
    So, looking at the results on those tests, what they found was that there were a total of 4 tests that had to do with literacy directly.
  • 27:03 - 27:08
    And on one of those, it looked as if the treated group did better than the untreated group.
  • 27:08 - 27:14
    But there is a problem with that, though, because on this reading test, the untreated -
  • 27:14 - 27:20
    the control group are actually right on the average score for their age at the start of the treatment - at the start of the study.
  • 27:20 - 27:27
    So, in a sense, you could argue, "Is there really room for improvement ...... (?) school absolutely average,
  • 27:27 - 27:35
    whereas it just so happened that the children who had treatment started a little bit lower and therefore had more improvement.
  • 27:35 - 27:39
    And their improvement was not dramatic, one has to say as well.
  • 27:39 - 27:43
    Their school went up from 3 to 3.5, on a scale of 0 to 10.
  • 27:43 - 27:52
    On the other measures, again it illustrated that on two of them, everybody improved, regardless of whether they had the treatment.
  • 27:52 - 27:55
    And on the third one, nobody changed very much at all.
  • 27:55 - 28:03
    So, this is not dramatic evidence of improvement but you could argue: "Well, nevertheless there was one measure that looked a little bit promising."
  • 28:03 - 28:12
    But they then, in the second phase of the study, went on to give the control group the same treatment, and they published this in 2007.
  • 28:12 - 28:16
    So we now don't anymore have a control group as everybody has been treated:
  • 28:16 - 28:22
    one group early on, and the other group with a delayed time scale.
  • 28:22 - 28:30
    And they presented the data between time 1 at the start of the study and right at the end of the study, when everybody had had this treatment.
  • 28:30 - 28:38
    But when you look at the results there, it's clear that there really is a, you know, no persistent improvement in reading.
  • 28:38 - 28:42
    In fact, the mean scores for the children having the delayed treatment on the reading test
  • 28:42 - 28:45
    have now really gone down, rather than up, at the end of treatment.
  • 28:45 - 28:51
    And the general impression, I would say, is that there is nothing very stunning going on here,
  • 28:51 - 28:58
    certainly nothing that matches the description that you get on the promotion materials for the intervention.
  • 28:58 - 29:08
    So, overall, I would argue that the evidence for gains associated with this treatment is really not at all compelling.
  • 29:08 - 29:17
    First of all, the claims that are made for stunning changes are all coming from analyses where they didn't incorporate the controls
  • 29:17 - 29:22
    and they just tried to argue that any change you see at the time must be due to the treatment.
  • 29:22 - 29:25
    and not taking into account all these other factors.
  • 29:25 - 29:30
    And on reading measures, where there was control group data available,
  • 29:30 - 29:37
    there was an initial small gain in the treated group, but it wasn't sustained by the end of the study.
  • 29:37 - 29:41
    So, it really doesn't look terribly promising.
  • 29:42 - 29:47
    Now, this is why in general, I think it's true to say this:
  • 29:47 - 29:53
    I don't know of anybody in the dyslexic community who is an advocate - in the academic community
  • 29:53 - 29:58
    who is an advocate of the DORE treatment, other than people that are directly associated with the DORE organization.
  • 29:58 - 30:05
    And so, the reason really is just that the evidence is not at all compelling,
  • 30:05 - 30:09
    although the study was small and you could argue a larger study should be done.
  • 30:09 - 30:15
    There is a real mismatch between the claims that are being made and the evidence that is available.
  • 30:15 - 30:22
    But the interesting thing is also why so many people seem to nevertheless regard this as an effective treatment.
  • 30:22 - 30:30
    If the testimonials are to be believed, there are many satisfied customers and happy parents who feel that their children have been helped.
  • 30:30 - 30:36
    I think there is quite an interesting set of reasons why this may be so.
  • 30:36 - 30:41
    And one is that there is a well known - in the psychological field - well known human tendency
  • 30:41 - 30:47
    to think that something that you've put in a lot of time and money too, was worthwhile.
  • 30:47 - 30:56
    It's called cognitive dissonance, and it means that if you've actually put in the effort, you tend to feel that there was an effect.
  • 30:56 - 31:02
    You have to somehow resolve this sort of inconsistency, otherwise, in your mind.
  • 31:02 - 31:07
    And this was beautifully illustrated, not by the trial of the DORE treatment, but in another trial,
  • 31:07 - 31:11
    which was a very nicely well-conducted trial of something called Sunflower therapy,
  • 31:11 - 31:19
    which is a rather holistic approach to intervention for dyslexia that involves kinesiology and physical manipulation,
  • 31:19 - 31:23
    massage, homeopathy, herbal remedies and neurolingusitc programming.
  • 31:24 - 31:30
    And there was a very rigorous study done for this, and what was interesting about it
  • 31:30 - 31:39
    was that, like so many of these things, they didn't really find a lot of evidence for any better change in the clinical versus the control group,
  • 31:39 - 31:43
    although, to some extent, both groups were securing (?) their schools were improving.
  • 31:44 - 31:50
    What they did find, though, is that the children themselves had higher self-esteem if they had undergone the Sunflower treatment,
  • 31:50 - 31:56
    but that also, 57% of the parents did think that Sunflower therapy was effective in treating their child.
  • 31:57 - 32:04
    So there is a clear mismatch between what the study showed of the objective evidence on the children's learning difficulties,
  • 32:04 - 32:07
    and what the parents actually thought.
  • 32:07 - 32:12
    It is possible that this could be related to the fact that the children's scores did improve,
  • 32:12 - 32:18
    but if you didn't know that the control children had also improved, you might attribute that to the therapy -
  • 32:18 - 32:24
    but also to the fact that people were again being given a lot of encouragement,
  • 32:24 - 32:30
    there was a lot invested in that treatment, and then there might well (?) have been some sort of sense of cognitive dissonance there.
  • 32:30 - 32:41
    There's also a strong human tendency to be impressed by certain kinds of explanation that get more biological about dyslexia,
  • 32:41 - 32:49
    particularly those such as the DORE treatment that get more neurological and claim to be doing something to the brain in treating dyslexia.
  • 32:49 - 32:54
    There was a beautiful study done - published - in 2008, not on dyslexia,
  • 32:54 - 33:00
    but just more generally on people's tendency to be impressed by scientific eyplanations.
  • 33:00 - 33:09
    and what these researchers did was to give people explanations of psychological phenomena that are well known
  • 33:09 - 33:14
    and they either gave them a good explanation or they gave them a not very good explanation
  • 33:14 - 33:21
    that was more like just a re-description of the effect, and asked people to judge whether this was a good explanation or not.
  • 33:21 - 33:26
    And what was fascinating about this study was that in general, people were quite good at doing this:
  • 33:26 - 33:33
    even if they had no familiarity or background in psychology, they could distinguish a good explanation from a bad one.
  • 33:33 - 33:40
    But what they found was that if they added some verbiage that just talked about the brain in various ways,
  • 33:40 - 33:45
    and said, "This result came about because brain scans showed it", or "because we looked at the frontal lobes",
  • 33:45 - 33:48
    people were much more impressed with the bad explanations.
  • 33:48 - 33:53
    So a good explanation didn't get any better when you added all this neuroscience waffle,
  • 33:53 - 33:59
    but if you added neuroscience waffle to a bad explanation, people thought it not so bad.
  • 33:59 - 34:06
    And so, there is a tendency to be very impressed by anything that talks about, adds the brain in to an ........ (?) explanation.
  • 34:06 - 34:13
    And I think this is used by people who then try and add spurious neuroscience sometimes
  • 34:13 - 34:18
    to their accounts of their particular promissing theory.
  • 34:18 - 34:24
    And it really is not - we shouldn't allow ourselves to be mislead.
  • 34:25 - 34:34
    So I think, to sum up, there are a number of barriers to objective evaluation of intelligence,
  • 34:34 - 34:38
    which, to some extent, functions about (?) our human condition,
  • 34:38 - 34:44
    that we are not naturally good at taking in lots of numbers and looking at graphs
  • 34:44 - 34:48
    and trying to sort of take into account alternative explanations.
  • 34:48 - 34:53
    We tend to be impressed when we hear other people tell us that something has worked
  • 34:53 - 34:57
    and it's hard - you have to almost guard yourself against the tendency to do that
  • 34:57 - 35:02
    and to look rather for the hard evidence, to look for the actual numerical data.
  • 35:03 - 35:08
    We have to be very careful when people start giving us explanations that have got a lot of neuroscience in them
  • 35:08 - 35:12
    and check out, is this real neuroscience or is it just put in there to impress us?
  • 35:14 - 35:20
    We have to be aware of the effect of cognitive dissonance and the tendency to believe some things
  • 35:20 - 35:24
    simply because we have invested time and money in it
  • 35:24 - 35:31
    and, most importantly, we have to bear in mind that there will be effects on children's performance
  • 35:31 - 35:38
    of maturation, of our expectations, of just get practising on things,
  • 35:38 - 35:43
    and there are also these dreadful statistical artefacts that can make it look as if a change has occurred,
  • 35:43 - 35:46
    when it's really not particularly impressive.
  • 35:46 - 35:50
    But I think, if one bears these things in mind, the bottom line is really:
  • 35:50 - 35:55
    "Look for evidence from studies that have got adequate controls"
  • 35:55 - 36:02
    and if you do, you'll be in - a standard, I think, by how far you can see improvements in children, even if they haven't had the treatment.
  • 36:02 - 36:06
    and there are lots of things that will make things a lot better, just with the passage of time.
  • 36:06 - 36:11
    But if you really want to demonstrate that there has been an effective treatment,
  • 36:11 - 36:16
    you do have to show an improvement relative to a control group,
  • 36:16 - 36:21
    rather than just, somebody started out not so good and is now a little bit better after the treatment.
  • 36:21 - 36:30
    I hope that that might give you some useful indicators when trying to look at new treatments that are out there and on offer,
  • 36:30 - 36:35
    and for a more detailed account of some of this work, there are various -
  • 36:35 - 36:40
    there is a powerpoint presentation with notes on my website on this topic.
Title:
Dorothy Bishop: Evaluating Alternative Solutions for Dyslexia
Video Language:
English

English subtitles

Revisions