Wednesday, December 23, 2009

My reply to Leys' reply

Here is my reply on Leys' reply on my post of him being sloppy on science:

On the first point, I am thinking of Kate Watkins et al who, on the 10th of October, 2007, published the following in Brain: 'Our data support the conclusion that stuttering is a disorder related primarily to disruption in the cortical and subcortical neural systems supporting the selection, initiation and execution of motor sequences necessary for fluent speech production'. I accept, as do most other people, that many other factors contribute, particularly as time goes by, and these can turn stammering into a kind of syndrome. But none of that detracts from the view that the ROOT CAUSE of stammering is a neurological condition, a kind of faulty wiring in the brain.

As I wrote, I do not disagree about there being an underlying neurobiological issue, but you exclusively talked about the neurological aspect. However, stuttering symptoms are so diverse and fluctuate significantly that a pure neurological explanation is not enough. Moreover, cognitive beliefs and social anxiety make up a great part of the handicap. Watkins or any other neuroscientist have not explained the symptoms of stuttering. My
guess is that many symptoms are learned behaviours and even stuttering events could be learned. I just think it is unwise to just insist on a neurological underlying cause but not mention in the same breath learned and cognitive aspects. My advice: never exclusively talk about neuro when talking about stuttering. And emphasize that a change is hardly coming from neuro changes but from psychological work.

On the second point, about the efficacy of Early Intervention, there is a little less science, I grant you. If only Stammering World had more money to do more research we could be more, or less, certain. I know that it may not always be easy to find a speech and language therapist who specialises in paediatric stammering, but there is a growing number in the UK who have the necessary skills. And we are training more because we, and now the Government, believe that there is a sufficiently large body of clinical evidence, and agreement amongst specialists, that Early Intervention with young children who stammer - that is as close to onset as possible - is not only desirable but essential.
Oh well the government. Didn't they also believe in WMD? As I said many times before, the results are not
that great when compared to natural recovery, in fact statistically not different. Why don't you read the Lidcombe follow-up study and you will find that the relapses are there. And given the absolute low understanding of statistics and research design, the experts' opinions are suspect. They are experts in treatment not research!
You and your readers may want to go to where you will find the BSA's recent report, 'Every Child's Chance of Fluency'. Take a look at the appendices, which summarise the research case for Early Intervention. Daniel Hunter, the therapist who the BSA chose to train SLTs in Early Intervention, has a 98.5% success rate and his achievements were officially recognised in 2008 by the Royal College of Speech and Language Therapists. You should have asked Daniel about this at the recent reception in the place you felt you could not mention. And there were several other leading therapists in the room who would have been happy to say that they have achieved similar results in recent years.
Did you include the Lidcombe follow-up study? The only long-term study! I did talk to Daniel, because he promised me to show the data for the last 2 years. Has he spoken to the kids again after a few years? How do they speak now? What is the sample size? You need to look at the long-term. Do the therapists meet the kids against 2-3 years later?

I am happy to argue on a purely theoretical basis that kids who would not have recovered have a better control of their fluency and less secondary symptoms and cognitive unhelpful beliefs. But they are not really cured in my view. And there is no proper empirical evidence.

On the third point, about how Early Intervention is effective because the faulty wiring in a young child's brain has not yet hardened up, I think this is a reasonable, short-hand attempt at explaining why the success rate of therapy in terms of overcoming stammering drops away at around the age of six or seven. But we at the BSA are not beholden to any one model, so we will keep an open mind. However, I’m sure you know that this general association between the benefits of Early Intervention and neurological plasticity applies to conditions other than stammering.
Yes, but most kids would have recovered anyway? It is not clear at all that the wiring has improved, maybe they have just learned to take blocks more easy? I would not address this point. I would rather say that at a young age behaviours can be more easily corrected.

Also, Tom, you make a number of points which I think you need to clarify. You say, for example, that ‘a lot of stuttering behaviour is learned, re-enforced, and kept alive by an underlying neurological issue’. You may well be right, but where is your evidence for this? And what, in scientific terms, is ‘a lot of stuttering behaviour’? And, although I probably part-agree with you, where is the evidence for saying that ‘a stuttering event is often not due to the neurology at that precise moment but environmental or internal stimuli triggering stuttering behaviour’? Similarly, can you support the statement that ‘controlling stuttering will mostly involve changing the cognitive behavioural aspects rather than the neuro’? And finally, can you please tell us how this interaction between neurological plasticity and neurological reorganisation works in brain terms?
First of all, people who stutter all show different stuttering symptoms in different circumstances. Why? It is very likely that they have individually learned this and it is not (just) a consequence of their neurological issue. Then different people stutter on different words, situations, or people. They must have learned this association. It is plainly obvious to me and I cannot see how it is not obvious to someone else who met many different stutterers. Now, imagine we magically put a normal speech center in our stuttering brain. Would we immediately not stutter anymore? I would say a clear no! We still have our learned behaviours and triggers, and they will lead to blocks and other symptoms. But what will happen is that we will speak more fluently most of the times and under stress, and slowly our brain will loose the associations because many times we will not stutter and our brain will not associate the stimulus with stuttering..

Changing behaviours of a person means either having to change the environment, the body, or the information stored withing our brain like our beliefs and memory on how to execute individually learned behaviours. Changing the environment and the body (e.g. the brain itself) is very difficult, so we need to change our beliefs and individually learned behaviours. Medication for example changes the body, but that's not yet a feasibly option. And that's what psychotherapy or speech therapy does, we are changing our  information. For example, we change a belief "I must avoid stuttering at all costs" to "If I couldn't avoid stuttering, it's OK and rarely does my environment react negatively." For example, we have an association of stuttering to a feared word, and we cancel this association by praticising the word in many different situations. There is NO NEUROLOGICAL REORGANISATION OR PLASITICITY INVOLVED. The brain just changes its connections slightly but the overall structure of the brain and its neurons is still there. That is very different from re-organisation after a brain stroke killed of neurons. In short: brain regions is dead, others take off. Compare this to: brain region stores faces, brain region stored more faces or unseen faces fade from memory. Yes, the brain is physically changing but just the strength of connections within the same region.

Look at computers. Neuroplasticity is when a region of the computer processor is broken another part will take over the processing. Learning is just: changing the information stored on the hardware. Yes, there the hardware is also changing but just the 0 and 1 flips representing information.

1 comment:

Anonymous said...

Tom, you still haven't cited where you are getting the evidence for your response, in the last part of this post. I would be interested to know if these are published facts you are reproducing or just your own pet theory.