Monday, December 21, 2009

Per Alm: Battle of The Stuttering Brains

Here is an edited transcript of a Skype debate I had with Per Alm: click on Read More below to read all! That is a good scientific debate for me, much like the debates that I had and am having with friends who are top scientists at top universities, and very unlike what you hear at most stuttering conferences. There you hear buzz words, parroting, self-congratulations, no talk about weaknesses of own models or mistakes, consensus-seeking, and lots of pseudo-scientific bla bla bla.

Tom: There are two issues in stuttering in my view
Tom: 1) to obtain an overall framework within to fit the disorder
Tom: 2) to look at what goes wrong in a specific individual from gene to symptoms.
Tom: your focus is on 2)
Per: And 3 -- what to do about it.
Tom: ok... that's too real-life for me :-)
Per: my main focus is on 1 but in that work I also look at 2, because the empirical data is in 2 (but also on clinical implications)

Tom: so i would say there is a theory of stuttering and a theory of why an individual stutters.
Per: Yes, I agree
Tom: i argue that the theory of stuttering needs to be vaguer because it needs to accommodate different causes and different symptoms
Per: yes, to capture what is common in all cases of stuttering
Per: In my current thinking the core is an impairment of the initiation of speech motor segments, looking at speech as a motor sequence
Tom: for me too but i would say an abnormally long delay in speech initiation. I guess impairment is more general
Per: I'm thinking more in terms of specificity of activation, and lack of specificity -- and that a delay in the system rather is secondary
Per: There is also a "1b": theories providing more detailed explanation of subgroups. For example, the possible subgroup with overactive dopamine system.
Per: Or maybe it is better to look at it as contributing factors rather than subgroups, because most subgroups are unlikely to be distinct.
Tom: yes there is 1b
Tom: one can talk about theories to varying degrees of approximation
Tom: i would also talk about a decoupling of underlying causes leading to X and X leading to reactions.
Tom: X being the impairment of speech motor segments.
Per: yes, I would agree. But one problem is that today it is very difficult to know where to draw the line between the underlying cause and reactions
Tom: what i would like to know is the proportion of learned behaviours that contribute towards stuttering events
Tom: 1) in frequency.
Tom: 2) in shape.
Tom: 3) in proportion.
Tom: compared to a purely neurological stuttering.
Tom: i would not be surprised if stuttering is caused by X or/and a trigger from learned behaviours
Per: very difficult to disentangle, but my guess is that many persons writing about stuttering today underestimate the neurological part
Tom: yes and no.
Tom: 1) i believe that a small disturbance (e.g. a marginally longer delay in speech initiation) can lead to an disproportionally strong reaction. so no need for severe dysfunction
Tom: so yes neuro is necessary but not necessarily strong. in that most stuttering is due to neurology.
Tom: if you dont have the neuro part, you dont stutter but your stuttering is not mostly neuro but learned behaviours (reactions to neuro)
Tom: 2) the neuro part is influenced by the brain's general state which is influenced by learned association like fear or panic triggers.
Per: Well, but how do you know?
Tom: I just know, Per. ;-)
Per: :-)
Tom: 1) non-linear effects is a general phenomena in many areas: think of traffic jams, a bit more of traffic and you have a much longer traveling time.
Tom: 2) i am not saying it is happening but it is plausible. AND saying it does NOT happen, needs an explanation, too.
Per: A problem is to say what is learned and what is neurological. Using a neurological function in an erroneous way for long may well lead to plastic changes. Is this resulting state neurological or learned? Well, in a way it is both.
Tom: yes but with a different twist
Tom: 1) basic wiring is not changing rather the strength or more neurons are participating.
Tom: 2) all learned behaviours change the hardware. the question is whether it can be changed back.
Tom: think about pizza delivery service!
Tom: after a critical waiting period, your responses non-linearly expand with more waiting time.
Tom: we probably have a critical waiting period after which we get suspicious, and pws due to neuro breach this more often and longer. this leads to disproportioned reaction.
Tom: I guess what my key statements are.
Tom: 1) there is an X for all pws
Per: I have two arguments for a high degree of neurological basis in "reactions":
Per: 1) When looking at accessory muscular tension in different cases it is often very specific, for example some cases only showing tension in the lower half of the face, with "cool eyes", and other showing more general spread of tension. The lower and the upper half of the face are innervated by different pathways/nuclei, it seems possible that this difference reflects basic differences in the underlying neurology between the cases.
Per: 2) There are examples of stuttering in adults becoming radically improved or aggravated by drugs, in ways which to me suggest strong neurological basis.
Tom: questions of clarification:
Tom: re 1. why can this not be learned behaviours? different subsets react differently. some subtypes show the same type of reaction in other activities and the general population, too?
Per: I can not provide evidence, and neither can you... ;-) At the present state it is speculation. Can you come up with any observation that would falsify your proposal?
Tom: you are saying that some symptoms of stuttering are part of the neurological issue whereas i say that the symptoms are reactions to neuro but there might be subtypes on how they react of neuro leading to X
Tom: so the neuro causes stuttering and at the same time some symptoms automatically and not learned.
Per: well, that seems like a reasonable interpretation of what I wrote -- but I think my main point is that we really can not say very much about this with certainty at the present state -- it is truly difficult to disentangle what is "reactions" and what is "neurological". However, I think that the current research on stuttering and the brain rather indicate that neurological factors remain important in adults who stutter, possibly becoming more complex after years of erroneous use of this brain system.
Tom: There needs to be the neuro stuff - a system that leads to abnormally long delay in speech initiation to keep the learned behaviours alive.
Tom: however, this does not need to be the main component of stuttering, because a small amount can disturb a system.
Tom: it is not influenced by developmental and environmental factors, but still rests on its original constitutional neurological issue to keep learned behaviours alive by leading to abnormally long delay in speech initiation modulated by brain chemicals (general level and emotions triggered by learned behaviours)
Tom: a bit of jamming every here and there keeps the learned behaviours alive.
Tom: my point is you do not need jamming at each stuttering instance to keep learned behaviours alive
Per: OK!
Per: That is an interesting point
Per: Is there a need for a neurological "happening" at each instance of stuttering? My guess is that there is at each instance of stuttering
Tom: i say clearly no
Per: :-)
Tom: ah here we disagree :-)
Tom: the brain has learned the motor code of stuttering so stuttering occurs either
Tom: 1) neuro jamming
Tom: 2) trigger from stimulus or from past stuttering
Tom: but if 1) than 2) is also happening.
Tom: that's why we can easily speak fluently because we control 2)
Tom: if it were as Per says, neuro each time how come we can have magic fluency spells?
Per: the "magic fluency spells are interesting"
Per: I think there is a lot to say about that
Per: 1) Some speaking conditions, like choral speech and altered feedback may bypass the neurological issue
Per: 2) If this system in the brain is unstable, very small physiological, emotional and cognitive changes may result in very different output. Cytokines from the immune system may reduce brain activity and cause a bad day, hormones, tiredness, bad emotions, etc may do the same. Focused anger or happiness may do the opposite! Also in Parkinson's disease -- in PD the talk about "paradoxical movements" -- sometimes very impaired patients can move surprisingly well
Tom: Per I agree with both! :-)
Tom: but I am talking about just reading and re-reading and focusing and suddenly we can read fluently.
Tom: here is my view:
Tom: 1) we relax and are less prone to triggers.
Tom: 2) because one word was fluent, the prob for the next to be fluent is higher because triggers depend on the last word.
Tom: 3) we have no high demand.
Tom: one way to test this is to see whether prob of stuttering is correlated to last word stuttered.
Per: yes, that is interesting. Viscious and positive circles.
Tom: re 2) it is an escalating phenomena.
Tom: yes. it's a type of differential equation like a radioactive decay. df/dt= c* f
Tom: and once you have a strong jamming it flips in the other direction
Per: However, a study of Yairi found that the severity at onset had no influence at all at the chance of spontaneous recovery -- also cases with severe stuttering at onset recovered. This would not be expected with this equation?
Tom: i have an answer here too! :)
Tom: the equation is for moments of stuttering, short-term behaviour but not long-term behaviour.
Tom: it does explain why a small neuro gives learned behaviours alive or lets them go because a small change in constant c leads to very different behaviour.
Tom: recovery is a different story i will talk in antwerp about it.
Tom: so I say: Prob (Stuttering, t) relates to Prob(Stuttering, t-1)
Tom: now there are other influences.
Tom: The neuro can change: either a) trigger leading to changed brain state like fear b) general well-being which will change prob of jamming.
Per: OK, it is possible, but will be difficult to prove -- difficult to separate from other hidden factors?
Tom: yes difficult to prove but these things must exist really or at least some of them because they are general feature of the brain or of systems
Per: well, I guess they are likely -- but still nature sometimes surprise us!
Tom: that's a fitting last sentence! Thanks for the debate!
Per: Thanks! Have a good night!!


moose2079 said...

Tom - I have noted that people that stutter are able to speak outload alone in a room without blocking?
Why is this so?

Tom Weidig said...

Yes, when speaking along people stutter less, but not to all every time.

1) Talking to oneself is an easier processing task for the brain, because you do not need to think about what others will think about you and you are not under time pressure. You think before you speak.

2) You are under no or little general stress. Stress impacts any activity.

3) There are no triggers like situations or people present where you have stuttered before.

Because there are less demands the brain of people who stutter is able to cope with the speaking situation neurologically better AND because there is no feared situations no fear is triggered.

Anonymous said...

Hi Tom,

Yes, a very good debate between yourself and Per. But can I pls be honest? That's all it is - a debate. The average stutterer doesn't care about differential equations, and wants 'real-life' and practical tools and techniques that they can use in their daily lives to help cope with their stutter.
As a man of science myself, I've also often suffered from 'analysis-paralysis'. If a set of differential equations or a mathematical model can help 'cure' a stutter, then that would be every stutterers dream come true.
Maybe one day that will be possible. Until then, I feel the 'soft' skills learnt at conferences hit home far more than
numerical, obscure, scientific speculations.
All the best, and a great blog by the way.

Tom Weidig said...

Hi Anon,

the debate is about the theory of stuttering and not the application to therapy. so per definition it is not helpful directly.

but if we want to understand stuttering better, we need to take a step back and understand the big picture.

150 Years ago people were telling Faraday. Why the hell do you spend your time doing experiments with this strange electricity stuff! DO SOMETHING USEFUL! Learn about horses, farming, and so on!

If we only took your attitude, we would still be animals! ;-)

Best wishes,

Anonymous said...

Hey Anon -

Can I pls be honest?

I don't want any more techniques or practical tools for stopping or managing my stuttering.

In my experience, they're all bullshit. The crap is deep enough as it is.

Good luck on your journey to find more shit. I'm sure some expert will try to sell you some.

Anonymous said...

Tom, it looks like the Moose above has made some comments in the Stuttering Innovations entry below and is looking for a response.

Anonymous said...

It was very interesting for me to read the article. Thanx for it. I like such themes and anything connected to this matter. I would like to read a bit more soon.

Anonymous said...

Hi Tom,

"If we only took your attitude, we would still be animals! ;-)"

Wow....what an incredibly illogical response for a scientist.
Or even a non-scientist.

All I'm saying is that the conference workshops that you discredit in your blog are actually very useful to a lot of people. And they don't need to be about hard science. They can be about human behaviour, about pushing ourselves out of our comfort zones, about interview techniques, etc etc.
Ironically, you state " talk about weaknesses of own models or mistakes...." and do you do the same? When someone merely likes something that you do not, are you prepared to have a rational and
civil debate?
If you read my previous post, I state that I am from a scientiic background myself, and if I could use finite element methods, or Fourier anaylsis, or use second order deifferntial equations with constant co-efficients to help with my stuttering, then I'd be first to proclaim their usefulness.

Take care, and a great job with the blog.

Tom Weidig said...

Hi Anon,

please use a name. It is easier.

I am not saying that one can use mathematics to understand stuttering. I just used one equation to highlight a simple system where a small perturbation makes a big impact.

I am just saying that theoretical debates needs to be taken to classify our understanding.

We cannot only have workshops that are great in exchanging experiences, but they are not enough to get to a higher level of understanding.

Dave Rowley said...

Interesting debate. What it suggests very strongly to me is that we need more evidence, particularly regarding subtypes. On the question of 'magic fluency spells', this variation in the signs of a problem exists in many areas, see for example the debate on cognitive fluctuations in people with Alzheimer's disease or Lewy Body dementia, where the fluctuations are even more pronounced, and triggered by very small (by normal standards) changes in stress levels, tiredness, etc. So I'm not surprised by Per's view that "very small physiological, emotional and cognitive changes may result in very different output".

Tom Weidig said...

Hi Dave,

did Per voice this view?

I was the only one who said that small changes can lead to large differences?

Do you have an article on the fluctuations in Alzheimer's and Lewy Body?


Dave Rowley said...

Here's what I took to be Per's comments, in context:

Per: 2) If this system in the brain is unstable, very small physiological, emotional and cognitive changes may result in very different output. Cytokines from the immune system may reduce brain activity and cause a bad day, hormones, tiredness, bad emotions, etc may do the same. Focused anger or happiness may do the opposite! Also in Parkinson's disease -- in PD the talk about "paradoxical movements" -- sometimes very impaired patients can move surprisingly well
Tom: Per I agree with both! :-)

I'll try to dig out the article!

Dave Rowley said...

Here's the link:

Not Per Alm said...

Tom, are you trying to use Dr. Per Alm's name to give your blog legitmacy???

Because Per Alm is a serious researcher, and you attack good dedicated researchers like Dr. Mark Onslow.

There are those that hate/dislike you and those that don't like you.

Tell us who likes you? And also give us the list of people who think you are out of line, crazy, irrevalant, not good....

Okay, Roger Ingham is your friend, but who else?

Tom Weidig said...

To NotPerAlm,

I can see you are not a scientist, because you focus on people and social recognition and not the arguments.

Who cares if people like me or not? And if everyone hates me, that doesn't falsify my arguments.

Who cares if Onslow is a dedicated researcher? All that matters is whether the research is useful or the statistics done well!

Who cares if Ingham likes me or not? That doesn't make my arguments right!

It is about arguments, and no-one ever debates me. Are they scared?

But Per does and we had a good debate. That's what science is about.