Monday, January 13, 1997

Fear is not a fundamental cause of blocking

From: Winston Purdy
>So I agree with Richard H. that the blockage takes place in the brain as a
>result of a (very real) fear that the speech mechanism won't work

I don't want to put words in Richard's mouth, but, since so far I have agreed with everything Richard says, I assume we have the same mental "model". At any rate, according to "mine", yes, blocks occur "in the brain" but no, NOT NECESSARILY as a result of fear. Fear certainly contributes to whatever factors trigger blocks, but its absence is no guarantee of fluency. I say this from personal experience. I have long eliminated all concerns about stuttering on any words but an occasional block still manages to catch me by surprise. NONE is a result of any fear or "expectation" on my part.

Elimination of fear will invariably result in fluency improvement, and, for this reason, it's an essential element of any therapy, BUT, if we are looking for fundamental causes of stuttering, it's a red herring, IMO.

Wednesday, October 23, 1996

Computer models of the brain

> From: Darrell Dodge
> But there are neurological processes that could be hypothesized to play a
> part in situations like Vicki's.
> Enough. This hatchet-job would probably not impress my biopsych prof. And
> that's just one reason why I need to be hitting the books instead of
> continuing here.


It impressed me! It's great that you are able to even begin to think at this level of granularity. It's true that rats can't talk, but it's not completely unfeasible to turn some of these neurological ideas into computer models. Computers CAN speak. The way they have been programmed to do so, so far, has nothing to do with how we produce speech, but it wouldn't be impossible to build a speech producing mechanism based on the kind of control issues we are talking about.

My dream is to produce a speech producing apparatus with a little knob, such that, if I turn the knob a bit, stuttering starts happening. Now, if someone can give me some good arguments why NASA should be funding this type of work...

Some time ago Megan Neilson sent me some very interesting papers on the work she and colleagues were doing at the Univ. of New South Wales. They built a mathematical model (Adaptive Model Theory) according to which a problem in auditory tracking could be responsible for stuttering. The point I want to make is not whether or not their model is valid for this purpose (I've been hoping to get the time to study it carefully...), but that it is in fact possible to start building such models! If Megan is still listening she might give us an update on her work...

Anyhow, Darrell, keep up your model thinking... even though it's sure to be above many of our heads... especially mine.

Thursday, October 17, 1996

Onset and ending of "Sudden Fluency"

Victoria Benson reported on her own experience of "sudden fluency" for a period of about two months after an accident (brain stem injury). Then the stuttering returned.


How did people "explain" to you this occurrence (sudden fluency)? It goes completely against all "learning" models. It is as if someone were to suddenly start speaking French...

From a neurological point of view, however, this can be explained as a very organic effect, such as a chemical produced as a result of the injury and recovery process, which happened to offset whatever causes our neurological problem. As the recovery process ended, the original "set point" took over.

Unfortunately this is a kind of experiment I WOULDN'T want to take part in...
Glad you made it back stuttering and all!

Wednesday, October 16, 1996

More on the radical neurological position

Marty Jezer stated that "the core neurological problem is not a singular problem. There is no one stuttering circuit that governs stuttering/fluency (just as there is no one gene that causes stuttering"


You could be right, but does it hurt to think of one core cause for a start? Let's look for the most likely ONE... and if doesn't do the trick let's look for more (..Occam's razor). The issue of speech circuits and genetics are related, but different. Genes are simply "switches" that set a whole development process in motion. In this context I would also bet against a "single gene" for stuttering. But suppose the problem is simply caused by low levels of some chemical whose production is dictated by a
particular gene... It may be unlikely, but not entirely implausible.

I don't think nature would create a "circuit" for stuttering, but, given a well developed and honed circuit for speech, there could be a particular weak link, such that, if anything is going to break, that's the link that's going to break. As part of my job, we flew one of the early Apple Powerbooks on the Shuttle. With all its complex circuitry, there was one fuse that had a tendency to blow up for no apparent reason. We were lucky - it didn't break - but we were sweating it (BTW, no danger to people.. only to an experiment!)

Mary continues:
> Speech, being as complex as it is, is subject to
> many areas of vulnerability, and many different singular and
> interactive neurological glitches.

Again, we really don't know. Some symptoms (sneezing, for example) can have multiple different causes (dust, allergies, colds etc.) and some have a clear specific cause. Complexity, in and of itself, doesn't imply several equiprobable failure modes. The heart keeps on going and going. The most common serious mishap is a heart attack ... and then the symptoms are clear. You could be right, but let's not use the "multiple glitches" possibility as an excuse to throw our hands up in desperation. Give me "one" glitch ... and the others will follow..

Marty also stated that drug research isn't really looking for a "fluency pill", rather for a pill that might lessen brain excitation and thus "affect the threshold of motor malfunction"

Some drugs can cure causes, some can cover symptoms. If the latter is the
best we can do, I'll take it!

Woody Starkweather stated his objection to the "radical neurologial" position on the grounds that, once the onion is peeled (using my metaphor), there is virtually no problem left.. just some "behavioral residue" so small that it is not likely to be the result of some neurological flaw.

You stated the objection and then you actually answered it. I've personally been stuck with this possible "behavioral residue" for a long time. The reason why I remain somewhat active in the stuttering community is no longer the need to find a cure for myself. Stuttering has stopped being an issue for me. I just feel that this "behavioral residue" is the KEY to the problem. From a therapist's point of view, the problem has practically vanished. I think that this is the point where one can finally start addressing and studying the real problem (from a researcher's point of view). The point is not that we need to push the "cure" further (although I wouldn't mind) but that understanding the core problem could prevent in the future the accumulation of all the upper layers.

Another "perverse" reason why there isn't much left after peeling away at the layers *could be* that the layers allowed themselves to be peeled away only because the core cause abated. Just like most children become fluent after "stuttering" periods, possibly aging, in some adults, also affects a "cure". I have mentioned this several times and I am surprised that this possibility hasn't been looked into (that I know... do set me straight). Let's study "recovered" stutterers!

Let me also mention that I must concede that between your emphasis on early intervention and "core neurology" there may be only a semantic difference. As we have discussed in the past, it is often impossible to differentiate soft from hard circuitry in the brain.. and when one turns into the other, and if and what effects the early environment has on this process. If presumably the core problem is "structural" I have no strong arguments for stating that this faulty structure had to be present at birth as opposed to say after 2 or 3 years of childhood development.

Do we start with a only very vague predisposition whose "hardening" could almost always be avoided (with the right care), or do we start with a predisposition whose hardening is usually inevitable? From fetus to the first few years we must understand what we can do and when. I consider your work well within these very important parameters.

Thank you!!! (And thanks also to all the therapist who work at the "upper layers" to relieve so much pain and to help make us functional..)

Sorry about this long post, but everybody had been making such good
points that I couldn't resist packaging it all together.

Tuesday, October 15, 1996

Issues with a "single theory" of stuttering

Andrew Carpenter comments that no single stuttering theory could cover all the levels indicated by the "onion" metaphor, so searching for such "single theory" is "misguided"


I agree... but the HOPE really is that if the core phenomenon could be
addressed directly BEFORE the developmental aspects take hold, then further
"upper layer" theories, while interesting for an understanding of learning,
would be unnecessary for "curing" stuttering.

He comments further that while there are good reasons to pursue neurological research, there is a danger of unneeded "radicalization".

Given the forces at play (the whole theapeutic community -understandably-
deals with the upper layers), I doubt very much that we run the risk of
becoming too radicalized in the neurological direction.

Thursday, October 10, 1996

Biological "set points"

In answer to a statement I made earlier:

> >The more "radical" neurological position holds that there is such a "core".
> >and that, if we could get to it directly (say by some surgical or
> >drug procedure) the whole "onion" would *probably* just collapse and melt
>> away.

Andrew Carpenter commented:

> As you say, at this point this is speculation, but it does seem
> implausible to me. Even if we were able to take a "fluency pill" or have a
> fluency operation, or whatever, there would still be all the emotional,
> attitudunal, and socialization problems to deal with. Although I could
> understand secondary behaviors melting away, this other stuff would still
> have to be dealt with.


I'm SO happy you keyed in on this, because this is precisely the notion, however speculative, that some of us want to bring to the fore.

Most biological systems have "set points" of stability. The speech system is no exception. Start with a neurological problem and you build all kinds of coping mechanism to be able to communicate. In combination, original problem and coping mechanisms establish a stuttering "set point". This point is VERY stable, as many of us would attest. SLPs do a valiant job at looking at the mushy multifaceted result. They will help chip away at some of the (bad) coping mechanisms, and push the set point towards fluency, but the tendency (as many will attest) is to get right back to
the stuttering set point. This is not surprising according to this model.


If you could simply "remove" the original neurological problem, my believe is that even well entrenched bad habits, such as looking ahead for feared words, struggling etc. would just "melt away". Would it take weeks, months, years? I don't have a strong feel for the answer, but I know that at this point the natural set point would be "fluency", and it would be more difficult for the body to stay away from it than to fall back into it.

A good analogy is obesity. A therapist can look at a 300 lb person and find all kinds of reasons why this person is eating too much. With much struggle this person can be helped, but the "natural" tendency is to fall right back to the 300 lb set point. If you could change the set point to 160 lb, all those seemingly insurmountable psychological problems and bad eating habits would vanish of their own accord.

Speculative? Yes. Implausible? No. And, as Richard H. often points out, the consequences of defining stuttering in terms of its final manifestation (multi-"causal", multi-faceted etc.) has a profound influence in how it is dealt with by the medical community, insurance companies and by researchers. Yes, (to state the radical neurological belief) there is a SINGLE core cause, and, we'll find it...

Wednesday, October 09, 1996

The radical neurological view

Andrew Carpenter said: "stuttering is a complex, developmental disorder that is going to have several significant causes, one of which certainly may be a neurological predisposition.

And here is precisely where the difference lies. Everyone will agree that, at the point where "full blown stuttering" has become entrenched, it has BECOME a multi-faceted problem, requiring intervention in different areas (my "peeling the onion" metaphor), because that's the only way to get to the "core".

The more "radical" neurological position holds that there is such a "core", and that, if we could get to it directly (say by some surgical or drug procedure) the whole "onion" would *probably* just collapse and melt away.