Commenter Ora was kind enough to make a thoughtful response to my last post on why 'neurogenic' and 'developmental' stuttering are not are not good complementary names for the two related conditions. This raises a classic blogging issue - with no editor to pre-read and review copy, a writer can never be sure that the intended message is getting through. I know what I think, and I know what I want to say, but I can't know that I'm writing well enough to make my point.
My previous post on the use of the term 'neurogenic' was intended to be short, as a respite to my usual long-winded (blog-wise) entries. Let me take the opportunity to elaborate on the important reasons why I think it's worth making the neurogenic distinction.
First, regardless of the importance of learned behavior in the confirmed developmental stutterer, the condition of developmental stutter either is or is not of neurogenic origin. I happen to believe that the evidence, both direct and indirect, is sufficiently strong to favor a neurogenic origin as a default assumption. If this is true, then the term neurogenic cannot logically be used to distinguish the developmental and acquired versions of the condition. Even if one is not fully convinced that developmental stutter is always neurogenic in origin, there is sufficient evidence pointing in that direction to make the developmental/neurological distinction a poor one for distinguishing the two types of stutter.
When a child starts to show signs of stuttering, an obvious question is 'why?' What is causing the disordering of the child's speech? For decades, many believed that children naturally spoke imperfectly, and gradually 'learned' to stutter. This was always an assertion, rather than a theory or even hypothesis, and it was wrong. The weight of evidence favors the belief that children start to stutter during their speech development process because they have a neurological deficit of some kind. Whatever happens later in life, the beginning stutterer has a neurological condition, and retains that condition as long as they stutter. That there are learned elements to chronic stuttering is certainly true. However, if one were to strip away the learned behaviors (eye blinks, head jerks, forced articulation, improper breathing, etc) from the basic neurological element - the block - what would we be left with? My answer is: a stutterer. Thus, there is the (neurological) condition - stutter - and there are the behavioral and affective responses. Should a condition be defined by its fundamental nature, or by the response to it?
A particular (and practical) motivation for my emphasis on the neurological basis of developmental stutter is the support such an understanding could give to stutterers themselves. For any stutterer, the knowledge that their condition has a specific, organic source rather than just 'something that happens' could be a comfort when dealing with it. Based on Internet stutter groups, many stutterers don't have the slightest knowledge of the condition, and old wives tales are as common as science among the afflicted. When you have people insisting that 'you can catch it,' we shouldn't be surprised that so many stutterers have difficulty dealing with the condition.
A specific case for the value of defining developmental stutter as neurogenic would be in cases of therapeutic relapse. Stutterers who go through stutter-suppressing therapy like fluency shaping can find that a relapse leaves them worse than when they started therapy. This can induce guilt and depression over the lost 'fluency. If one started with the understanding that developmental stutter has a neurogenic basis, it would be easier to accept the possibility of relapse. Under the neurogenic assumption, stutter therapy is an attempt to 'fight city hall.' If we are trying to fight the wiring of our brains, rather than 'bad behavior,' then we can understand why it should be so difficult to eliminate stutter blocks entirely.
A stutterer grounded by an understanding of the neurogenic basis of the condition should be less likely to experience such high highs (assuming their stuttering is 'cured'), and low lows (crashing and burning after relapse).
To commenter Ora's point about therapy: by it's nature, all stutter therapy must be behavioral. Drugs have been tried, and found wanting. We can't get at the brain, so we can only make conscious efforts to modify speech. I don't think there's any fear of taking away from this necessity by stressing the neurological basis of the condition. Until there is some fundamental breakthrough in treatment, stutter therapy can only involve three elements; cognitive, affective and behavioral. That is, we can learn about the condition, we can learn about how the condition affects us emotionally, and we can learn to modify the actual speech process. My stress on the neurogenic basis of stutter is part of the cognitive element. Alone, it does nothing to change speech. It could, however, serve the therapeutic process by setting parameters. Stutter is not a behavioral bad habit, simply to be unlearned. The learning process of stutter therapy is a process of actively learning to deal with the neurological element - the block. To me, this is the critical issue of stutter therapy. The piano student must master the challenge of difficult finger movement and coordination. But for all the difficulty of mastering the piano, the piano does not fight back. The neurological abnormality that triggers the stutter block does. One doesn't practice a away stutter and become a normal speaker - at least very few do.
Although most stutter therapy doesn't actively raise the neurological issue, most deal with it implicitly. The fluency shaping approach doesn't explicitly rule out a neurological basis for stutter, but it does work on the assumption that either there is no such basis, or that it can be over-ridden through training. The stutter modification school of therapy isn't based on a neurological theory, but it provides pragmatic treatment as if it did. Both schools of therapy engage in behavioral therapy, but the two are very different in outlook and in practice. By insisting on bringing out in the open the biological nature of the condition, we implicitly demand that different schools of therapy justify themselves to the facts of the condition.