Possible mechanisms behind the production of stammered dysfluencies.

- The Variable Release Threshold (VRT) Hypothesis

The approach to stammering therapy that we have developed, and which forms the basis of our online course, is based upon two theoretical tenets…

1. That the speech of people who stammer is (or was) somewhat error-prone

2. And that stammering occurs as a side-effect of stammerers’ attempts to avoid speech errors.

The VRT hypothesis provides a plausible, detailed explanation for why trying to avoid speech errors results in the production of stammered disfluencies. In the following slideshow, I have tried to explain the main points of the hypothesis in language that is, as far as possible, non-technical and easy to understand.

A more detailed exposition of the VRT hypothesis, and its grounding within the broader theoretical framework of anticipatory struggle hypotheses, is available in the Journal of Communication Disorders  publication: Brocklehurst Lickley & Corley (2013) Revisiting Bloodstein’s Anticipatory Struggle Hypothesis from a psycholinguistic perspective: A variable release threshold hypothesis of stuttering A free pre-print version of which is available here

If you would like to read yet more about the Variable Release Threshold hypothesis , here is an abridged version of Chapter 31 of the book “The Perfect Stutter” in which I explain in more detail how the threshold mechanism works and and how it is likely to develop in early childhood.

Having worked through this slideshow, when you next find yourself in a situation where you are likely to stammer, try to observe the sequence of feelings and your responses to those feelings that occur while you are about to start speaking.

In particular, observe how before you start to speak, there is often a feeling of doubt or uncertainty about whether or not you will be able to say an upcoming word or phrase in the way you want. This feeling is essentially a sort of anticipation. Sometimes it might involve a very specific anticipation of stammering. But often it might be a more general anticipation that the words will not come out in the way you want them to, or that the person you are speaking to will not understand you properly, or will not respond to your words in the way you want them to.

Observe exactly what happens when you actually block. In particular, try to distinguish between the experience of blocking and your response to the block.

· Essentially, the block is like a temporary paralysis of your speech muscles… As a result of this temporary paralysis, the word simply doesn’t come out when it should. This is completely outside of your immediate conscious control.

· This experience (of temporary paralysis of your speech muscles) results when you try to say a syllable or word which is not sufficiently activated. In other words, when its activation level is still below the ‘release threshold’.

Then observe how you respond to the block. Stammerers respond to blocks and to the anticipatory feelings that precede them in a wide variety of different ways. Their responses, and the ramifications of these responses were described in detail in our YouTube videos entitled “The secondary symptoms of stammering” on the previous webpage.

The primary purpose of this online course is to teach you how to reduce your tendency to block by ensuring that the words you try to say have a level of activation that is above the release threshold. The two techniques that we teach (Orchestral Speech and The Jump) both help to bring the release threshold down. In the slideshow entitled The theory behind Orchestral Speech and the Jump on the next webpage, we explain how they can achieve this.