Wednesday, October 19, 2005

Joe on 2 loop

Here is a interesting comment from Joe D.:

There is the 2 loop theory of stuttering which comes close to your own theory. Riley et al. (1997) discussed the medial or inner loop system which may be “abnormal “ in PWS. The authors suggest that this inner loop is concerned with spontaneous speech and is regulated by the striatum (part of the basla ganglia involved in the planning of movement and of other processes of executive function).

The more “active” the striatum, the more fluent the speaker. However, increased dopamine in the striatum will cause hypometabolism (less activity) and prevent it from working efficiently. This is the basic assumption of the dopamine theories of stuttering.

Riley and McGuire’s work states that the striatum can be avoided all together by using the outer loop. The outer loop is “activated” by using fluency shaping techniques, sticking a device in your ear, chorale reading or basically anything different from the typical speech process.

This theory fits in nicely with the new theories on drugs and stuttering. Basically, if you reduce the levels of Dopamine in the striatum pharmacologically , then it will work more efficiently. joe D.

Yes, I am aware of their work, vaguely. Actually Per Alm mentions them in his article and PhD thesis. It makes a lot of sense, and gives flexibility to accomodate of the idiosyncracies of PDS. However, I am still unsure how this fits with structural and functional differences in PDS brains. But certainly, we are moving into an area where theories (like this one) can be tested in experiments.

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