ISCA Workshop on Plasticity in Speech Perception (PSP2005)

Senate House, London, UK
June 15-17, 2005

Plasticity in Recovery and Persistence of Stuttering

Peter Howell (1), Stephen Davis (1), Kate Watkins (2), Katharina Dworzynski (3), Ceri Savage (3)

(1) University College London; (2) University of Oxford; (3) Institute of Psychiatry, UK

Recovery from a speech disorder may indicate that correction can be made to the neural control systems that subserve speech production. Conversely, people who persist in this same speech disorder may lack such plasticity. In this submission we report on longitudinal work with a group of individuals all of whom stuttered in childhood. It is known which of these individuals, now aged 18 and over, have persisted in the disorder and which have recovered. This has allowed us to investigate what factors led speakers who persist in their stutter to be less 'plastic' than those who recover. We report results addressing whether speakers who persist in their stutter (SPS) show different types of disfluency in their speech to speakers who recover from their stutter (SRS) at the onset of the disorder. There appear to be no difference between SPS and SRS near onset of the disorder. We also report results addressing whether SPS differ in type of disfluency form SRS in adulthood. Here there are differences between the speaker groups (the SPS show a disproportionate number of part word disfluencies on content words). Data on the family background of stuttering in the two groups showed similar patterns, suggesting that persistent stuttering is a functional rather than a biological disorder. At the time of writing this abstract, we have completed structural and functional scanning studies on these two groups of speakers. The results are not available at present but these were also designed to test whether there is a biological problem that leads to stuttering persisting in some speakers. The earlier family history data suggest that there will be no biostructural differences between the two speaker groups. Thus, it would appear that one of the groups of speakers who stutter in early life have behavioral plasticity. Results are discussed that examine whether it is the SRS who change (a plastic process of recovery) or the SPS (a maladaptive plastic process these speakers adopt).

Full Paper

Bibliographic reference.  Howell, Peter / Davis, Stephen / Watkins, Kate / Dworzynski, Katharina / Savage, Ceri (2005): "Plasticity in recovery and persistence of stuttering", In PSP2005, 174-177.