Paul Brocklehurst, Martin Corley, & Robin Lickley February 2011

1. The influence of anticipation of communication failure on the likelihood of stutteringDoes being misunderstood precipitate stuttering? Paul Brocklehurst, Martin Corley, & Robin Lickley February 2011

2. What causes stuttering? • Genetic predisposition • Environmental factors • Concordance • 70% for monozygotic twins • 30% for dizygotic twins • (Andrews et al. 1983; Felsenfeld et al., 2000) • 18% for siblings of the same sex • (Andrews et al., 1983).

3. What causes stuttering? • Genetic predisposition • Environmental factors Stuttering often co-occurs with mild language or speech production impairment • Slow language formulation evidence from priming studies (e.g. Conture et al. 2004) • Imprecise articulation cinematic evidence (e.g. Max Caruso, & Gracco, 2003) • Error prone production evidence from tonguetwisters – (e.g. Brocklehurst & Corley, in press)

4. When does stuttering occur? Capacities and demands model • stuttering occurs at times of high cognitive / linguistic demands. (e.g. Andrews et al., 1983; Starkweather, 1987) ...but this is probably not the complete story

5. When does stuttering occur? Stuttering also occurs... • When speaking one’s name • When providing simple one-word answers

6. When does stuttering occur? Stuttering also occurs... • When speaking one’s name • When providing simple one-word answers • Single word utterances are easy to produce, but often relatively difficult for the listener to decode (due to the relative lack of redundancy)

7. The role of anticipation Anticipatory struggle hypothesis • stuttering occurs when the speaker anticipates that the quality of his speech may not be adequate to successfully fulfil its intended purpose. Anticipation of stuttering (Johnson, 1942, 1959) Anticipation of negative listener responses (Bloodstein 1958) Anticipation of general difficulty speaking (Bloodstein 1975) .

8. The current study • examines the role of anticipation of communication failure in precipitating stuttering. • What happens when the listener appears to misunderstand - irrespective of how “well” the speaker speaks?

9. The current study • examines the role of anticipation of communication failure in precipitating stuttering. • What happens when the listener appears to misunderstand - irrespective of how “well” the speaker speaks? • What happens when the listener appears to understand correctly - irrespective of how “badly” the speaker speaks?

10. The current study • examines the role of anticipation of communication failure in precipitating stuttering. • What happens when the listener appears to misunderstand - irrespective of how “well” the speaker speaks? • What happens when the listener appears to understand correctly - irrespective of how “badly” the speaker speaks? • 2 experiments... PWS and normally-fluent speakers

11. Experiment 1 • 12 Participants who stutter • speak single-syllable words into speech-recognition software*

12. Experiment 1 • 12 Participants who stutter • speak single-syllable words into speech-recognition software* • they repeat each word four times (consecutively) • visual feedback provided by speech-recognition software after each iteration.

13. Experiment 1 Participants provide (before and after) self-ratings... • “do you think you will stutter on this word?” • “did you stutter on this word” Iterations also recorded and rated by an independent coder (naive to the procedure)

14. plod prod pod odd mod Cue: • Push with a finger or stick Do you think you may stammer on this word? no maybe yes

16. Did you stammer? no maybe yes

17. plod prod pod odd mod Cue: • Push with a finger or stick • wrong! you said plod 0% correct so far

18. plod prod pod odd mod Cue: • Push with a finger or stick • correct! you said prod 25% correct so far

19. The current experiment Irrespective of participants’ actual performance, the software always... • recognizes 72% of the words correctly • Gets 28% of the words wrong (They don’t know this!)

20. The current experiment Irrespective of participants’ actual performance, the software always... • recognizes 72% of the words correctly • Gets 28% of the words wrong • £5 cash prize • if participant can score over 71% correct

21. Experiment 1 2 experimental conditions Feedback: “correct!” 16 words x 4 iterations Feedback: “wrong!” * 16 words x 4 iterations Fillers Feedback: “correct!” 16 words x 4 iterations * fourth iteration is occasionally correct.

22. wick fan prod shrink mat Cue: • Push with a finger or stick Do you think you may stammer on this word? no maybe yes

23. Stuttering likelihood 1 2 3 4 Iteration our predictions • ‘correct!’ visual feedback • ‘wrong!’ visual feedback

24. Results • Self reports • PWS • Normally-fluent speakers(Experiment 2) • Naive, independent-rater reports • PWS • Normally-fluent speakers (Experiment 2) • Logistic (mixed effects) regression analyses (with likelihood of stuttering as the outcome variable)

25. Do you think you may stammer?Outcomes following PWS’ predictions *** *** • Significant main effects of PWS’ prior predictions*** 12 Participants who stutter 48 different words, each repeated four times by each participant.

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28. Codings by an independent rater Coder... • was naive to the purpose and procedure of the experiment. • has a family member who stutters.

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34. Summary – self-reports (PWS) For PWS, the likelihood of self-reporting having stuttered on a word... • increased when, prior to the first iteration, the speaker anticipated that he would stutter. • decreased across iterations when the feedback was ‘correct’ but not when it was ‘incorrect’

35. Summary – naive rater reports For both PWS and normally-fluent speakers, the likelihood of being rated as having stuttered on a word... • increased across iterations. • (main effect – mainly due to prolongations) • increased across iterations even more when the feedback is incorrect.

36. Conclusions • PWS stutter more when they think their words are not being recognised • Normally-fluent speakers do not show the same pattern

37. Conclusions • Speakers attempt to make words easier to recognise by purposefully prolonging and/or emphasising key phonemes. • Even in normally-fluent speakers, attempts to render words easier to recognise may be interpreted by a (naive) listener as stuttering.

38. Conclusions • Findings suggest stuttering is reinforced by repeated experiences of failure to make oneself understood. • In real life there could be many reasons for experiencing such failure... • Impaired speech production • Impaired listener comprehension • Misleading feedback/cues from listener • a combination of the above

39. Further thoughts • The results are consistent with the Vicious Circle Hypothesis (Vasić & Wijnen, 2005) • Perhaps feedback suggesting listener miscomprehension... • Increases the vigilance of self-monitoring • Decreases the threshold for initiation of error repair • It may also influence the focus of monitoring • More focus on words with similar neighbours

40. Further thoughts • The results are consistent with a (modified) EXPLAN Hypothesis (Howell, 2003) • Perhaps feedback suggesting listener miscomprehension... • Leads to an increased articulatory-buffer release threshold • (excessively) delaying onset of speech.

41. The Edinburgh Disfluency Grouphttp://edgwiki.wikidot.com Researching disfluency from a psycholinguistic perspective: • Language and speech encoding • Grammar • Phonology • Phonetics • A general interest in • Speech errors • Speech-error repair and avoidance mechanisms

42. The role of anticipation Anticipatory struggle hypothesis (Bloodstein 1958)... • In the last analysis, neither excessive demands for fluency nor the occurrence of many repetitions in the child’s speech are absolutely necessary in order for struggle reactions to develop. The essential condition for stuttering is simply the child’s belief that communication is an arduous process and that he must put his back into it. (p31) • Stuttering characterised by “tension and fragmentation”

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44. References Andrews, G., Hoddinott, S., Craig, A., Howie, P., Feyer, A.-M., & Neilson, M. (1983). Stuttering: A Review of Research Findings and Theories circa 1982. J Speech Hear Disord, 48(3), 226-246. Bloodstein, O. (1958). Stuttering as an anticipatory struggle reaction. In J. Eisenson (Ed.), Stuttering: A symposium (pp. 3-69). New York: Harper & Row. Bloodstein, O. (1975). Stuttering as tension and fragmentation. In J. Eisenson (Ed.), Stuttering: A second symposium (pp. 1-96). New York: Harper & Row. Brocklehurst, P. H., & Corley, M. Investigating the inner speech of people who stutter: Evidence for (and against) the Covert Repair Hypothesis. [doi: DOI: 10.1016/j.jcomdis.2010.11.004]. Journal of Communication Disorders, In Press, Corrected Proof. Conture, E., Zackheim, C., Anderson, J., & Pellowski, M. (2004). Linguistic processes and childhood stuttering: many's a slip between intention and lip. In B. Maassen, R. Kent, H. Peters, P. v. Lieshout & W. Hulstijn (Eds.), Speech motor control in normal and disordered speech (pp. 253-281). Oxford: Oxford University Press. Felsenfeld, S., Kirk, K., Zhu, G., Statham, D., Neale, M., & Martin, N. (2000). A study of the genetic and environmental etiology of stuttering in a selected twin sample. Behavior Genetics, 30(5), 359-366. Howell, P. (2003). Is a perceptual monitor needed to explain how speech errors are repaired? Howell, P., & Au-Yeung, J. (2002). The EXPLAN theory of fluency control applied to the diagnosis of stuttering. Clinical linguistics: Theory and applications in speech pathology and therapy, 75–94.

45. References Johnson, W. (1942). A study of the onset and development of stuttering. Journal of Speech and Hearing Disorders, 7(3), 251. Johnson, W., & Associates, a. (1959). The onset of stuttering. Minneapolis MI: University of Minnesota press. Max, L., Caruso, A., & Gracco, V. (2003). Kinematic analyses of speech, orofacialnonspeech, and finger movements in stuttering and nonstuttering adults. Journal of Speech, Language, and Hearing Research, 46(1), 215. Postma, A., & Kolk, H. (1993). The covert repair hypothesis: prearticulatory repair processes in normal and stuttered disfluencies. J Speech Hear Res, 36(3), 472-487. Starkweather, C. (1987). Fluency and stuttering: Prentice-Hall, Inc. Vasić, N., & Wijnen, F. (2005). Stuttering as a monitoring deficit. In R. J. Hartsuiker, Y. Bastiaanse, A. Postma & F. Wijnen (Eds.), Phonological encoding and monitoring in normal and pathological speech (pp. 226–247). Hove, East Sussex Psychology Press.