paul brocklehurst, martin corley, & robin lickley february 2011

The influence of anticipation of communication failure on the likelihood

of stuttering

Does being misunderstood precipitate stuttering?

Paul Brocklehurst, Martin Corley, & Robin Lickley February 2011

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).

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)

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

When does stuttering occur?

Stuttering also occurs...

• When speaking one’s name

• When providing simple one-word answers

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)

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)

.

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?

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?

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

• 12 Participants who stutter

• speak single-syllable words into speech-recognition software*

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.

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)

Experiment 1

plod prod pod odd mod

Cue:

– Push with a finger or stick

Do you think you may stammer on this word?

no maybe yes

Did you stammer?

no maybe yes

Cue:

– Push with a finger or stick

– wrong!

you said plod

0% correct so far

plod prod pod odd mod

Cue:

– Push with a finger or stick

– correct!

you said prod

25% correct so far

plod prod pod odd mod

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!)

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

2 experimental conditionsFeedback: “correct!” 16 words x 4 iterationsFeedback: “wrong!” * 16 words x 4 iterations

FillersFeedback: “correct!” 16 words x 4 iterations

* fourth iteration is occasionally correct.

Experiment 1

wick fan prod shrink mat

Cue:

– Push with a finger or stick

Do you think you may stammer on this word?

no maybe yes

our predictions

1 2 3 4Iteration

Stutt

erin

g lik

elih

ood

‘correct!’ visual feedback

‘wrong!’ visual feedback

Results

1. Self reports • PWS• Normally-fluent speakers(Experiment 2)

2. Naive, independent-rater reports • PWS• Normally-fluent speakers (Experiment 2)

• Logistic (mixed effects) regression analyses (with likelihood of stuttering as the outcome variable)

no Maybe yes0%

20%

40%

60%

80%

100%

% fluent% stuttered

PWS’ predictions (made prior to iteration 1 )

Stutt

erin

g –

self

repo

rts

(iter

ation

s 1-4

)Do you think you may stammer?

Outcomes following PWS’ predictions

Significant main effects of PWS’ prior predictions***

12 Participants who stutter48 different words, each repeated four times by each participant.

***

***

1 2 3 40

10

20

30

40

50

60

PWS self-reports of stuttering

CorrectIncorrectFillers (correct)

iteration number

stutt

erin

g - s

elf r

epor

ts

Iteration X condition interaction*

Condition Word recognized options cue

‘correct’ HEART art heart cart Bart art a vital organ

‘incorrect’ PLOD plod prod pod odd mod Push with a finger or stick

condition

1 2 3 40

10

20

30

40

50

60

EXPERIMENT 2 – Normally-fluent speakers self-reports of difficulty speaking fluently

Correct

Incorrect

Fillers (correct)

iteration number

fluen

cy-d

ifficu

lty -

self

repo

rts

Condition Word recognized options cue

‘correct’ HEART art heart cart Bart art a vital organ

‘incorrect’ PLOD plod prod pod odd mod Push with a finger or stick

condition

Codings by an independent rater

Coder... • was naive to the purpose and procedure of

the experiment.• has a family member who stutters.

Condition Word recognized options cue

‘correct’ HEART art heart cart Bart art a vital organ

‘incorrect’ PLOD plod prod pod odd mod Push with a finger or stick

1 2 3 40

5

10

15

20

25

30

35

PWS naive-coder reports of stuttering(including prolongations)

CorrectIncorrectFillers (correct)

iteration number

stutt

ers

condition

1 2 3 40

5

10

15

20

25

30

35

PWS naive-coder reports of(including prolongations)

CorrectIncorrectFillers (correct)

iteration number

stutt

ers

Iteration X condition interaction*

condition Word recognized options cue

‘correct’ HEART art heart cart Bart art a vital organ

‘incorrect’ PLOD plod prod pod odd mod Push with a finger or stick

condition

1 2 3 40

5

10

15

20

25

30

35

PWS naive-coder reports of stuttering(excluding prolongations)

CorrectIncorrectFillers (correct)

iteration number

stutt

ers

Main effect of condition *Marginal main effect of iteration p<.10No interaction

condition Word recognized options cue

‘correct’ HEART art heart cart Bart art a vital organ

‘incorrect’ PLOD plod prod pod odd mod Push with a finger or stick

condition

1 2 3 40

5

10

15

20

25

30

35

Normally-fluent speakers naive-coder reports of stuttering

(including prolongations)

CorrectIncorrectFillers (correct)

iteration number

stutt

ers

condition Word recognized options cue

‘correct’ HEART art heart cart Bart art a vital organ

‘incorrect’ PLOD plod prod pod odd mod Push with a finger or stick

condition

condition Word recognized options cue

‘correct’ HEART art heart cart Bart art a vital organ

‘incorrect’ PLOD plod prod pod odd mod Push with a finger or stick

condition

1 2 3 40

5

10

15

20

25

30

35

Normally-fluent speakers naive-coder reports of stuttering

(excluding prolongations)

CorrectIncorrectFillers (correct)

iteration number

stutt

ers

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’

Summary – naive rater reportsFor 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.

Conclusions

• PWS stutter more when they think their words are not being

recognised

• Normally-fluent speakers do not show the same pattern

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.

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

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

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.

The Edinburgh Disfluency Group http://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

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”

1 2 3 40

10

20

30

40

50

60

PWS self-reports of stuttering across 4 iterations and 2 feedback conditions

Correct

Incorrect

Fillers (correct)

iteration number

stutt

erin

g - s

elf r

epor

ts

Condition Word recognized options cue

‘correct’ HEART art heart cart Bart art a vital organ

‘incorrect’ PLOD plod prod pod odd mod Push with a finger or stick

Fillers GRAVE wick fan grave shrink mat Where someone is buried

condition

ReferencesAndrews, 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.

ReferencesJohnson, 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, orofacial nonspeech, 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.