Title: The impact of wordend phonology and morphology on stuttering
1The impact of word-end phonology and morphology
on stuttering
- Chloe Marshall
- Centre for Developmental Language Disorders and
Cognitive Neuroscience, - Department of Human Communication Science,
- University College London
- UCL, 27th June, 2005
2Acknowledgements
- Peter Howell and Jenny Hayes
- Heather van der Lely and John Harris
3Aims of todays talk
- Are stuttering rates in English-speaking adults
and children influenced by morphological and
phonological complexity at the ends of words? - Study 1 adult corpus data (UCLASS database)
- Study 2 non-word repetition task
- Study 3 elicitation task (inflected forms)
4Background 1
- Definition of phonological complexity
- Based on what typically developing children find
hard to acquire - e.g. late-acquired consonants (dorsals,
fricatives, liquids) - e.g. multisyllabic forms
- e.g. consonant clusters
- Definition of morphological complexity
- inflected forms e.g. runs, walked, singing
- derived forms e.g. unreal, happier, sunny
5 Background 2
- Why should we expect phonological and
morphological complexity to affect stuttering? - Evidence that consonant clusters influence
stuttering rates - Howell, Au-Yeung Sackin (2000)
- Word-initially, adults
- Weiss Jakielski (2003)
- Children 60 115
6 Background 3
- English inflection (-ed, -s) adds a consonant,
and therefore increases the phonological
complexity of the word, often forming a cluster. - e.g. wrap wrapped
- e.g. drive drives
- Confound between morphological and phonological
complexity. - How can they be teased apart?
7Study 1 adult corpus data (UCLASS database)
- Contrasts 4 sets of words
phonological complexity
4
3
morphological complexity
2
1
1 phon simple, morph simple bad 2 phon
simple, morph complex died 3 phon complex,
morph simple month 4 phon complex, morph
complex looked
8What we might find (1)
Phonological complexity influences stuttering
independently of morphology
9What we might find (2)
Morphological complexity influences stuttering
independently of phonology
10What we might find (3)
Interaction between phonological complexity and
morphological complexity
11 Details of study participants
- 16 males, diagnosed as PWS
- 16 47 years, mean age 25, sd 9
- Spontaneous material in response to questions
from an interviewer, casual speech - words stuttered for each speaker 2.61 - 20.33
12Details of study words
Phonology word-shape is CVC or CVCC
Morphology past tense -ed, plural -s, third
person -s
13Details of study selecting words from corpus
- Perl program identified words of shape CVC and
CVCC - Words hand-coded as being morphologically complex
or not - Irregular verbs removed by hand (e.g. had, got,
has) - Each word classified as stuttered (1) or not
stuttered (0), based on such events marked in
original transcriptions
14Results 1
15Results 2
16Conclusions
- Presence of a cluster at the end of a word does
not influence stuttering rates in spontaneous
speech - Nor is there an effect of inflectional morphology
- However data not amenable to individual
analysis - For certain speakers either type of complexity
might have an effect
17 Study 2 Non-word repetition task
- Aim to investigate whether the presence of a
consonant cluster at the word-end influences
stuttering rates in absence of morphological
complexity - Advantage over spontaneous studies can elicit
enough tokens of interest from all participants,
therefore data amenable to individual analysis
18 Details of study participants
- 19 speakers
- Average age 14 years
- Divided into 2 groups
- Group 1 lt or 14 years (N12)
- Group 2 or gt 15 years (N7)
19 Details of study stimuli(Test of
Phonological Structure, van der Lely Harris,
1999)
- 2 experimental conditions
- No word-final cluster ket, prif (N 8)
- Word-final cluster kest, prilf (N 8)
- 1 filler condition
- Multisyllabic deppary, sapiffy (N 12)
- Responses scored according to presence (1) or
absence (0) of stuttering
20Results
21Conclusion
- No impact of word-end phonological complexity
detected in this task
22Study 3 Elicitation task (inflected forms)
- Task designed to elicit 3rd person singular and
past tense forms - Aim to investigate whether the presence of a
consonant cluster at the word-end influences
stuttering rates in morphologically complex words
23 Details of study participants
- 19 speakers
- Average age 14 years
- Divided into 2 groups
- Group 1 lt or 14 years (N12)
- Group 2 or gt 15 years (N7)
24Details of study stimuli
- 2 conditions, varying phonological complexity
- Condition 1 5 verbs whose inflected word-shape
is CVC, e.g. weighs, weighed - Condition 2 5 verbs whose inflected word-shape
is CVCC, e.g. wraps, wrapped
25Details of study procedure
- Experimenter
- Everyday I pour a drink.
- Participant
- Your friend also ________ .
- Yesterday you both __________ .
26Results
27Individual results
28Conclusion
- A few individuals stutter on morphologically
complex forms - Only Participant 2 showed an effect of
phonological complexity on stuttering
29Discussion
- Some experimental evidence that phonological and
morphological complexity influence stuttering in
English PWS, but not for all speakers. - Still to look at
- Syllabic suffixes (wanted, horses, washes)
- Derivational morphology (heavier, unreal)
- Much younger children what happens at age 3?
30Reference
Marshall, C.R. (2005) The impact of word-end
phonology and morphology on stuttering.
Stammering Research, 1 375-391 http//www.stamres
.psychol.ucl.ac.uk/ My web page
www.ucl.ac.uk/DLDCN