a psycholinguistic perspective on child phonology sharon peperkamp emmanuel dupoux laboratoire de...
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A Psycholinguistic Perspective on Child Phonology
Sharon Peperkamp
Emmanuel Dupoux
Laboratoire de Sciences Cognitives et Psycholinguistique, EHESS-CNRS, Paris
www.lscp.net/persons/peperkamp
Second International Conference on Contrast in Phonology. Toronto, May 3-5, 2002
Child phonology
Jakobsonian view of phonological acquisition:
Children’s productions– reflect their internal grammar– evolve from universally unmarked structures towards
the marked structures present in their language
Outline of talk
• Discuss problems with child phonology
• Propose a model of phonological processing, featuring:– a distinction between perception and production– a distinction between phonology and phonetics
• Show how in this model:– acquisition can take place– data of child phonology can be accounted for
I. Child phonology
Problem #1: Initial state• Children’s earliest productions
unmarked structures:- consonant: [p]
- vowel: [a]
- syllable structure: CV
• Infants’ perceptual capacities between 0 and 2 months
marked structures- [pa] vs. [ba] (Eimas et al. 1971)
- [a] vs. [i] (Trehub 1973)
- V vs. CV vs. VC ?
Are initial representations really unmarked?
Problem #2: Preverbal acquisition
• 6 months vowels (Kuhl et al. 1992; Polka & Werker 1994)
• 9 months phonotactics(Friederici & Wessels 1993; Jusczyk et al. 1993,
1994)
• 10-12 months consonants (Werker & Tees 1984)
Experimental perception data:
Is grammatical knowledge really reflected in production?
Two time paths in acquisition
0 12 months 4 years
adult-like
adult-like
Perception
Production
universal:marked
universal:unmarked
Two time paths in acquisition
0 12 months 4 years
adult-like
adult-like
Perception
Production
Do children acquire one or two grammars?
universal:marked
universal:unmarked
Problem #3: Speed of acquisitionAcquisition of syllable structure (Fikkert 1994)
Elke age onsets rhymes
1;6.4 stops, nasals fricatives
1;6.25 glides stops
1;7.22 nasals
1;9.24 fricatives
1;11.28 liquids
2;0.11 stop+glide
2;3.27 stop+liquid
2;4.15 [s]+stop
Why does acquisition take so long?
Problem #4: Inter-individual variability
Production of 3-syllable tokens by twins(Savinainen-Makkonen 2000)
1;5 1;6 1;7
Annika 0% 100% 100%
Antti 0% 27% 37%
Why do children follow different time paths?
Problem #5: Gradual changesConsonant harmony by Trevor (Pater & Werle 2001)
Why is learning gradual?
Regressive velar harmony
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
~1;5 1;6 1;7 1;8 1;9 1;10 1;11 2;0 2;1 2;2 2;3 2;4
Age
Pro
port
ion h
arm
oniz
ed
Problem #6: Intra-individual variability
• type variabilityfrequent words resist correction (Storkel & Gierut 2001)
consonant harmony in French child language
Hélène, 4;8.7: très [k] ‘very’ - trou [tu] ‘hole’
Why is there a frequency effect?
• token variabilitynon-frequent words show free variation
consonant harmony in English child language
Trevor, 2:1.5: truck [trk] ~ [krk]
Why is there type-specific variability?
II. A theory of phonological acquisition
Perception Production
underlying form underlying form
Phonology
surface form surface form
Phonetics
universal phonetic motor planrepresentation
acoustic signal acoustic signal
phonological encoding
phonetic encoding
phonological decoding
phonetic decoding
Phonological processing
|thi|
[thi]
/ti/ /ti/
[thi]
|thi|
Initial statePerception Production
underlying form underlying form
Phonology
surface form surface form
Phonetics
universal phonetic motor planrepresentation
acoustic signal acoustic signal
phonological encoding:
phonological decoding:
phonetic decoding: identity
phonetic encoding:
Perception Production
underlying form underlying form
Phonology
surface form surface form
Phonetics
universal phonetic motor planrepresentation
acoustic signal acoustic signal
phonological encoding
phonetic encoding
phonological decoding
phonetic decoding
Step 1 Step 3
Step 2
Perception Production
underlying form underlying form
Phonology
surface form surface form
Phonetics
universal phonetic motor planrepresentation
acoustic signal acoustic signal
phonological encoding
phonetic encoding
phonological decoding
phonetic decoding
Step 1
Perception Production
underlying form underlying form
Phonology
surface form surface form
Phonetics
universal phonetic motor planrepresentation
acoustic signal acoustic signal
phonological encoding
phonetic encoding
phonological decoding
phonetic decoding
bottom-up algorithms- segments (Kuhl et al. 1997; Maye,
Werker & Gerken in press)
- syllable structure (Peperkamp 2001)
Perception Production
underlying form underlying form
Phonology
surface form surface form
Phonetics
universal phonetic motor planrepresentation
acoustic signal acoustic signal
phonological encoding
phonetic encoding
phonological decoding
phonetic decoding
0-12 months
Perception Production
underlying form underlying form
Phonology
surface form surface form
Phonetics
universal phonetic motor planrepresentation
acoustic signal acoustic signal
phonological encoding
phonetic encoding
phonological decoding
phonetic decoding
0-12 months
Step 2
Perception Production
underlying form underlying form
Phonology
surface form surface form
Phonetics
universal phonetic motor planrepresentation
acoustic signal acoustic signal
phonological encoding
phonetic encoding
phonological decoding
phonetic decoding
0-12 months
bottom-up algorithms - allophonic rules (Peperkamp & Dupoux 2002)
- neutralizing rules (Peperkamp & Dupoux 2002)
- stress (Dupoux & Peperkamp 2002)
Perception Production
underlying form underlying form
Phonology
surface form surface form
Phonetics
universal phonetic motor planrepresentation
acoustic signal acoustic signal
phonological encoding
phonetic encoding
phonological decoding
phonetic decoding
0-12 months
12 months - ??
Perception Production
underlying form underlying form
Phonology
surface form surface form
Phonetics
universal phonetic motor planrepresentation
acoustic signal acoustic signal
phonological encoding
phonetic encoding
phonological decoding
phonetic decoding
0-12 months Step 3
12 months - ??
Perception Production
underlying form underlying form
Phonology
surface form surface form
Phonetics
universal phonetic motor planrepresentation
acoustic signal acoustic signal
phonological encoding
phonetic encoding
phonological decoding
phonetic decoding
0-12 months
12 months - ??
trial and error algorithms(Boersma 1999)
Perception Production
underlying form underlying form
Phonology
surface form surface form
Phonetics
universal phonetic motor planrepresentation
acoustic signal acoustic signal
phonological encoding
phonetic encoding
phonological decoding
phonetic decoding
0-12 months 1-4 years
12 months - ??
surface form
motor plan
assembling rules retrieval from storage
Dual route for phonetic encoding
(Levelt 1989)
surface form
motor plan
Stage 1
[t, k] |k|
Creation of simplifying assembling rules
‘very’: [t] |k| assembled
‘hole’: [tu] |ku| assembled
surface form
motor plan
[t] |k|
Stage 2
[t, k] |k|
Storage of patterns
‘very’: [t] |k| assembled
‘hole’: [tu] |ku| assembled
surface form
motor plan
[t] |k|
Stage 2
[t, k] |k|
Storage of patterns
‘very’: [t] |k| retrieved from storage
‘hole’: [tu] |ku| assembled
surface form
motor plan
[t] |k|
Stage 3
[t, k] |t, k|
Correction of assembling rules
‘very’: [t] |k| retrieved from storage
‘hole’: [tu] |ku| assembled
surface form
motor plan
[t] |k|
Stage 3
[t, k] |t, k|
Correction of assembling rules
‘very’: [t] |k| retrieved from storage
‘hole’: [tu] |tu| assembled
surface form
motor plan
[t] |t|
Stage 4
[t, k] |t, k|
Correction of stored patterns
‘very’: [t] |k| retrieved from storage
‘hole’: [tu] |tu| assembled
surface form
motor plan
[t] |t|
Stage 4
[t, k] |t, k|
Correction of stored patterns
‘very’: [t] |t| retrieved from storage
‘hole’: [tu] |tu| assembled
Summary: phonetic encoding and children’s productions
Why does acquisition take so long?articulation is a complex motor skill
Why do children follow different time paths?the phonetic encoder is acquired by means of trial and error algorithms, which predict variation among individuals
Why is learning gradual?motor skills are learned with ups and downs
Why is there a frequency effect?during the acquisition of the phonetic encoder, the correction of stored patterns is more difficult for more frequent patterns
Why is there type-specific variability?there is competition both between and within the two routes, the outcome of which depends on both linguistic (e.g. utterance length) and extra-linguistic factors (e.g. fatigue)
Conclusion
• Models of phonological acquisition should take both perception and production data into account.
• Phenomena of ‘child phonology’ reflect the developing phonetic encoder.
• The phonetic encoder is partly non-linguistic; it should, therefore, be modeled within a psycholinguistic framework.