A Psycholinguistic Perspective on Child Phonology Sharon Peperkamp Emmanuel Dupoux Laboratoire de Sciences Cognitives et Psycholinguistique, EHESS-CNRS, Paris 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 monthsvowels (Kuhl et al. 1992; Polka & Werker 1994) 9 monthsphonotactics (Friederici & Wessels 1993; Jusczyk et al. 1993, 1994) monthsconsonants (Werker & Tees 1984) Experimental perception data: Is grammatical knowledge really reflected in production?
Two time paths in acquisition 012 months4 years adult-like Perception Production universal: marked universal: unmarked
Two time paths in acquisition 012 months4 years adult-like Perception Production Do children acquire one or two grammars? universal: marked universal: unmarked
Problem #3: Speed of acquisition Acquisition of syllable structure (Fikkert 1994) Elkeageonsetsrhymes 1;6.4stops, nasalsfricatives 1;6.25glidesstops 1;7.22nasals 1;9.24fricatives 1;11.28liquids 2;0.11stop+glide 2;3.27stop+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;51;61;7 Annika0%100%100% Antti0%27%37% Why do children follow different time paths?
Problem #5: Gradual changes Consonant harmony by Trevor (Pater & Werle 2001) Why is learning gradual?
Problem #6: Intra-individual variability type variability frequent words resist correction (Storkel & Gierut 2001) consonant harmony in French child language Hélène, 4;8.7: très [k ] ‘very’ - trou [t u] ‘hole’ Why is there a frequency effect? token variability non-frequent words show free variation consonant harmony in English child language Trevor, 2:1.5: truck [tr k] ~ [kr k] Why is there type-specific variability?
II. A theory of phonological acquisition
PerceptionProductionunderlying form Phonologysurface form Phonetics universal phoneticmotor plan representationacoustic signal phonological encoding phonetic encoding phonological decoding phonetic decoding Phonological processing |thi||thi| [t h i ] /ti/ [t h i ] |thi||thi|
Initial state PerceptionProductionunderlying form Phonologysurface form Phonetics universal phoneticmotor plan representationacoustic signal phonological encoding: phonological decoding: phonetic decoding: identity phonetic encoding:
PerceptionProductionunderlying form Phonologysurface form Phonetics universal phoneticmotor plan representationacoustic signal phonological encoding phonetic encoding phonological decoding phonetic decoding Step 1 Step 3 Step 2
PerceptionProductionunderlying form Phonologysurface form Phonetics universal phoneticmotor plan representationacoustic signal phonological encoding phonetic encoding phonological decoding phonetic decoding Step 1
PerceptionProductionunderlying form Phonologysurface form Phonetics universal phoneticmotor plan representationacoustic 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)
PerceptionProductionunderlying form Phonologysurface form Phonetics universal phoneticmotor plan representationacoustic signal phonological encoding phonetic encoding phonological decoding phonetic decoding 0-12 months
PerceptionProductionunderlying form Phonologysurface form Phonetics universal phoneticmotor plan representationacoustic signal phonological encoding phonetic encoding phonological decoding phonetic decoding 0-12 months Step 2
PerceptionProductionunderlying form Phonologysurface form Phonetics universal phoneticmotor plan representationacoustic 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)
PerceptionProductionunderlying form Phonologysurface form Phonetics universal phoneticmotor plan representationacoustic signal phonological encoding phonetic encoding phonological decoding phonetic decoding 0-12 months 12 months - ??
PerceptionProductionunderlying form Phonologysurface form Phonetics universal phoneticmotor plan representationacoustic signal phonological encoding phonetic encoding phonological decoding phonetic decoding 0-12 months Step 3 12 months - ??
PerceptionProductionunderlying form Phonologysurface form Phonetics universal phoneticmotor plan representationacoustic signal phonological encoding phonetic encoding phonological decoding phonetic decoding 0-12 months 12 months - ?? trial and error algorithms (Boersma 1999)
PerceptionProductionunderlying form Phonologysurface form Phonetics universal phoneticmotor plan representationacoustic 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’:[t u] |k u| assembled
surface form motor plan [t ] |k | Stage 2 [t , k ] |k | Storage of patterns ‘very’:[t ] |k |assembled ‘hole’:[t u] |k u| assembled
surface form motor plan [t ] |k | Stage 2 [t , k ] |k | Storage of patterns ‘very’:[t ] |k |retrieved from storage ‘hole’:[t u] |k u| assembled
surface form motor plan [t ] |k | Stage 3 [t , k ] |t , k | Correction of assembling rules ‘very’:[t ] |k |retrieved from storage ‘hole’:[t u] |k u| assembled
surface form motor plan [t ] |k | Stage 3 [t , k ] |t , k | Correction of assembling rules ‘very’:[t ] |k |retrieved from storage ‘hole’:[t u] |t u| assembled
surface form motor plan [t ] |t | Stage 4 [t , k ] |t , k | Correction of stored patterns ‘very’:[t ] |k |retrieved from storage ‘hole’:[t u] |t u| assembled
surface form motor plan [t ] |t | Stage 4 [t , k ] |t , k | Correction of stored patterns ‘very’:[t ] |t |retrieved from storage ‘hole’:[t u] |t u| 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.