phonetic detail in developing lexicon daniel swingley 2010/11/051presented by t.y. chen in 599
TRANSCRIPT
Presented by T.Y. Chen in 599 1
Phonetic Detail in Developing Lexicon
Daniel Swingley
2010/11/05
Presented by T.Y. Chen in 599 2
The issue
• Do infants/children store every piece of phonetic details of words in the lexicon in the very beginning stage of phonological acquisition?
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Continuous debates
• Jusczyk & Aslin (1995): 7.5 mo infants can encode initial segment (e.g. /k/ in cup vs. /t/ in tup) by listening just a few tokens.
• Halle & de Boysson-Bardies (1996): 11 mo French infants have the preference of ponjour and vonjour after listening to bonjour. (A global representation of [+labial])
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Author’s view
• The results in the previous studies are not entirely reliable…
• Metalinguistic responses are required; it is just difficult to get any overt response…
• Production tasks are not ideal to test children’s receptive forms in the lexicon…
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Experiment Design
• Visual fixation: no overt response is needed.
• If children can discriminate phonetic details, the visual fixation on the target picture will be different.
• Participants: Dutch learning children ranged from 18;07 (months;days) to 20;17.
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Hypothesis I
• At first, children have only global representations of words (e.g. [+labial] for bonjour), unless they also learn some minimal-pair words (e.g. vonjour) that help them to distinguish one sound from the other.
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Experiment I
• Stimuli:CP - bal ‘ball’, beer ‘bear’MP – onset substitution of /g/ and /d/(Only dal ‘valley’ is a real word in Dutch)
• If the children only have global representations of the two words, they should not be able to distinguish, for example, beer from geer or deer.
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Experiment I
• Task:Pictures of ball and bear are presented respectively; children look at the pictures and listen to the stimuli of Waas is de [target] (Where is the [target]).
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Experiment I
• Result:
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Experiment I
• Results:Children fixate the targets longer in the CP condition (p=.03).
• Children do not need to know any minimal-pair word to distinguish sounds; the phonetic details of a word are stored in the lexicon, which can be used for the sound discrimination.
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Hypothesis II
• Children might learn a minimal-pair word due to misparsing of word boundaries. For example, peer can be learned from a longer word #___+peer# as a possible minimal-pair word of beer.
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Experiment II
• Stimuli:CP – baby ‘baby’, beker ‘cup’MP – Word-medial substitution with /d/ and /g/ (e.g. bady or bagy).
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Experiment II
• 2 minimal-pair words for beker are zeker and beter.
• Yet there is no possible minimal-pair word for baby, even with misparsing:e.g. No instance of ba#gy or #___+bagy#
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Experiment II
• Word-medial substitution rules out the possibility that children discriminate sounds solely by the very first part of a word.
• For example, children might know the target is baby instead of car by just hearing ba…
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Experiment II
• Result:
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Experiment II
• Results:The children again fixate longer on the target picture in the CP condition! (p=.03)
• No correlation with the children’s receptive and productive vocabularies reported by their parents (r=.06, r=.07).
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Author’s Conclusions
• Children store every phonetic detail in the lexicon; acquiring minimal-pairs is not a prerequisite for them to distinguish sounds.
• Why do some children fail to demonstrate the sound discrimination? They do encode the details, but they may forget which form corresponds to which word.
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Follow-up Question I
• Is it enough to make the conclusion by testing just one single segment in each experiment? If children retains phonetic details completely, shouldn’t we test the discrimination of every segment in the stimuli?
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Follow-up Question II
• Does the phonotactic distribution help the children to identify the sound contrasts? For example, in English, none of baby, pig, beckon, happy, brush, and pickles can form minimal-pairs, but they show a /b/-/p/-/k/ onset contrast.
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Follow-up Question III
• Is it possible that these children ‘watch’ too many English TV shows and learn/hear some minimal-pair words from them??
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