ling 240: language and mind acquisition of phonology
TRANSCRIPT
Ling 240: Language and Ling 240: Language and MindMind
Acquisition of PhonologyAcquisition of Phonology
English
[p[phh]]
[b][b][p][p]
Hindi
[p][p][p[phh]]
[b][b]
EnglishEnglish Japanese Japanese
[l][l]
[r][r]
[l][l]
[r][r]
Voice onset timeVoice onset time
VOT = the time between the release VOT = the time between the release of a stop and the voicing of a of a stop and the voicing of a following vowelfollowing vowel
Voice Onset Time (VOT)
60 msec
Discrimination
0ms
20ms
40ms
20ms
40ms
60ms
D T
D
T T
D
Categorization of speech Categorization of speech soundssounds
We group sounds into categories, We group sounds into categories, despite physical variabilitydespite physical variability
Some physical differences are mentally Some physical differences are mentally represented as “not different”; others represented as “not different”; others as “different”as “different”
Is categorical perception innate?Is categorical perception innate?
How are mental categories acquired?How are mental categories acquired?
High Amplitude Sucking
Procedure• Initially sucking
rate increases (novelty)
• Then decreases• Decline in
response = habituation
LSCP Infant Lab
High Amplitude Sucking
Procedure
When sucking rate declines to a set point (habituation criterion),auditory stimulus is changed
LSCP Infant Lab
High Amplitude Sucking
ProcedureIf sucking rate increases,
then we know the infant has detected the change
• The renewed response = dishabituation
LSCP Infant Lab
Newborns are universal listeners
Infants perceive speech categorically
Newborns are sensitive to almost every phonological distinction yet tested
Newborns are universal listeners
In contrast, adults have difficulty discriminating speech sounds that are not contrastive in their native language
Hindi contrastsHindi contrasts
[dããt][dããt] toothtooth [DããT][DããT] scold, be angry withscold, be angry with
[taal][taal] ‘musical note’‘musical note’ [Taal][Taal] ‘to ignore’‘to ignore’
Newborns are universal listeners
English infants can distinguish Hindi /d/ and /D/
Japanese infants can distinguish between /l/ and /r/
Studies by Werker et alStudies by Werker et al
Infants are universal listeners but adults can’t discriminate non-native phonemic contrasts
Then there must be a decline across age
Questions: Questions: what is the role of experience?what is the role of experience? when exactly does this decline happen?when exactly does this decline happen? is this decline a critical period effect?is this decline a critical period effect?
Testing Across the Lifespan
• young infants
• older infants
• children and adults
Conditioned Head Turn Paradigm
Habituation (High Amplitude Sucking)
Just ask them: “Same or different?”
Visual Reinforcer (VR)
Toy that lights up and moves at the experimenter’s command
Controls for sound stimuli and the VR
Conditioned Head Turn• Child hears Stimulus 1 (/ba/)
repeatedly• Then Stimulus 2 is presented
(/da/)• If child detects difference, he
should turn to look at the visual reinforcer when the stimulus changes
• If child does not detect it, he shouldn’t turn
Conditioned Head Turn Paradigm
Kuhl Lab, U Washington, 1992
Werker 1995
Testing /ba/ vs. /da//Ta/ vs. /ta//tha/ vs. /dha/
Subjects: Hindi adultsEnglish AdultsEnglish 6-8 month-
olds
Werker 1995
/ba/ vs. /da/ Hindi and English
/Ta/ vs. /ta/ Only Hindi
/tha/ vs. /dha/ Only Hindi
Results
Werker, 1995
QuestionsQuestions
When does decline in When does decline in performance take place?performance take place?
What exactly is responsible What exactly is responsible for the decline?for the decline?
Does Does Critical PeriodCritical Period play a play a role?role?
General Methodology General Methodology questionquestion
We observe that infants behave one We observe that infants behave one way and adults behave another way.way and adults behave another way.
Goal: Goal: We want to know what changes We want to know what changes at what point in time.at what point in time.
What are some ways of obtaining What are some ways of obtaining this data?this data?
Werker & Tees 1984
Test infants of different ages (Cross-sectional)Test infants of different ages (Cross-sectional) Test the same group of infants at different Test the same group of infants at different
points in time (Longitudinal)points in time (Longitudinal)• 6-8 months6-8 months• 8-10 months8-10 months• 10-12 month10-12 month
Werker & Tees 1984: Werker & Tees 1984: NthlakampxNthlakampx
Native American language spoken by Native American language spoken by about 200 speakers (in 1984) in about 200 speakers (in 1984) in British Columbia—also known as British Columbia—also known as Thompson or SalishThompson or Salish
Nthlakampx Nthlakampx glottalized velarglottalized velar vs vs glottalized uvularglottalized uvular ejectives ejectives
[‘ki][‘ki] vs vs [‘qi][‘qi] Velar Velar ‘k..‘k.. Uvular Uvular ‘q…‘q…
Results
Werker & Tees, 1984
Werker studies: Conclusion
Ability to perceive non-native contrasts declines in 1st year
Werker and Tees 1984
What is responsible for the change?
How do babies become adults?
First proposal: First proposal: Maintenance/Loss Maintenance/Loss
HypothesisHypothesis role of experience is to role of experience is to
maintain perceptual maintain perceptual sensitivitiessensitivities
lack of exposure leads to loss lack of exposure leads to loss of perceptual abilityof perceptual ability
Maintenance/Loss Model
Ability
Time
Experience
1 year
No experience
ProblemsProblems for the for the Maintenance/Loss Maintenance/Loss
HypothesisHypothesis
Prediction?Prediction?
Decline in sensitivity following lack of exposure should bepermanent and absolute
Problems for the Problems for the Maintenance/Loss Maintenance/Loss
HypothesisHypothesisPredictions are not borne out: (1)Predictions are not borne out: (1)
Adults CAN perceive non-native Adults CAN perceive non-native contrasts contrasts
in (perceived) non-speech tasksin (perceived) non-speech tasks Zulu clicksZulu clicks
The link to listen to Zulu clicksThe link to listen to Zulu clickshttp://www.youtube.com/watch?v=gytCi5a7AJg
sounds in isolation (not syllables)sounds in isolation (not syllables)
Problems for the Problems for the Maintenance/Loss Maintenance/Loss
HypothesisHypothesis
Predictions are not borne out: (2)Predictions are not borne out: (2) Children older than 12 months Children older than 12 months
can move to a new country can move to a new country and acquire native phonologyand acquire native phonology
Alternative Hypothesis: Alternative Hypothesis: Functional ReorganizationFunctional Reorganization
no absolute hardware changes no absolute hardware changes in auditory systemin auditory system
development of a linguistic development of a linguistic system that imports a subset system that imports a subset of the contrasts from the of the contrasts from the auditory systemauditory system
ConclusionsConclusions
So, So, what changes during the first year?what changes during the first year? Answer:
the baby starts to acquire a linguistic system
As babies acquire a linguistic system As babies acquire a linguistic system (words) in their first year, they (words) in their first year, they “learn” which distinctions need to be “learn” which distinctions need to be represented represented in that systemin that system