Ling 240: Language and Mind

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Ling 240 Language and Mind

• Acquisition of Phonology

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English

p
b
ph
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Hindi

p
b
ph
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English Japanese
l
l
r
r
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Voice onset time

• VOT the time between the release of a stop and
  the voicing of a following vowel

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Voice Onset Time (VOT)
60 msec
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Discrimination
D
0ms
20ms
D
D
20ms
40ms
T
40ms
60ms
T
T
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Categorization of speech sounds

• We group sounds into categories, despite physical
  variability
• Some physical differences are mentally
  represented as not different others as
  different
• Is categorical perception innate?
• How are mental categories acquired?

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High Amplitude Sucking Procedure

• Initially sucking rate increases (novelty)
• Then decreases
• Decline in response habituation

LSCP Infant Lab
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High Amplitude Sucking Procedure
When sucking rate declines to a set point
(habituation criterion), auditory stimulus is
changed
LSCP Infant Lab
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High Amplitude Sucking Procedure

• If sucking rate increases,
• then we know the infant has detected the change
• The renewed response dishabituation

LSCP Infant Lab
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Newborns are universal listeners

• Infants perceive speech categorically
• Newborns are sensitive to almost every
  phonological distinction yet tested

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Newborns are universal listeners

• In contrast, adults have difficulty
  discriminating speech sounds that are not
  contrastive in their native language

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Hindi contrasts

• dããt tooth
• DããT scold, be angry with
• taal musical note
• Taal to ignore

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Newborns are universal listeners

• English infants can distinguish Hindi /d/ and /D/
• Japanese infants can distinguish between /l/ and
  /r/

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Studies by Werker et al

• Infants are universal listeners but adults cant
  discriminate non-native phonemic contrasts
• Then there must be a decline across age
• Questions
• what is the role of experience?
• when exactly does this decline happen?
• is this decline a critical period effect?

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Testing Across the Lifespan

• young infants
• older infants
• children and adults

Habituation (High Amplitude Sucking)
Conditioned Head Turn Paradigm
Just ask them Same or different?
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Visual Reinforcer (VR) Toy that lights up and
moves at the experimenters command
Controls for sound stimuli and the VR
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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 shouldnt turn

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Conditioned Head Turn Paradigm
Kuhl Lab, U Washington, 1992
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Werker 1995
Subjects Hindi adults English
Adults English 6-8 month-olds
Testing /ba/ vs. /da/ /Ta/ vs.
/ta/ /tha/ vs. /dha/
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Werker 1995
/ba/ vs. /da/ Hindi and English /Ta/ vs.
/ta/ Only Hindi /tha/ vs. /dha/ Only Hindi
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Results
Werker, 1995
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Questions

• When does decline in performance take place?
• What exactly is responsible for the decline?
• Does Critical Period play a role?

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General Methodology question

• We observe that infants behave one way and adults
  behave another way.
• Goal We want to know what changes at what point
  in time.
• What are some ways of obtaining this data?

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Werker Tees 1984

• Test infants of different ages (Cross-sectional)
• Test the same group of infants at different
  points in time (Longitudinal)
• 6-8 months
• 8-10 months
• 10-12 month

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Werker Tees 1984 Nthlakampx

• Native American language spoken by about 200
  speakers (in 1984) in British Columbiaalso known
  as Thompson or Salish
• Nthlakampx glottalized velar vs glottalized
  uvular ejectives
• ki vs qi
• Velar k..
• Uvular q

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Results
Werker Tees, 1984
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Werker studies Conclusion
Ability to perceive non-native contrasts declines
in 1st year
Werker and Tees 1984
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What is responsible for the change? How do
babies become adults?
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First proposal Maintenance/Loss Hypothesis

• role of experience is to maintain perceptual
  sensitivities
• lack of exposure leads to loss of perceptual
  ability

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Maintenance/Loss Model
Ability
Experience
No experience
1 year
Time
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Problems for the Maintenance/Loss Hypothesis

• Prediction?

Decline in sensitivity following lack of exposure
should be permanent and absolute
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Problems for the Maintenance/Loss Hypothesis

• Predictions are not borne out (1)
• Adults CAN perceive non-native contrasts
• in (perceived) non-speech tasks
• Zulu clicks
• The link to listen to Zulu clicks
• http//www.youtube.com/watch?vgytCi5a7AJg
• sounds in isolation (not syllables)

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Problems for the Maintenance/Loss Hypothesis

• Predictions are not borne out (2)
• Children older than 12 months can move to a new
  country and acquire native phonology

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Alternative Hypothesis Functional Reorganization

• no absolute hardware changes in auditory system
• development of a linguistic system that imports a
  subset of the contrasts from the auditory system

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Conclusions

• So, what changes during the first year?
• Answer the baby starts to acquire a linguistic
  system
• As babies acquire a linguistic system (words) in
  their first year, they learn which distinctions
  need to be represented in that system