Language Development Flashcards
Speech Perception: High Amplitude Sucking Procedure
High Amplitude Sucking Procedure
* Used to test infants from birth to 4 months of
age
* Relies on infants sucking reflex
* Infants hear a sound stimulus every time they
produce a strong/ high-amplitude suck on a
pacifier
* The number of strong sucks is an indicator of the
infant’s interest * More strong sucks = more interest
* 2 variations of procedure: * Discrimination * Preference
- Discrimination:
- Used to test whether infants can tell the difference between two
auditory stimuli - Variation of visual habituation paradigm
- Habituation phase: Each time infant produces a strong suck, a sound is
played * Continues until sucking has declined significantly (e.g. by 20%) - Test phase: Hear new speech stimuli every time produces a strong suck* If can distinguish between stimuli, sucking behaviour should increase
- Preference:
- Used to test infants’ preference for different stimuli
- 2 different stimuli are played on alternating minutes each time a strong
suck is produced
-i.e., minute 1 = Stimulus A, minute 2 = Stimulus B, minute 3 = Stimulus A* Number of strong sucks produced during presentation of each stimulus
type is compared - Preference = infants suck more during one stimulus minute type than
the other
Speech Perception in Infancy
* Using high amplitude sucking paradigms, research has shown that
newborns:
* Prefer to listen to speech sounds over artificial sounds
* Prefer mother’s voice over another woman’s voice
* Prefer to listen to native language vs. other language
* Suggests that language learning starts in utero!
Speech: Categorical perception of speech
Perceiving Speech Sounds
* Speech perception relies on perceiving differences between speech
sounds
* Examples:
* /a/ is different than /e/ and /i/
Categorical Perception of Speech
* Often what distinguishes similar speech sounds is voice onset
time (VOT):
- Length of time between when air passes through the lips and when
the vocal cords start to vibrate
* Categorical perception: We perceive speech sounds as distinct
categories even though the differences between speech sounds is
gradual
Example: /b/ to /p/ Continuum
* Produced in the same way except for voice onset time
* Continuum of /b/ to /p/ by gradually varying voice onset time
* Categorical perception is useful because focuses listeners on sounds
that are linguistically meaningful while ignoring meaningless
differences
* E.g. difference between a 10ms VOT /b/ vs. 20ms VOT /b/ is meaningless
in English
Infant Categorical Perception of Speech
* Do infants perceive the same speech categories as adults?
* Classic study by Eimas et al., 1971:
* Tested 1 month old infants learning English
* High amplitude sucking paradigm to test discrimination between /ba/
and /pa/
* 2 groups: * Different speech sounds: Infants habituated to /ba/ (20 ms VOT) and then
tested with /pa/ (40 ms VOT) * Same speech sounds: Infants habituated to 60 ms VOT /pa/ and then
tested with 80 ms VOT /pa/
Different
speech sounds:
Increased
sucking when
sound from new
category (/pa/)
Same speech
sounds:
No change in
sucking when
sound from same category (/pa/
* Newborns have same categorical perception of speech as adults!
Infant Cross-Language Speech Perception
- Infants make more distinctions between speech sounds than adults
- Adults have difficulty perceiving differences between speech sounds
that are not important in their native language - E.g. In French, difference between /ou/ and /u/ is meaningful, but not in
English - What about infants?
- Classic study by Werker et al., 1988:
- Tested 6 month olds American infants learning English
- High amplitude sucking paradigm to see if they can discriminate
between Hindi /Ta/ and /ta/ - English speaking adults struggle to distinguish between these 2 sounds
- Results:
- After habituating to one of these Hindi speech sounds, increased sucking
when heard other speech sounds - i.e., if habituated to /Ta/, then increased sucking when tested with /ta/
Implications
* Infants discriminate between speech sounds they have never heard
before (i.e., speech sounds not found in their native language)
* Infants are biologically ready to learn any of the world’s languages
Perceptual Narrowing of Speech Perception * Diminishes around 8 months
* Infants lose ability to discriminate between non-native speech sounds
at 10-12 months of age
* Improves perception of speech sounds in native language
From Perceiving Speech Sounds to Words
- Word segmentation: discovering where words begin and end in
fluent speech - Begins around 7 months of age
- Pick-up on patterns of native language via statistical learning
- Stress-patterning
- Distribution of speech sounds
Stress Patterning
* Different languages place stress on different parts of a word
* English: stress usually on first syllable
* French: stress usually on last syllable
Distribution of Speech Sounds
* Sounds that appear together often are likely to be words
* Sounds that don’t appear together often are more likely to be
boundaries between words.
- Example: “happy baby”
- “ba” and “by” occur together often because make word “baby”
- “ha” and “ppy” occur together often because make word “happy”
- “ppy” and “ba” occur together less often because don’t make a word and
many different words can come before “baby” (“happy”, “little” ) and
many words can come after “happy” (“birthday”, “baby”, “puppy”)
Preferential Listening Procedure
* Speaker on either side of infant’s head
* When looks at speaker, a recording of
speech plays
- Different speech from each speaker
* How long an infant spends looking in a
particular direction/ listening to a particular
sound indicates how much they like it
- Familiarity effect: Will listen longer to sounds
they recognize
- Novelty effect: If first habituated to a sound, will
listen longer to new sound
Have to be minimum 4 months old, if not baby doesn’t have motor skills to look around
- Study: Preferential listening procedure
- Habituation: 8 month old listened to a stream of
syllables for a long time (2 mins) - Some syllables always occurred together
- Others rarely or never occurred together
- Test: Presented with a syllable sequence that always co-occurred (“tokibu”) vs. syllable sequences
that rarely co-occurred (“bagopi”) - Results: Listened longer to rarely occurring
sequence - Shows that infants understood word boundaries
by detecting the likelihood of syllables belonging
together
Summary of Speech Perception
- Speech perception is studied with high amplitude sucking procedure
and preferential listening paradigm - Infants have remarkable speech perception abilities
- From birth, show adult-like categorical perception of speech for sounds
that are physically similar and able to distinguish between speech
sounds not found in their native language - As they learn sounds of their native-language, lose ability to distinguish
between non-native sounds at 10-12 months of age - Infants are sensitive to the patterns of language and use it to
segment words from speech beginning around 7 months of age
The Journey to First Words
2 months: cooing and gurgling
7 months: babbling
12 months: first words
18 months: knows 50 words
Cooing
* Start around 2 months of age
* Drawn out vowel sounds, like “ooooohhh” and “aahhhh”
* Helps infants gain motor control over their vocalizations
* Elicits reactions from caregivers leading to back-and-forth cooing
with caregivers
Babbling
* Start around 7 months of age (6-10 months of age)
- Repetitive consonant-vowel syllables, like “papapa” and “babababa”
- Speech sounds not necessarily from native language
* Infant babbling is very similar across languages
* Deaf infants that are exposed to ASL babble with repetitive hand
movements made up of pieces of full ASL signs
- Evidence that language exposure is critical for babbling
Functions of Babbling
* Social function: Practicing turn-taking in a dialogue
- Infant babbling elicits caregiver reactions which in turn elicit more
babbling
* Learning function: Signal that the infant is listening and ready to
learn
- Infants learn more when an adult labels a new object just after
they babble vs. learning the word in the absence of babbling
Understanding Words Before First Words
* Infants appear to understand high-frequency words around 6
months of age
* Study:
* Show infants pictures of common items and monitor where they look
when one of the pictures is named (eye-tracking).. adult wears visor to not bias baby’s answer
* 6 month olds look to the correct picture more often than chance
* Shows that infants understand more words than they can produce
* Shows that infants understand more words than their caregivers realize
First Words
* First word: Any specific utterance consistently used to refer to or
express a meaning
* Can be tricky to identify:
* Babbling can sound like words
- E.g. “mamamama”
* Meaning of a first word can differ from it’s standard meaning
- E.g. “gulgul” referring to “turkey”
* First words are produced around 12 months of age (10-15 months)
* Often mispronounced in predictable ways:
* Omit difficult parts of words:
- “Banana” “nana”
* Substitute difficult sounds for easier sounds:
- “Rabbit” “wabbit”
* Re-order sounds to put easy sound first
- “Spaghetti” “pisketti”
* Usually refer to family members, pets, or important objects
* Meaning of first words are very similar across cultures
- Suggests that infants around the world have similar interests and
priorities
Limitations of First Words
* Infants express themselves initially with only one word utterances so
cannot clearly communicate what they want to say
* Overextension: using a word in a broader context than is
appropriate
- E.g. “dog” refers to any 4 legged animal
* Underextension: using a word in a more limited context than
appropriate
- “cat” only refers to the family’s pet cat
Learning More Words
* 18 months of age:
* Knows about 50 words
* Vocabulary spurt: Rate of word learning accelerates
Word Learning: Children’s assumptions about language
How do Children Learn Words?
* Children’s assumptions about language
* Social context
- Caregivers
- Peers
Children’s Assumptions in Word Learning
* Children have several assumptions when learning a new word:
* Mutual exclusivity
* Whole-object assumption
* Pragmatic cues
* Adult’s intentionality
* Grammatical form
* Shape bias
* Cross-situational word learning
Mutual Exclusivity Assumption
* A given object/being will have only one name
- A child will turn their attention to the object they don’t have a name for
when they hear a new word
- Bilingual children will follow this rule less
Whole-Object Assumption
* A word will refer to the whole object rather than to a part or action of
the object
Pragmatic Cues
* Using the social context to infer the meaning of a word
* Adult gaze: When an adult says a new word, the child assumes that
it refers to the object the adult is looking at, even if the child cannot
see it
Adult’s Intentionality
* If an adult uses a word that conflicts with child’s word for that object, they will learn the new word if it is said with confidence
Grammatical Form
* Grammatical form of a word influences whether it’s interpreted as a
noun, verb, or adjective
Shape Bias
* Children will apply a noun to a new object of the same shape, even if
that object is very different in size, colour, or texture
Cross-Situational Word Learning
* Determining word meanings by tracking the correlations between
labels and meanings across contexts
*see all the examples
Word Learning: Social Context
Caregiver Influence on Word Learning
* Children’s vocabularies are hugely impacted by the vocabularies and
speech of their caregivers
* Caregiver factors influencing word learning:
* Infant directed speech
* Quantity of speech
* Quality of speech
Infant-Directed Speech (IDS)
* Distinctive mode of speech when talking to babies and toddlers
* Common in majority of cultures around the world
* Characteristics:
* Greater pitch variability
* Slower speech
* Shorter utterances
* Clearer pronunciation of vowels
* More word repetitions
* More questions
* Accompanied by exaggerated facial expressions
Function of Infant-Directed Speech
* Draws infants’ attention to speech
- Infants prefer IDS to regular adult speech
* Because infants pay greater attention to IDS, it facilitates their
language learning
IDS and Early Word Recognition
* Study:
* 7-8 month old infants were introduced to new words either in:
- Infant directed speech
- Regular adult speech
* Recognition of words tested 24 hours later using preferential listening
procedure
- All speech in recognition testing presented in IDS
- How long do infants look in the direction of the word introduced in IDS
vs. word introduced in adult speech?
Results:
* Infants looked longer at words introduced in IDS than adult speech
* Indicates that IDS facilitates recognition of words
Quantity of Speech
* The number of words children hear used around them predicts
children’s vocabulary size
- Especially speech directed to child
* Children that hear more words have larger vocabularies
Quantity of Speech and SES
* Classic study found that parents’ SES predicts how much speech
infant hear
* Method: Tested parents with their 7 month old children over 2.5 years
until the child turned 3 years of age
- High, middle, and low SES
- Came to lab for an hour every week
- Everything the parent and child said was recorded and analyzed
Results:
Gap of 30 million words between welfare vs. professional income groups
Implications of Effect of SES
* Children from high SES have larger vocabularies than kids from low
SES
* Differences in language exposure contribute to achievement gap
between higher and lower SES children
Quality of Speech
* Richness of adult communication with their child predicts children’s
language ability:
* Joint engagement
* Fluency
* Stressing and repeating new words
* Playing naming games
* Naming an object when a toddler is already looking at it
Intervention to Close Word Gap
Grocery Store Intervention
* Focuses on increasing amount of time parents spend talking to child
* Signs placed in grocery stores in low SES neighbourhoods encouraging
parents to talk to their children about the foods in the store
* Parents increased quantity and quality of speech to their child
Peers’ Influence on Language
* Placing preschool children with similarly poor language ability in the
same classroom negatively impacts their language growth
* Better chance to “catch-up” on language ability if:
* placed with children with higher language ability
* teacher uses rich communication with students
Summary of Journey to First Words
- Cooing: 2 months of age
- Babbling: 7 months of age
- First words:
- Understand high-frequency words at 6 months of age
- Say first words at 12 months of age
- Children use a variety of strategies to figure out what words mean
- Children’s vocabularies are hugely influenced by social context
Putting Words Together
First Sentences
* 2 years of age:
- Telegraphic speech: 2-3 word phrases that leave out non-essential
words
- E.g. “Mommy cake”, “Hurt knee”, “Key door” * Common in many languages
Learning Grammar
* Age 5: Mastered basics of grammar
- Allows children to express and understand more complex ideas
* We know that children have learned the grammar of their language
when they can apply a grammatical rule to a new word/context
* Examples:
- Adding “s” to makes a word plural
Overregularization Errors
* Speech errors in which children treat irregular forms of words as if
they were regular
* Evidence that they have learned grammatical rules but not the
exceptions to the rule
* Examples:
* “Mans”
* “Goed”
* “Foots”
* “Breaked”
* “Branged”
How is Grammar Learned?
* Parents and other caregivers:
- Model grammatically correct speech but generally don’t correct
children’s grammatical errors
* Statistical learning
* Study: Can infants pick up on new grammatical patterns?
* Preferential listening paradigm
* Habituated to a list of 3-“word” sequences in which second “word” is
repeated (ABB structure)
- “le di di” - “wi je je” - “de li li”
* Test: Presented with new sentences with same structure (ABB) or with a
different structure (ABA)
- ABB: “ko ga ga” vs. - ABA: “ko ga ko”
* Results: 8 month olds look longer in direction of sentences with
different structure
* Evidence that infants can pick-up on grammatical patterns
From Sentences to Conversations
* 1-4 years old: Children initially struggle to engage in mutual
conversation
* Private speech
- Infants’ speech is often initially directed to themselves to organize actions
* Egocentric discussion between children
* 5+ years old: able to stick to the same conversation topic as their
conversation partner
Summary of Putting Words Together
* Age 2: produce 2-3 word sentences
* Length and complexity of sentences gradually increases
* Age 2-5: Acquiring the basics of grammar
* Extend patterns, like “add –s to make plural”
* Overgeneralization errors
* Age 5: master grammar and beginning to be able to engage in
sustained conversations
Nature vs. Nurture?
Sensitive Period for Language Acquisition
* Period from birth to before puberty
- Due to maturational changes in the brain whereby language brain areas
become less plastic
* Crucial period in which an individual can acquire a first language if
exposed to adequate linguistic stimuli
- Languages are learned relatively easily during this period and full native
competence is possible
* After this period, languages are learned with great difficulty and
native-like competence is rare
Evidence: Genie
* Discovered in LA in 1970
* From 18 months old until she was rescued at age 13,
deprived of linguistic input
* Could barely speak
* Development also stunted in all other areas
* Language ability never fully developed despite
intensive training after age 13
* “Father take piece wood. Hit. Cry.”
* Evidence of sensitive period of language acquisition
* BUT difficulties may be due to inhumane treatment
rather than linguistic deprivation per se
Evidence: Recovery after Brain Damage
* Children that sustain brain damage to language areas usually recover
full language capability
- Children’s brains are highly plastic; other parts of the developing brain
can take over language functions
* Teenagers and adults that sustain brain damage to language areas
are more likely to suffer permanent language impairment
- More mature brain is less plastic
Evidence: Deaf Individuals
* Researchers tested 2 groups of deaf adults:
1. No exposure to language during early childhood
2. Learned spoken language during early childhood
* Both groups began learning ASL in school between
ages of 9-15
* Results: Those with exposure to language in
infancy, even though spoken, performed better on
language task than those with no language
exposure
* Follow-up study tested deaf adults that had
exposure to ASL in early childhood
* Performance of deaf adults with early
exposure to ASL was the same as deaf
adults with exposure to spoken language
* Shows that exposure to language,
regardless of modality, in infancy is critical
for full language development
Evidence: Second Language Learners
* Performance on an English test by Chinese
and Korean immigrants was related to the
age at which they first arrived in the USA
* Shows that language proficiency is related
to first age of exposure to that language
* Language performance is highly variable
when a language is learned after puberty
Summary
* Birth-before puberty: sensitive period for language acquisition
* Many aspects of language are difficult to learn after this period
* Language development is thus governed by both nature (sensitive
period) and nurture (language exposure is critical during this period)
Implications of Sensitive Period
* Deaf children should be exposed to sign language as young as
possible to develop native-like ability
* Second language exposure at school should begin as early as possible
to maximize opportunity to achieve native-like ability
Growing Up Bilingual
- About 50% of people across the world use at least 2 languages on a
daily basis - In Canada,
- 17% of Canadians are English-French bilingual
- 55% of Montrealers are English-French bilingual
- 20% of Canadians’ first language is neither English nor French
The Myth of the Monolingual Brain
* “Monolingual brain” hypothesis: Belief that infants’ brains are
programmed to be monolingual and that they treat input in 2
languages as if it were one language
- Bilingualism stretches limited processing capacity of infants
* Implications:
- If bilingual from birth, children will confuse their languages and could
result in language delays
Bilingualism in Utero
* Bilingual learning begins in utero
* Study:
* Tested 2 groups of newborn infants
- Bilingual English-Tagalog mothers
- Monolingual English mothers
* Preferential high amplitude sucking procedure
- Exposed infants to Tagalog and English sentences
- Measures rate of sucking on a pacifier
- More intense sucking indicates preference for one language
* Results:
- English monolinguals had a preference for
English
- English-Tagalog bilinguals showed no
consistent preference for either language
* Suggests that bilingual infants start
learning about two native languages prebirth
- Can bilingual infants differentiate between two native languages?
- Study: Tested 2 groups of newborn infants
- Bilingual English-Tagalog mothers
- Monolingual English mothers
- Discrimination high amplitude sucking procedure:
- Habituation: Both groups habituated to English or Tagalog until
sucking declined - Test: hearing sentences in new language
- Results:
- Both bilingual babies and monolingual
babies differentiated between Tagalog and
English - Shows that bilingual infants can differentiate
between native languages despite showing
similar preference for both languages
Two Separate Linguistic Systems
* Suggests that bilingual infants are developing two separate language
systems
- Rather than confusing 2 languages
* Goes against “monolingual brain” hypothesis
Evidence: Two Separate Linguistic Systems
1. Language development in bilingual vs. monolingual children is very
similar
* E.g., Say their first word roughly at the same time
* Have about the same vocabulary size when considering both languages
* Smaller vocabulary in each language separately vs. monolinguals
2. Children select language they use based on conversational partner
3. Even if children mix languages, not a sign of confusion
* Language mixing in adult bilinguals is normal
* 90% of bilingual parents mix their languages in speech
Advantages of Bilingualism
* Bilingual children perform better on measures of executive
functioning than monolingual children
* Bilingualism seems to delay onset of Alzheimer’s in older adults
* Why advantageous?
- Bilingual individuals have to quickly switch between languages, which
practices their executive functioning skills, especially cognitive flexibility
Implications
* Schools should support learning both native and non-native
language from a young age
Summary
* Contrary to monolingual brain hypothesis, bilingual children
simultaneously acquire a linguistic system for each of their languages* Start learning both (or more) languages of the family in utero
* Bilingual language development is very similar to monolingual
development
