1
Q
High Amplitude Sucking Procedure
A
- 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 and Preference
2
Q
Discrimination Procedure
A
- 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: Hears new speech stimulus every time produces a strong suck
- If can distinguish between stimuli, sucking behaviour should increase
3
Q
Preference Procedure
A
- 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
4
Q
Preferential Listening Procedure
A
- 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
5
Q
Speech Perception in Infancy
A
- 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
6
Q
Categorical Perception of Speech
A
Adults perceive speech sounds as distinct categories even though the differences between speech sounds are gradual
- 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
7
Q
Infant Categorical Perception of Speech
A
- Do infants perceive the same speech categories as adults?
- Classic study by Eimaset 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 msVOT) and then tested with /pa/ (40 msVOT)
*Same speech sounds: Infants habituated to 60 msVOT /pa/ and then tested with 80 msVOT /pa/
8
Q
Newborns have same categorical perception of speech as adults
A
- Different speech sounds: Increased sucking when sound from new category (/pa/)
- Same speech sounds: No change in sucking when sound from same category (/pa/)
9
Q
Infant Cross-Language Speech Perception
A
- 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
10
Q
Infant Cross-Language Speech Perception Experiment
A
- Classic study by Werkeret al., 1988:
–> Tested 6 month old 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/
11
Q
Implications
A
- 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 languag
12
Q
Perceptual Narrowing of Speech Perception
A
- Infants’ ability to easily distinguish between non-native speech sounds diminishes around 8 months
- By 10-12 months, infants’ perceptual abilities are narrowed to those sounds that are relevant to their native language
–> Improves perception of speech sounds in native language
13
Q
Word Segmentation
A
- Knowing where words begin and end in fluent speech
–> Begins around 7 months of age
-Infants’ statistical learning enables them to segment words in a stream of speech
–> Stress-patterning
–> Distribution of speech sounds
14
Q
Stress Patterning
A
- Different languages place stress on different parts of a word
–> English: stress usually on first syllable
–> French: stress usually on last syllable - Infants pick up on the stress patterning in their language and use it as clues to for word segmentation
15
Q
Distribution of Speech Sounds
A
- 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”)
16
Q
Distribution of Speech Sounds Study
A
- Preferential listening procedure
- Habituation: 8-month-olds 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
17
Q
Developmental Milestones
A
- 2 months: Cooing and gurgling
- 7 months: Babbling
- 12 months: First words
- 18 months: Knows 50 words
18
Q
Cooing
A
- 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
19
Q
Babbling
A
- 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 - Manual babbling: Deaf infants that are exposed to sign language babble with repetitive hand movements made up of pieces of full signs
–> Deaf children do not verbally babble
–> Evidence that language exposure is critical for babbling
20
Q
Functions of Babbling
A
- 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 alert 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
21
Q
Understanding Words Precedes Production
A
- Infants appear to understand high-frequency words around 6 months of age
–> In lab studies, when 6-month-olds are presented with pictures of common items and hear one of the pictures being named, they look to the correct picture more often than chance
–> But cannot yet name these items themselves - Shows that infants understand more words than they can produce
- Shows that infants understand more words than their caregivers realize
22
Q
First Words
A
- First words are produced around 12 months of age (10-15 months)
- First word: Any specific utterance consistently used to refer to a particular meaning
- Can be tricky to identify:
–> Babbling can sound like words
–> E.g. “mamamama”
–> Meaning of a first word can differ from its standard meaning
–> E.g. “woof woof” referring to “dog - 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
23
Q
Mispronunciations of First Words
A
- 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”
24
Q
Limitations of First Words
A
- 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
–> Does not mean that they don’t understand what the word refers to - Underextension: using a word in a more limited context than appropriate
–> “cat” only refers to the family’s pet cat
25
Learning More Words
- 18 months of age:
- Knows about 50 words
- Vocabulary spurt: Rate of word learning accelerates
26
How do Children Learn Words?
- Children’s assumptions about language
- Social context
--> Caregivers
--> Peers
27
Children's Assumptions in Word Learning
- Children have several assumptions when learning a new word:
--> Mutual exclusivity
--> Whole-object assumption
--> Grammatical form
--> Shape bias
--> Cross-situational word learning
--> Pragmatic cues
--> Adult’s intentionality
28
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
29
Whole-Object Assumption
A word will refer to the whole object rather than to a part or action of the object
30
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
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Grammatical Form
Grammatical form of a word influences whether it’s interpreted as a noun, verb, or adjective
32
Cross-Situational Word Learning
Determining word meanings by tracking the correlations between labels and meanings across context
33
Pragmatic Cues - Gaze
- 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
34
Pragmatic Cues - Tone of Voice
- 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
35
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
36
Infant-Directed Speech
- Distinctive mode of speech when talking to babies and toddlers
- Common in majority of cultures around the world, but not all cultures use it
- Characteristics:
--> Greater pitch variability
--> Slower speech
--> Shorter utterances
--> Clearer pronunciation of vowels
--> More word repetitions
--> More questions
--> Accompanied by exaggerated facial expressions
37
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
38
IDS and Early Word Recognition Study
- 7-8 month old infants were introduced to new words in IDS or regular adult speech
- Recognition of words tested 24 hours later using preferential listening procedure (familiarity)
- Infants were better at recognizing (looked longer at) words introduced in IDS than adult speech
- Indicates that IDS facilitates word learning
39
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
40
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 SE
--> Came to lab for an hour every week
--> Everything the parent and child said was recorded and analyzed
41
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
42
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
43
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
44
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
45
First Sentences
- 2 years of age:
--> Telegraphic speech: 2-3 wordphrases that leave out non-essential words
*E.g. “Mommy cake”, “Hurt knee”, “Key door”
*Common in many languages
46
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
*E.g. Adding “s” to makes a word plural
--> Over-regularization errors
47
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”
48
How is Grammar Learned?
- Parents and other caregivers:
--> Model grammatically correct speech but generally don’t correct children’s grammatical errors
- Statistical learning
49
How is Grammar Learned? 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)
--> E.g. : “le di di”, “wije 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 patter
50
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
51
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
52
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
53
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
54
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
55
Evidence: Deaf Individuals
- 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
56
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
57
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
58
Bilingualism is the Norm
- 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 Montrealersare English-French bilingual
--> 20% of Canadians’ first language is neither English nor French
59
"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
60
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 forEnglish
--> English-Tagalog bilinguals showed no consistent preference for either language
--> Suggests that bilingual infants start learning about two native languages pre-birth
61
Can bilingual infants differentiate between two native languages? Study
- 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 language
62
Two Separate Linguistic Systems
- Suggests that bilingual infants are developing two separate language systems
--> Rather than confusing 2 languages
- Goes against “monolingual brain” hypothesis
63
Evidence: Two Separate Linguistic Systems
1. The progression of 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
64
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 toquickly switch between languages, which practices their executive functioning skills, especially cognitive flexibility
65
Implications
Schools should support learning both native and non-native language from a young age
