Segmentation

Segmentation problem

Challenge of figuring out where one word ends and the next begins in the continuous stream of speech

What age can infants segment words

7.5 mos, not 6 mos, unless if you add info (their name)

Early on infants only segment…

• single syllable words

• words with strong first syllables (REcord not reCORD)

• words with good phonotactic cues

If two words rarely occur next to each other babies are likely to think…

Likely to think there is a word boundary between them

• bas/ving

If two sounds occur next to each other a lot babies are likely to think…

Likely to think there is no word boundary between them and the boundary is somewhere else

• ba/sling

Problem with phonotactics and segmentation?

Require babies to already know the words to recognize these patterns

What do infants use to segment continuous speech streams

Syllable co-occurence

Gavagai problem

Challenge of figuring out what a new word actually refers to when you hear it for the first time

Whole object assumption

A new label is likely to refer to the whole object and not its parts, substance, etc

Disambiguation

Assume a new word refers to the thing they don’t already have a label for

• ‘find the dax’

Social cues from speaker

• Infants use eye gaze'

• 18 mos old map word onto object that speaker is looking at, not what they themselves are looking at

Thematic

• Based on how things go together in events

• dog → dog toy

• cat → cat toy

• Infants rely on this

Taxonomic

• Based on categories or shared features

• Dog → cat

• Dog toy → cat toy

When do children group things taxonomically?

New labels pushes children to group items taxonomically

Speech directed to children

Here and now

How do adults label objects

label things children are looking at (not always)

When is word learning better

Children learn words better when the label matches their current focus, rather than when adults try to redirect their attention elsewhere

What matters more: child’s gaze or word frequenct

Childs gaze

What predicts reliable production of a word (or protoword)

• frequency

• easier sentence structure

• shorter length

• contextual distinctiveness

Contextual distinctiveness

When a word or object is easier to learn because it appears in a unique or noticeable situation

Why are nouns learned first?

• whole object bias

• more visually obvious

• fewer cross linguistic differences

• emphasis in the language/by parents

Word spurt

sudden increase in the number of words a toddler learns, usually around 18–24 months