TASK 6 N A T I V E-L A N G U A G E S E N SI T I V I T I E S : E V O L U T I O NI N F I R S T Y E A R O F L IFE( A R T I C L E-G A L L E S)

Question 1

What can infants do that decline over with age and how?

Answer 1

First few months of life, infants can perceive differences in non-native sounds, but that declines with age.

 First months – Infants perceive differences in phonetic contrasts not in environment and that parents cannot discriminate.
 Infants are able to perceive any speech contrast because they can use general perceptual acoustic capacities.
 Between 6 – 12 months – Ability to perceive non-native sounds declines and that of native sounds ameliorates.
 Thus, pattern of discrimination approaches that of parents.
 As a consequence of experience with native language, language-specific mechanisms are available to process speech signal.

Question 2

What is categorical perception?

Answer 2

Characterized by the enhanced capacity to perceive exemplars belonging to different categories and difficulty in perception of different tokens belonging to same category

Question 3

Head turn procedure

Answer 3

– Infants (6 – 12 months) learn to turn their head towards attractive toy every time they hear a change in background stream of repetitive syllables (/ra-la/). If contrast is perceived, they turn their head towards rewarding toy, if it is not perceived, they don’t.
 Japanese infants – At 6 – 8 months they turned their heads more than 50% of time; At 10 – 12 months there was a decrease in discrimination.
 American infants – At 6 – 8 months they turned their heads more than 50% of time; At 10 -12 months there was an increase in discrimination.

Question 4

Improvement in discrimination showed by 10-12 months can result from enhancement of general perceptual/attentional mechanisms taking place at that age.
 Evidence to support this hypothesis:

Answer 4

1. There are important developmental changes in maturation of central auditory system in first two years of life.
2. Infants were asked to look at attractive toy and this attentional network matures during this period (10-12 months).

Question 5

Results of ‘head turn’ reflect specific development of native-language categorical perception
Evidence:

Answer 5

 6 – 12 months – Very active period in language development.
 Infants are sensitive to patterns of variability within native-language phonetic categories – Helps building linguistic knowledge.
 Infants acquire different types of phonological knowledge that will lead to successful word segmentation.
 8 months – Repeatedly exposed to words starting with /p/ or /b/ were able to detect subtle variations within and between categories.
 10.5 months – Use within category distinctions to segment words and are sensitive to different pronunciations of a single phoneme.