Article

Healthy adults can identify spoken words at a remarkable speed, by incrementally
analyzing word-onset information. It is currently unknown how this adult-level
speed of spoken-word processing emerges during children's native-language
acquisition. In a picture-word mismatch paradigm, we manipulated the semantic
congruency between picture contexts and spoken words, and recorded event-related
potential (ERP) responses to the words. Previous similar studies focused on the
N400 response, but we focused instead on the onsets of semantic congruency
effects (N200 or Phonological Mismatch Negativity), which contain critical
information for incremental spoken-word processing. We analyzed ERPs obtained
longitudinally from two age cohorts of 40 primary-school children (total n=80) in
a 3-year period. Children first tested at 7 years of age showed earlier onsets of
congruency effects (by approximately 70ms) when tested 2 years later (i.e., at
age 9). Children first tested at 9 years of age did not show such shortening of
onset latencies 2 years later (i.e., at age 11). Overall, children's onset
latencies at age 9 appeared similar to those of adults. These data challenge the
previous hypothesis that word processing is well established at age 7. Instead
they support the view that the acceleration of spoken-word processing continues
beyond age 7.
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Langue : ANGLAIS