Weighting of amplitude and formant rise time cues by school-aged children : a mismatch negativity study

Purpose: An important skill in the development of speech perception is to apply optimal weights to acoustic cues so that phonemic information is recovered from speech with minimum effort. Here, we investigated the development of acoustic cue weighting of amplitude rise time (ART) and formant rise time (FRT) cues in children as measured by mismatch negativity (MMN). Method: Twelve adults and 36 children aged 6-12 years listened to a/ba/-/wa/ contrast in an oddball paradigm in which the standard stimulus had the ART and FRT cues of/ba/. In different blocks, the deviant stimulus had either the ART or FRT cues of/wa/. Results: The results revealed that children younger than 10 years were sensitive to both ART and FRT cues whereas 10- to 12-year-old children and adults were sensitive only to FRT cues. Moreover, children younger than 10 years generated a positive mismatch response, whereas older children and adults generated MMN. Conclusion: These results suggest that preattentive adultlike weighting of ART and FRT cues is attained only by 10 years of age and accompanies the change from mismatch response to the more mature MMN response.