| Popis: |
Infants start to show signs of speech-perceptual attunement, that is, specialization for consonants in their native language, around 10-months of age. The current project investigatedthe role played by speech-auditory mechanisms in this early speech perceptual phenomenon.Using a psychoacoustic approach combined with electrophysiology, we explored the neuralunderpinnings of key acoustic components of speech: amplitude and frequency modulations(AM/FM). Cortical auditory evoked potentials (CAEPs) were measured for native (voiced/b/ and unvoiced unaspirated /p/) and non-native (unvoiced aspirated English /pʰ/) consonants in French-learning 6-month-old, 10-month-old and French adult listeners. Threeacoustically manipulated conditions were designed to selectively preserve : 1) original FMand AM, 2) original AM only, and 3) the slowest AM (< 8 Hz) only. Consistent withprevious behavioral studies, 10-month-old and adult CAEPs show similar patterns, both ofwhich differ from those of 6-month-olds. These results suggest that neural speech-auditorymechanisms evolve during perceptual attunement. |
