Cognitive Neuroscience Sector, Scuola Internazionale Superiore di Studi Avanzati, Trieste 34014, Italy.
Proc Natl Acad Sci U S A. 2010 Feb 23;107(8):3823-8. doi: 10.1073/pnas.0914326107. Epub 2010 Feb 2.
We tested healthy preterm (born near 28 +/- 2 weeks of gestational age) and full-term infants at various different ages. We compared the two populations on the development of a language acquisition landmark, namely, the ability to distinguish the native language from a rhythmically similar one. This ability is attained 4 months after birth in healthy full-term infants. We measured the induced gamma-band power associated with passive listening to (i) the infants' native language (Spanish), (ii) a rhythmically close language (Italian), and (iii) a rhythmically distant language (Japanese) as a marker of gains in language discrimination. Preterm and full-term infants were matched for neural maturation and duration of exposure to broadcast speech. We found that both full-term and preterm infants only display a response to native speech near 6 months after their term age. Neural maturation seems to constrain advances in speech discrimination at early stages of language acquisition.
我们在不同时期测试了健康的早产儿（接近 28+/-2 周的胎龄出生）和足月婴儿。我们比较了这两个群体在语言习得里程碑上的发展情况，即区分母语和节奏相似的语言的能力。这种能力在健康足月婴儿出生后 4 个月就会获得。我们测量了与被动聆听相关的诱导伽马频带功率，（i）婴儿的母语（西班牙语），（ii）节奏相近的语言（意大利语），以及（iii）节奏较远的语言（日语），作为语言辨别力提高的标志。早产儿和足月婴儿在神经成熟和广播语音暴露时间方面相匹配。我们发现，只有足月和早产儿在接近他们的足月年龄后 6 个月才对母语有反应。神经成熟似乎限制了语言习得早期阶段的言语辨别能力的提高。
