一項研究發(fā)現(xiàn)，在子宮內(nèi)聽到的聲音可能塑造發(fā)育中的人類大腦,，從而影響人出生后的語音和語言發(fā)育,。人類胎兒在懷孕后大約27周開始感受到外部聲音,，引發(fā)胎兒聽覺皮層重新組織以及正在發(fā)育的神經(jīng)系統(tǒng)的成熟,。但是胎兒是否能夠?qū)W習這些聲音從而影響在嬰兒期的語音感受和發(fā)育，這仍然不清楚,。Eino Partanen及其同事探索了胎兒期的經(jīng)歷如何影響胎兒進行學(xué)習的神經(jīng)基礎(chǔ)的,，而該學(xué)記過程會響應(yīng)胎兒在子宮內(nèi)聽到的聲音。這組作者對33名芬蘭女性從懷孕第29周直到出生進行了跟蹤,。其中半數(shù)母親每周聆聽幾次重復(fù)數(shù)百遍的假詞“tatata”的簡短錄音,，有時候中間那個音節(jié)被替換為“to”或者以不同的音調(diào)發(fā)出。在出生后,，比較了在子宮中曾經(jīng)接觸過這些發(fā)音和沒有接觸過這些發(fā)音的新生兒對這個假詞以及不熟悉的發(fā)音變化的神經(jīng)響應(yīng),。這些發(fā)現(xiàn)提示胎兒的大腦具有在出生前進行聽覺學(xué)習的能力，并且出現(xiàn)了結(jié)構(gòu)變化,，導(dǎo)致了可能在嬰兒期影響語言習得的神經(jīng)記憶蹤跡,。這組作者說，這些發(fā)現(xiàn)可能為著眼于預(yù)防未來的語言障礙或幫助緩解誦讀困難等遺傳疾病的干預(yù)手段提供信息,。（生物谷 Bioon.com）
生物谷推薦的英文摘要
PNAS doi: 10.1073/pnas.1302159110
Learning-induced neural plasticity of speech processing before birth
Eino Partanena,b,1, Teija Kujalaa,c, Risto Näätänena,d,e, Auli Liitolaa, Anke Sambethf, and Minna Huotilainena,b,g
Learning, the foundation of adaptive and intelligent behavior, is based on plastic changes in neural assemblies, reflected by the modulation of electric brain responses. In infancy, auditory learning implicates the formation and strengthening of neural long-term memory traces, improving discrimination skills, in particular those forming the prerequisites for speech perception and understanding. Although previous behavioral observations show that newborns react differentially to unfamiliar sounds vs. familiar sound material that they were exposed to as fetuses, the neural basis of fetal learning has not thus far been investigated. Here we demonstrate direct neural correlates of human fetal learning of speech-like auditory stimuli. We presented variants of words to fetuses; unlike infants with no exposure to these stimuli, the exposed fetuses showed enhanced brain activity (mismatch responses) in response to pitch changes for the trained variants after birth. Furthermore, a significant correlation existed between the amount of prenatal exposure and brain activity, with greater activity being associated with a higher amount of prenatal speech exposure. Moreover, the learning effect was generalized to other types of similar speech sounds not included in the training material. Consequently, our results indicate neural commitment specifically tuned to the speech features heard before birth and their memory representations.
