Krueger Charlene, Garvan Cynthia
University of Florida, Gainesville, FL, United States.
University of Florida, Gainesville, FL, United States.
Infant Behav Dev. 2014 May;37(2):162-73. doi: 10.1016/j.infbeh.2013.12.007. Epub 2014 Feb 16.
Prior research has demonstrated that the late-term fetus is capable of learning and then remembering a passage of speech for several days, but there are no data to describe the earliest emergence of learning a passage of speech, and thus, how long that learning could be remembered before birth. This study investigated these questions. Pregnant women began reciting or speaking a passage out loud (either Rhyme A or Rhyme B) when their fetuses were 28 weeks gestational age (GA) and continued to do so until their fetuses reached 34 weeks of age, at which time the recitations stopped. Fetuses' learning and memory of their rhyme were assessed at 28, 32, 33, 34, 36 and 38 weeks. The criterion for learning and memory was the occurrence of a stimulus-elicited heart rate deceleration following onset of a recording of the passage spoken by a female stranger. Detection of a sustained heart rate deceleration began to emerge by 34 weeks GA and was statistically evident at 38 weeks GA. Thus, fetuses begin to show evidence of learning by 34 weeks GA and, without any further exposure to it, are capable of remembering until just prior to birth. Further study using dose-response curves is needed in order to more fully understand how ongoing experience, in the context of ongoing development in the last trimester of pregnancy, affects learning and memory.
先前的研究表明，晚期胎儿能够学习并记住一段语音长达数天，但尚无数据描述最早出现学习一段语音的时间，以及在出生前这种学习能被记住多久。本研究对这些问题进行了调查。孕妇在胎儿孕龄（GA）28周时开始大声背诵或朗读一段文字（韵律A或韵律B），并持续进行，直到胎儿达到34周龄，此时背诵停止。在28、32、33、34、36和38周时评估胎儿对其韵律的学习和记忆。学习和记忆的标准是在一名女性陌生人朗读这段文字的录音开始后出现刺激诱发的心率减速。在孕龄34周时开始出现持续心率减速的检测，在孕龄38周时具有统计学显著性。因此，胎儿在孕龄34周时开始表现出学习的证据，并且在没有任何进一步接触的情况下，能够记住直到出生前。需要使用剂量反应曲线进行进一步研究，以便更全面地了解在妊娠晚期持续发育的背景下，持续的体验如何影响学习和记忆。
