University of Potsdam, Cognitive Sciences, Department of Linguistics, Karl-Liebknecht-Str. 24-25, D-14476 Potsdam, Germany.
University of Potsdam, Cognitive Sciences, Department of Linguistics, Karl-Liebknecht-Str. 24-25, D-14476 Potsdam, Germany.
Cognition. 2022 Jul;224:105054. doi: 10.1016/j.cognition.2022.105054. Epub 2022 Feb 22.
Young infants can segment continuous speech with statistical as well as prosodic cues. Understanding how these cues interact can be informative about how infants solve the segmentation problem. Here we investigate how German-speaking adults and 9-month-old German-learning infants weigh statistical and prosodic cues when segmenting continuous speech. We measured participants' pupil size while they were familiarized with a continuous speech stream where prosodic cues were pitted off against transitional probabilities. Adult participants' changes in pupil size synchronized with the occurrence of prosodic words during the familiarization and the temporal alignment of these pupillary changes was predictive of adult participants' performance at test. Further, 9-month-olds as a group failed to consistently segment the familiarization stream with prosodic or statistical cues. However, the variability in temporal alignment of the pupillary changes at word frequency showed that prosodic and statistical cues compete for dominance when segmenting continuous speech. A follow-up language development questionnaire at 40 months of age suggested that infants who entrained to prosodic words performed better on a vocabulary task and those infants who relied more on statistical cues performed better on grammatical tasks. Together these results suggest that statistics and prosody may serve different roles in speech segmentation in infancy.
婴幼儿可以使用统计和韵律线索来分割连续的语音。了解这些线索如何相互作用，可以为婴幼儿如何解决分割问题提供信息。在这里，我们研究了德语成年人和 9 个月大的德语学习婴儿在分割连续语音时如何权衡统计和韵律线索。我们在参与者熟悉连续语音流的过程中测量了他们的瞳孔大小，在这个过程中，韵律线索与过渡概率相抗衡。成年参与者的瞳孔大小变化与熟悉过程中韵律词的出现同步，这些瞳孔变化的时间对准可以预测成年参与者在测试中的表现。此外，9 个月大的婴儿作为一个群体，无法始终如一地使用韵律或统计线索来分割熟悉的语音流。然而，在词频时瞳孔变化的时间对准的可变性表明，在分割连续语音时，韵律和统计线索相互竞争主导地位。在 40 个月大时进行的后续语言发展问卷调查显示，与韵律词同步的婴儿在词汇任务上表现更好，而更多依赖统计线索的婴儿在语法任务上表现更好。这些结果表明，在婴儿期，统计信息和韵律可能在言语分割中发挥不同的作用。
