Abstract：
Infant-directed speech (IDS) is known to be characterised by phonetic and prosodic cues along with reduced vocabulary and syntax compared to adult-directed speech (ADS). However, there is considerable variation between mothers in the degree of lexical and syntactic reduction of their IDS. The present study aims to investigate the correspondences of the inter-individual variation of maternal IDS at 6 and 18 months with infants\' language development at 18 months. 109 dyads of mothers and their firstborn infants participated in the study. Mothers\' ID and AD storytelling based on standard picture stimuli were recorded at 6 and 18 months of their infants\' age. We analysed measures of speech quantity (number of utterances and words), syntactic complexity (mean length of utterance), and lexical diversity (type-token ratio). Language growth was measured bimonthly using the Hungarian adaptation of the MacArthur-Bates CDI W&G form. The results did not reveal any association between characteristics of mothers\' ID narratives and their infants\' concurrent language skills at 18 months. However, we found a longitudinal link between a distinct pattern of linguistic simplification in maternal ID storytelling at 6 months and the development of expressive vocabulary in infants at 18 months. Infants whose mother tends to reduce both lexical and syntactic complexity of ID narratives the most are more likely to exhibit higher language outcomes. Further research is warranted to explore the background factors and longer-term effects of this maternal strategy.
摘要：
与成人定向语音（ADS）相比，婴儿定向语音（IDS）的特征在于语音和韵律提示以及减少的词汇和语法。然而,母亲在IDS的词汇和句法减少程度上存在相当大的差异。本研究旨在调查6个月和18个月时母体IDS与18个月时婴儿语言发育的个体差异。109位母亲及其长子婴儿参加了这项研究。母亲在婴儿年龄的6个月和18个月时记录了基于标准图片刺激的ID和AD讲故事。我们分析了语音量的测量(话语和单词的数量)，句法复杂性(平均语长)，和词汇多样性(类型标记比)。使用匈牙利改编的MacArthur-BatesCDIW＆G形式，每两个月测量一次语言的增长。结果没有揭示母亲的ID叙述特征与18个月时婴儿的并发语言技能之间的任何关联。然而,我们发现,在6个月时母亲ID讲故事的语言简化的独特模式与18个月时婴儿表达性词汇的发展之间存在纵向联系.母亲最倾向于降低ID叙述的词汇和句法复杂性的婴儿更有可能表现出更高的语言结果。需要进一步的研究来探索这种母亲策略的背景因素和长期影响。
