The Influence of Maternal Input on the Early Acquisition of Japanese Vocabulary in comparison to English

自从Gentner(1982)声称名词在儿童早期词汇中普遍占优势以来，英语儿童的名词偏向得到了证实，而汉语和韩语中动词的盛行也被报道了。解释指出了诸如PRO-DROP这样的语言类型学因素，这促进了以动词为中心的输入。对于意大利语和日语，都是支持Drop的语言，报告的结果喜忧参半。一种可能的解释是，支持丢弃的语言允许母亲言语中更大的个体差异，这反过来又导致个体孩子的一系列不同的词汇构成。我们对4个日语母子二元组的纵向语音数据的研究结果表明，母亲对孩子的语音进行了调整，并采用了更侧重于名词的语体。这种调整的程度各不相同，而且似乎与儿童的词汇构成有关。母亲以名词和宾语为中心的言语风格(在类型、记号和孤立的词语呈现、高频率的对象描述)的儿童表现出偏名性词汇，而母亲使用名词和动词更均衡的儿童产生平衡的或略偏向动词的词汇。我们的结果表明，与一般语言类型相比，个体母亲的输入在儿童名词偏向的发展中起着更重要的作用。

Since Gentner's (1982) claim that nouns are universally predominant in children's early vocabulary, a noun bias has been confirmed in English-speaking children, while for Mandarin and Korean a prevalence of verbs has been reported. Explanations point to such language-typological factors as pro-drop, which promotes a verb-focused input. For Italian and Japanese, both pro-drop languages, mixed results are reported. On possible explanation is that pro-drop languages allow for greater individual variation in maternal speech, which in turn results in a range of different vocabulary compositions in individual children. Our results from longitudinal speech data of 4 Japanese-speaking mother-child dyads indicate that the mothers adjusted their speech to their children, and adapted a more noun-focused style. This adjustment occurred to an individually different degree, and appeared to be connected with the children's vocabulary composition. The children whose mothers had a noun-and object-focused speech style (high noun/verb ratio in types, tokens, and isolated word presentation, high frequency of object descriptions) displayed a noun-biased vocabulary, while the children of mothers whose use of nouns and verbs was more balanced, produced a balanced or slightly verb-biased vocabulary. Our results suggest that the individual maternal input plays a more important role in a child's development of a noun bias than the general language type.