本研究では前言語期から文法出現期の9ヶ月から24ヶ月児の母子の遊び場面の観察録画データから、第一に、母親の事物をあらわす育児語と動作をあらわす育児語の特徴を音韻面と形態統語情報から明らかにし、子どもの年齢による育児語使用に違いがあるか否か検討した。育児語の特徴は、事物育児語、動作育児語とも特殊モーラを含む語や自立モーラの反復が大部分であった。形態統語情報については、事物育児語は格助詞を伴うあるいは格助詞の省略された育児語が単独の事物育児語より多く発せられていた。動作育児語は「する」の動詞や動作誘発助詞を伴っていた。事物育児語、動作育児語とも子ども年齢で有意差はなかった。第二に、養育者は成人語と育児語で子どもに働きかけていることから、事物語と動作語の育児語率（育児語／（育児語+成人語））がその後（33ヶ月）の子どもの幼児語、成人語の事物語、動作語獲得へ及ぼす効果と効果をおよぼす月齢について検討した。その結果、14ヶ月児の母の事物育児語率タイプ、トークンは、33ヶ月事物成人語獲得に正の効果を、また、14ヶ月児の母親の動作育児語率トークンが33ヶ月動作幼児語に正の効果を及ぼしていた。一方、24ヶ月児の母親の動作育児語率は33ヶ月の動作幼児語、動作成人語に負の効果を及ぼしていた。母親の育児語の言語入力の効果は事物語、動作語で異なり、また、子どもの年齢においても異なっていた。

In this study, the effects of information resources on pragmatic reasoning were examined by controlling the speaker’s pointing gesture and gaze direction as nonlinguistic information, and object figures features such as shape, color, and marks. The experimenter either did or did not point to the monitor displaying three figure illustrations. Moreover, the experimenter’s gaze was either directed toward the participant or the monitor showing the stimulus. The result proved neither pointing nor gaze as effective in this experiment. Two reasons for this might be: 1) The participants could pay attention to the monitor anyway without non-linguistic cues. 2) The gaze cue might be relatively weak. However, it was also found that the participants used pragmatic reasoning better than chance level if the experimenter used pointing, suggesting that pointing is not entirely irrelevant. Further study is needed to explore the effect of non-linguistic information when people use pragmatic reasoning.

Bilingual language switching and its link to domain-general executive functions have been studied in the domain of language production, but they are seldom examined from the perspective of language comprehension. This study examined language switching using a language comprehension paradigm, and further discussed the role of working memory and inhibitory control associated with language switching in the paradigm. We focused on Japanese learners of English. In terms of response time, switching costs were not observed when leaners read a pair of two semantically related sentences presented in different languages (i.e., inter-sentential switching). Nevertheless, in such inter-sentimental switching trials, response time was positively correlated with the learners’ inhibitory control abilities when switching occurs from L2 to L1. In the opposite switching direction (i.e., from L1 to L2), on the other hand, response time was negatively correlated with their working memory capacity. Our results indicated that in comprehension, domain-general executive functions (working memory and inhibitory control) are differently associated depending on the direction of language switching.