A longitudinal study for the individual differences in phonetic discrimination in infancy and language development in childhood.

• Project/Area Number: 19K02636
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 09030:Childhood and nursery/pre-school education-related
• Research Institution: Institute of Physical and Chemical Research
• Principal Investigator: Yamane Naoto 国立研究開発法人理化学研究所, 脳神経科学研究センター, 専門職研究員 (60550192)
• Project Period (FY): 2019-04-01 – 2023-03-31
• Project Status: Completed (Fiscal Year 2022)
• Budget Amount: ¥4,420,000 (Direct Cost: ¥3,400,000、Indirect Cost: ¥1,020,000); Fiscal Year 2022: ¥650,000 (Direct Cost: ¥500,000、Indirect Cost: ¥150,000); Fiscal Year 2021: ¥1,170,000 (Direct Cost: ¥900,000、Indirect Cost: ¥270,000); Fiscal Year 2020: ¥1,040,000 (Direct Cost: ¥800,000、Indirect Cost: ¥240,000); Fiscal Year 2019: ¥1,560,000 (Direct Cost: ¥1,200,000、Indirect Cost: ¥360,000)
• Keywords: 乳幼児 / 言語発達 / 個人差 / 音韻弁別能力 / 縦断研究 / 乳児

Outline of Research at the Start

ヒトの言語獲得において、乳児期の母語音声に対する聴覚学習はその基盤をなしている。ではこの乳児期の聴覚情報処理の個人差は、その後の言語発達やコミュニケーション能力の発達においてどの程度また、どのように関係しているのだろうか？本研究では、言語発達の初期段階に見られる音韻弁別能力の個人差を生む要因の詳細な検討と、幼児期の言語運用・コミュニケーション能力の測定を通して、月齢縦断的に両者の関係性の解明を目指す。

Outline of Final Research Achievements

Measuring and understanding language skills at the early stage of life is important as it is the foundation for later language development. In the present study, we report results of a large scale study with Japanese infants that investigated whether infants’ family environment　impact infants’ vocabulary size at 20-month of age. The results revealed that　the vocabulary size of infants whose mother worked, or on maternal leave from their work was larger than infants whose mothers were no-worker. In contrast, household income, age and years of education of parents and interaction were not significant. These results suggested that Japanese infants’ vocabulary at 20 month is not impacted by SES, a sharp contrast to American infants. Current findings indicate that the predictor of infants’ vocabulary size by home environment at this age was not universal but culturally or linguistically different.

Academic Significance and Societal Importance of the Research Achievements

本研究では発達早期の乳児の音韻弁別能力の個人差とその後の獲得語彙との相関関係、またそれらに与える家庭環境の検討を日本語学習環境にある親子を対象に大規模データから検討した。これらの結果から、乳児の音声知覚能力の個人差の存在とそれに与える家庭環境の影響を明らかにした。これまでに、乳児期の音韻弁別能力の個人差自体の検討に焦点を当てた研究は国内外を通し見当たらず、本研究で得られたデータは単に言語発達に関する研究としてだけではなく、子供の発達全般にかかわる貴重な研究資料となり得、教育・福祉分野などにおける貢献が見込まれる。

Research Products

• [Journal Article] Developmental differences in the hemodynamic response to changes in lyrics and melodies by 4- and 12-month-old infants (2021)
  • Author(s): Yamane Naoto、Sato Yutaka、Shimura Yoko、Mazuka Reiko
  • Journal Title: Cognition Volume: - Pages: 104711-104711
  • DOI: 10.1016/j.cognition.2021.104711
  • Peer Reviewed
• [Presentation] 歌の脳内処理の発達的変化とその臨床応用の可能性 (2022)
  • Author(s): 山根直人
  • Organizer: 日本赤ちゃん学会第22回学術集会
• [Presentation] communicative functions of singing to infants: Visual fixation and pupil dilation provide complementary results. (2022)
  • Author(s): Naoto Yamane, Ako Ohori, Reiko Mazuka
  • Organizer: The 2022 International Conference on Infant Studies
  • Int'l Joint Research
• [Presentation] Not all /r/ and /l/ are difficult to discriminate for Japanese infants: Japanese infants' discrimination of Mongolian /r/ and /l/. (2022)
  • Author(s): Rongna A, Naoto Yamane, Reiko Mazuka
  • Organizer: The 47th Annual Boston University Conference on Language Development
  • Int'l Joint Research
• [Presentation] 歌い手への選好から見る歌いかけのコミュニケーション機能 (2021)
  • Author(s): 山根直人・大堀綾子・馬塚れい子
  • Organizer: 日本赤ちゃん学会第21回学術集会
• [Presentation] ストレス下における情動表出と生理指標の応答はなぜ一致しないのか：10カ月児の母子分離に対するストレス応答反応の検討 (2021)
  • Author(s): 高橋美樹・福田早苗・山根直人・馬塚れい子
  • Organizer: 日本赤ちゃん学会第21回学術集会
• [Presentation] Discrimination of /p/-/ph/ stop contrast in early speech perception of Thai infants. (2020)
  • Author(s): Chutamanee Onsuwan, Nawasri Chonmahatrakul, Juthatip Duangmal, Naoto Yamane, Hyun Kyung Hwang, and Reiko Mazuka
  • Organizer: The XXII vICIS.
  • Int'l Joint Research
• [Presentation] Infants’ preference for singers: Effect of singer’s behavior and styles. (2020)
  • Author(s): Naoto Yamane, Ako Ohori, and Reiko Mazuka
  • Organizer: The XXII vICIS.
  • Int'l Joint Research
• [Presentation] Parents’ income and education do not impact Japanese infants’ vocabulary at 20 months. (2020)
  • Author(s): Naoto Yamane, Miki Takahasi, Natsumi Shibata, Ying Deng and Reiko Mazuka
  • Organizer: The XXII vICIS.
  • Int'l Joint Research
• [Presentation] IDS properties that are rare in adult language can contribute significantly to language development: An fNIRS study on infant-directed vocabulary (IDV) in Japanese (2020)
  • Author(s): Yoritaka Akimoto, Miki Takahasi, Naoto Yamane, Akiko Hayashi, Reiko Mazuka.
  • Organizer: The XXII vICIS.
  • Int'l Joint Research
• [Presentation] Factors associated with separation-induced infant cortisol reactivity in a large sample study (2020)
  • Author(s): Sanae Fukuda, Miki Takahashi, Naoto Yamane and Reiko Mazuka
  • Organizer: The XXII vICIS.
  • Int'l Joint Research
• [Presentation] Japanese-learning infants' discrimination of Japanese and Thai stop contrasts. (2020)
  • Author(s): Reiko Mazuka, Hyun Kyung Hwang, Naoto Yamane, and Mieko Takada
  • Organizer: The XXII vICIS.
  • Int'l Joint Research
• [Presentation] KOREAN MOTHERS’PRODUCTION OF LARYNGEAL STOPS TO THEIR INFANTS AS COMPARED WITH ADULTS IN THE CONTEXT OF TONOGENESIS. (2019)
  • Author(s): Choi, Y., Nam, M., Mazuka, R., Hwang, H. K., & Yamane, N.
  • Organizer: the 19th International Congress of Phonetic Sciences.
  • Int'l Joint Research
• [Presentation] STABILITY OF ACOUSTIC CUES OF THE THREE-WAY VOICING CONTRAST IN THAI MOTHERS’STOP PRODUCTION. (2019)
  • Author(s): Onsuwan, C., Duangmal, J., Chonmahatrakul, N., Yamane, N., Hwang, H. K., & Mazuka, R.
  • Organizer: the 19th International Congress of Phonetic Sciences.
  • Int'l Joint Research