Centers & Labs

RIKEN Brain Science Institute

Laboratory for Language Development

Laboratory Head: Reiko Mazuka (Ph.D.)
Reiko  Mazuka(Ph.D.)

We investigate how young infants become interested in speech that surround them, and learn to be the speaker of that language. In particular, we focus on the role of 'prosody' (i.e., intonation, rhythm and other suprasegmental characteristics of the speech) in language acquisition. We study how infants become attuned to the prosodic characteristics of their ambient language, and how acquiring it would affect other domains of language development.

Main Research Field

Psychology & Psychiatry

Related Research Fields

Neuroscience & Behavior / Multidisciplinary

Research Subjects

  • Acquisition of language specific phonology and prosody by Japanese infants
  • Phonetic and prosodic characteristics of Japanese infant directed speech
  • Contribution of linguistic information and cognitive development in children's language comprehension
  • Role of sound-character relationship in learning how to read in Japanese
  • Computational modeling of phonological acquisition

Selected Publications

  1. Tsuji, S, Fikkert P, Yamane N, and Mazuka R.:
    "Language-general biases and language-specific experience contribute to phonological detail in toddlers' word representations"
    Developmental Psychology , (in press)
  2. Mazuka R, Igarashi Y, Martin A, and Utsugi A.:
    "Infant-directed speech as a window into the dynamic nature of phonology"
    Laboratory Phonology, 6(3-4), 281-303 (2015)
  3. Hawthorne K, Mazuka R, and Gerken L.:
    "The acoustic salience of prosody trumps infants' acquired knowledge of language-specific prosodic patterns"
    Journal of Memory and Language, 82, 105-117 (2015)
  4. Mazuka R.:
    "Learning to become a native listener of Japanese"
    In M. Nakayama (Ed.), Handbook of Japanese Psycholinguistics, Chapter 2, 19-47 (2015)
  5. Arai M, Nakamura C, and Mazuka R.:
    "Predicting the unbeaten path through syntactic context"
    Journal of Experimental Psychology:Learning, Memory and Cognition, 41(2), 482-500 (2015)
  6. Martin A, Schatz T, Versteegh M, Dupoux E, Mazuka R, Miyazawa K, and and Cristia A.:
    "Mothers speak less clearly to infants: A comprehensive test of the hyperarticulation hypothesis"
    Psychological Science, 26(3), 341-347 (2015)
  7. Tsuji S, Mazuka R, Cristia A, and Fikkert P.:
    "Even at 4 months, a labial is a good enough coronal, but not vice versa"
    Cognition, 134(2015), 252-256 (2015)
  8. Hirose Y, and Mazuka R.:
    "Predictive processing of novel compounds: Evidence from Japanese"
    Cognition(2015), 350-358 (2014)
  9. Matsuda YT, Ueno K, Cheng K, Konishi Y, Mazuka R, and Okanoya K.:
    "Auditory observation of infant-directed speech by mothers: experience-dependent interaction between language and emotion in the basal ganglia."
    Frontiers in Human Neuroscience, 8, 907 (2014)
  10. Martin A, Utsugi A, and Mazuka R.:
    "The multidimensional nature of hyperspeech: Evidence from Japanese vowel devoicing."
    Cognition, 132(2), 216-228 (2014)

Lab Members

Principal Investigator

Reiko Mazuka
Laboratory Head

Core Members

Yoritaka Akimoto
Research Scientist
Naoto Yamane
Research Specialist
Miki Takahasi
Visiting Researcher
Yuri Hatano
Technical Staff II
Naoko Kijima
Technical Staff II
Natsumi Shibata
Technical Staff II
Ying Deng
Technical Staff Ⅱ

Contact information

2-1 Hirosawa, Wako, Saitama 351-0198, Japan

Email: mazuka [at]

Related links

Recent research results

January 29, 2015: Press Release
Mothers don't speak so clearly to their babies