title: "Mom called me!" Behavioral and prefrontal responses of infants to self-names spoken by their mothers.
abstract: Development of a sense of self is a fundamental process needed for human social interaction. Although functional neuroimaging studies have revealed the importance of medial prefrontal cortex (mPFC) in self-referencing, how this function develops in infancy remains poorly understood. To determine the cerebral basis underlying processing of self-related stimuli, we used behavioral measures and functional multi-channel near-infrared spectroscopy (fNIRS) to measure prefrontal cortical responses in 6-month-old infants hearing their own names. We also investigated the influence of a mother's voice on name perception in infants - an ability that plays a crucial role in the recognition of social signals. Experiment 1 measured the behavioral preferences of infants for their own names and for other names, spoken either by their mothers or by strangers. Results showed that infants significantly preferred their own name to other names, regardless of speaker type. Experiment 2 examined hemodynamic responses to the same four conditions in the prefrontal cortex. Compared with other names, hearing their own names, especially when spoken by their mother, elicited greater activity in the infant's dorsal mPFC. Furthermore, the magnitude of the cerebral response correlated with the degree of behavioral preference only when involving their mother's voice. These findings suggest that, particularly in the context of their mothers' voice, the dorsal mPFC of infants is already sensitive to social signals related to self at 6 months. At the same time, familiarity and affection related processing are also discussed as possible factors modulating dorsal mPFC activation at this age.
authors.affiliation: Department of Psychology, Faculty of Letters, Keio University, 2-15-45 Mita, Minato-ku, Tokyo 108-8345, Japan; Graduate School of Education, Kyoto University, Yoshida-honmachi, Sakyo-ku, Kyoto 606-8501, Japan.
authors.forename: Masahiro
authors.initials: M
authors.lastname: Imafuku
authors.affiliation: Department of Psychology, Faculty of Letters, Keio University, 2-15-45 Mita, Minato-ku, Tokyo 108-8345, Japan.
authors.forename: Yoko
authors.initials: Y
authors.lastname: Hakuno
authors.affiliation: Graduate School of Human Relations, Keio University, 2-15-45 Mita, Minato-ku, Tokyo 108-8345, Japan.
authors.forename: Mariko
authors.initials: M
authors.lastname: Uchida-Ota
authors.affiliation: Department of Psychology, Faculty of Letters, Keio University, 2-15-45 Mita, Minato-ku, Tokyo 108-8345, Japan.
authors.forename: Jun-Ichi
authors.initials: JI
authors.lastname: Yamamoto
authors.affiliation: Department of Psychology, Faculty of Letters, Keio University, 2-15-45 Mita, Minato-ku, Tokyo 108-8345, Japan; Institut d'étude de la cognition, Ecole Normale Supérieure, 29, rue d'Ulm, 75005 Paris, France. Electronic address: myasuyo@bea.hi-ho.ne.jp.
authors.forename: Yasuyo
authors.initials: Y
authors.lastname: Minagawa
mesh_terms: D001307:Auditory Perception / Q000502:physiology*; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D009034:Mother-Child Relations; D017397:Prefrontal Cortex / Q000502:physiology*; D021641:Recognition, Psychology / Q000502:physiology*; D012649:Self Concept; D012815:Signal Processing, Computer-Assisted; D019265:Spectroscopy, Near-Infrared
keywords: Infants; Mother's voice; Near-infrared spectroscopy; Self-name; The medial prefrontal cortex (mPFC)