title: Infant responses to maternal still-face at 4 and 9 months.
abstract: This study investigated developmental changes in infant responses to maternal still-face (SF) situations. Infants (21 males and 25 females) of Japanese mothers were observed in a face-to-face SF paradigm, comprising four phases (normal/SF/normal/SF), at two infant ages (4 and 9 months). The infants' facial expression, gaze direction, and vocalization were coded in both SF and normal interaction conditions. The results indicated that infants at both ages showed a decrease in displaying positive facial expression and gazing at their mothers during SF conditions. The 4-month-old displayed emotional expression and directed their gaze toward their mothers more frequently than the 9-month-old. However, the 9-month-old vocalized more often in SF situations, attempting to elicit responses from their mothers. The "carry-over" effect was observed only in 9-month-old. The results were discussed in the context of developmental changes in infants' social skills to cope with an emotionally stressful situation.
authors.affiliation: Ritsumeikan University, 56-1 Tojiin, Kitamach Kita-ku, Kyoto 603-8577, Japan. yato@lt.ritsumei.ac.jp
authors.forename: Yuko
authors.initials: Y
authors.lastname: Yato
authors.forename: Masatoshi
authors.initials: M
authors.lastname: Kawai
authors.forename: Koichi
authors.initials: K
authors.lastname: Negayama
authors.forename: Shunya
authors.initials: S
authors.lastname: Sogon
authors.forename: Kiyotaka
authors.initials: K
authors.lastname: Tomiwa
authors.forename: Hatsumi
authors.initials: H
authors.lastname: Yamamoto
mesh_terms: D000367:Age Factors; D005149:Facial Expression; D005260:Female; D006801:Humans; D007223:Infant; D018730:Infant Behavior / Q000502:physiology* / Q000523:psychology; D008137:Longitudinal Studies; D008297:Male; D008425:Maternal Behavior / Q000502:physiology* / Q000523:psychology; D009034:Mother-Child Relations; D011930:Reaction Time / Q000502:physiology*; D014705:Verbal Behavior / Q000502:physiology