Smiling and fussing in seven-month-old preterm and full-term black infants in the still-face situation

We investigated emotional responses to the still-face paradigm in 7-month-old preterm and full-term black infants. Baby FACS criteria were used to code the duration and intensity of infant smiles and the presence or absence of cry faces and fussy vocalizations within each episode. Infants in both groups showed the still-face effect: a significant reduction in smiling from episode 1 (baseline) to episode 2 (maternal still-face) and partial return to baseline in episode 3 (recovery). A multivariate analysis of covariance (MANCOVA) for big smiles yielded significant main effects for group and episode and a significant group x episode interaction. Preterm infants spent less time than full-term infants displaying big smiles in episode 1 and a less pronounced decrease in big smiles in episode 2. Maternal depressive symptoms did not differ significantly between groups. Counter to our expectations, depressive symptoms were positively associated with small-to-medium smiles in the baseline episode but not with big smiles in any episode. These findings confirm the robustness of the still-face paradigm and its potential usefulness for research on individual as well as group differences in affective communication in infants.