The effect of manipulating maternal behavior during an interaction on three- and six-month-olds' affect and attention.

3 studies were designed to examine the "still-face" paradigm, in which mothers stared at their 3- or 6-month-olds for a brief, still-face period interposed between 2 periods of normal face-to-face interaction. 6-month-olds decreased smiling and gazing at their mothers and grimaced more during the still-face period relative to the other periods; no period effects occurred in a no-change control group (Studies 1 and 2). Similar results were obtained when mothers and their infants observed and interacted with each other over closed-circuit color television monitors (Study 3). Moreover, the same relative decline in the infants' visual attention and positive affect during the still-face period occurred to a change in mothers' facial display (a televised, prerecorded, still face vs. a televised, live, interacting face) regardless of the presence or absence of their interactive voices (sound on the infants' monitor turned on or off). 3-month-olds exhibited a significant still-face effect, but only when maternal touch was a part of the manipulation (Study 1 vs. 2); therefore, the televised procedure was not conducted. The still-face effect is a robust phenomenon, produced with either "live" or "televised" procedures, both of which offer promising techniques for examining models of socioemotional perception/understanding of infants.