Infant graphs show the association of automated measurements of smile strength, eye constriction, mouth opening, and rated positive emotion. Mother graphs show the association of automated measurements of smile strength, eye constriction, and rated positive emotion. Positive emotion is offset by three fifths of a second to account for rating lag.

a) The AAM is a mesh that tracks and separately models rigid head motion (e.g., yaw, pitch, and roll, visible in the upper left hand portion of the images) and non-rigid facial movement over time (left to right). b) In this output display, each partner's face is outlined to illustrate lip corner movement, mouth opening, the eyes, brows, and the edges of the lower face; these outlines are reproduced in iconic form to the right of each partner.

Tickling and smiling activity are plotted over seconds. Smiling activity is the mean of smile strength and eye constriction intensity. Correlations between infant and mother smiling activity for each segment of interaction are displayed below that segment. Above each segment of interaction is a plot of the corresponding windowed cross-correlations between infant and mother smiling activity. As illustrated by the color bar to the right of the cross-correlation plots, high positive correlations are deep red, null correlations a pale green, and high negative correlations are deep blue. The horizontal midline of these plots indicates the zero-order correlation between infant and mother smiling activity. The correlations are calculated for successive three second segments of interaction. The plots also indicate the associations of one partner's current smiling activity with the successive activity of the other partner. Area above the midline indicates the correlation of current infant activity with successive lags of mother smiling activity. Area beneath the midline indicates the correlation of mother smiling activity with successive lags of infant smiling activity. Three lags of such activity are shown. For example, the area at the very bottom of a plot shows the correlation of a window of three seconds of current mother activity with a window of three seconds of infant activity that is to occur after three fifths of a second.