Infant sign language program effects on synchronic mother-infant interactions.

The effects of an intentional infant sign language program on mother-infant interactions were studied. Design was quasi-experimental, longitudinal, descriptive and comparative. The sample was composed of 14 mother-infant dyads, with the infants being between 5 and 9 months at the beginning of the study. The participants were middle or upper-middle socio-economic status. The interactions were evaluated through observations of free play and analyzed using a Grid to analyze early interactions. The frequency and duration of synchronic interactions were compared across experimental and control groups at 12-14 and 18-20 months of age using non-parametric Mann-Whitney tests. The results suggested significant differences between groups on visual and tactile synchronic interactions, and a tendency for vocal interactions, in the direction of higher frequencies in the experimental group.