Infant attention to facial expressions and facial motion

Three-month-old infants were shown moving faces and still faces on videotape in a paired-comparison situation. Motion type was clearly specified, and facial expression and motion were separately varied. Infants saw a still face, internal motion on the face (i.e., motion of the internal features), and whole object (i.e., side-to-side) motion, each with happy and neutral expressions. Infants showed preference for expressions when the face was still and when it showed internal motion. Facial expression and facial motion were equally preferred, and both appeared to be salient dimensions of the face for three-month-old infants.