One experiment determined that the minimum angle at which infants can discriminate 2 sound presentations decreases substantially toward 48 weeks of age. In 3 succeeding experiments, infants aged 16, 20, and 28 weeks were able to discriminate sounds presented to each ear between 50 and 75 microseconds apart. (BC)

Presented five- and eight-month olds with silent moving and static video images of self, peer, and doll, and sounds of self and nonsocial objects. Found that recognition of one's image develops through experience with dynamic facial stimulation during first eight months. By five months, infants treat their faces and voices as familiar and social…