Baby's Brain in Week 18
Babies like it when their senses are synchronized, rather than discordant. Even at one month, your child was able to match what she felt in her mouth to what she saw in front of her—remember the smooth and bumpy pacifier experiment? And now around this age, Baby will seek out sensory experiences that mesh with one another, such as touch with sight and movement with sound.
But it's difficult for babies to sort out a bombardment of sensory stimulation from their environment. Think about your last family gathering: With people talking, music blaring, and older kids running around, chances are Baby turned cranky pretty quickly. If Grandpa then bounced his grandbaby on his knee while singing a nursery rhyme, magically Baby was content again. Infants seems to love the up-and-down movement that matches a rhyme's sound, whether it's Hey Diddle Diddle, Jack and Jill, Humpty Dumpty, or that song you made up about your baby's chubby legs. It's synchronized sensory events your child seeks, and here's how we know it.
What the Research Shows
In one clever study, experimenters showed four-month-old babies two films simultaneously with no sound: One featured a person playing peek-a-boo, the other showed a person rhythmically striking a tambourine and a wood block with a stick.
Then the researchers played the two films again, this time with one of the video's sound tracks playing. The infants either heard a person saying, "Hello Baby, peek-a-boo," or the sound of a stick striking the tambourine and block. Most of the babies in the study looked toward the video that played the appropriate accompanying sound, as if to say, "Yep, this sound goes with that action, all right!" This indicated to researchers how interested in and able infants are at coordinating sights and sounds, even at this young age.