Our brains actually combine the sights, sounds, touches, smells into unitary events.

In addition to that, in our lab, we recently discovered that babies can perceive the faces and vocalizations of other species as unitary.

Now, the human mind is not a single unitary information processor, but it has a lot of different, special, evolved modules that do specific things for us.

We also happened to know that both adults and babies as well are able to perceive others as unitary events, that is to say, that baby, when that baby is interacting with that person, for that baby, that's mom.