play behaviour in juveniles, and the mother-infant interaction in pre-weaniling rats. The
major finding is that USVs in infants and adults are different. It is hypothesized that there
should be a transition in vocal communication that parallels the transition from infancy to
adulthood, that parallels the development of their social autonomy. The method used in the
present experiments was a whole litter recording technique in which vocalizations were …