Five-month-old infants' vocalization when alone was investigated. Several researchers have reported observing that young infants vocalize in comfortable states without any response from others. As is implied by episodic reports in previous studies, it is possible that infants vocalize to play with their own vocal sound. Producing and listening to…

In a previous study, Adachi, Kuwahata, Fujita, Tomonaga & Matsuzawa demonstrated that infant Japanese macaques (Macaca fuscata) form cross-modal representations of conspecifics but not of humans. However, because the subjects in the experiment were raised in a large social group and had considerably less exposure to humans than to…

To learn relational terms such as verbs and prepositions, children must first dissect and process dynamic event components. This paper investigates the way in which 8- to 14-month-old English-reared infants notice the event components, "figure" (i.e., the moving entity) and "ground" (i.e., stationary setting), in both dynamic…

Patterns of developmental change in phonetic perception are critical to theory development. Many previous studies document a decline in nonnative phonetic perception between 6 and 12 months of age. However, much less experimental attention has been paid to developmental change in native-language phonetic perception over the same time period. We…