| Infants learn about the world in the context of social-communicative signals. Motivated by recent evidence that language shapes infants' learning, my goal is to characterize the cognitive mechanisms linking communication, language and cognition in infancy. In Chapters I and II, I explore the breadth of signals that promote 6-month-olds' object categorization. These studies reveal that 6-month-olds flexibly identify novel communicative signals in their environment and that, once identified, these signals promote their object categorization in a manner distinguishable from language. In Chapters III-V, I go on to consider the breadth of learning mechanisms influenced by communicative and linguistic signals from 3-9 months of age. These results document that, by 7 months, auditory abstract rule learning is -- like categorization -- broadly promoted by communicative signals, even those to which infants are just introduced. In contrast, visual abstract rule learning (at 3-4 months) and object identification (at 8-9 months) appear to proceed independently of language. These findings offer new insights into what it takes for a signal to link to infants' cognition. They also place critical limits on the breadth of the mechanisms facilitated by communication, laying a foundation for future research to better understand how interactions between infants' social, language, and cognitive development shape their conceptual landscapes. |
