How Infants Learn Word Meanings and Propositional Attitudes: A Neural Network Model

Abstract

An influential proposal by the developmental psychologist Michael Tomasello is that infants only properly begin learning word meanings when they acquire the concept of a communicative action, which happens around the age of 12 months. While Tomasello advances interesting empirical evidence for this proposal, he does not make any suggestions about how communicative actions are represented in the infant brain, or about the mechanism through which an understanding of communicative actions facilitates word learning. In this chapter, I will present a neural network model of language and cognitive development which addresses both of these questions. The representations of communicative actions that the model learns (which have roughly the form X says that P) encode the propositional content of utterances in a novel way. I also discuss how these representations may serve as developmental precursors for more sophisticated propositional attitude representations such as X believes that P.