Abstract
Well before their first birthday, babies can acquire knowledge of serial order relations (Saffran et al., 1996a), as well as knowledge of more abstract rule-based structural relations (Marcus et al., 1999) between neighbouring speech sounds within 2 minutes of exposure. These early learners can likewise acquire knowledge of rhythmic or temporal structure of a new language within 5-10 minutes of exposure (Nazzi et al., 1998). All three of these types of knowledge likely play invaluable roles in "bootstrapping" language acquisition. Two important open questions that remain include: What are the mechanisms that provide this rapid learning ability, and how do they depend on pre-exposure to the environment? Here we show that a neurophysiologically validated temporal recurrent network simulates babies' capabilities to learn serial order and rhythmic structure. Indeed the recurrent network is capable of representing serial and temporal structure with no pre-exposure, and through exposure these internal representations can become bound to behavioural responses. In contrast, babies' performance in extracting abstract structure can only be simulated by a modified version of the model. We thus demonstrate how innate representational capabilities for serial and temporal structure of language could arise from a common neural architecture, distinct from that required for the representation of abstract structure, and we provide a predictive testable model of at least these aspects of the initial computational state of the language learner.