Structure and stimulation in the ontogeny of spoken language.

Linguistic innateness is a fundamentally physical notion, which ultimately requires independent physical evidence. For spoken language, it is relevant to consider babbling, components of which are unaffected by ambient stimulation and are predicted by models of vocal tract function. Links between babbling and speech point to innate factors in the ontogeny of spoken language and invite attention to central control mechanisms. These neural capabilities enable oral language learning by providing children with control over an initial stock of speech-like movements and by directing their attention to salient linguistic patterns. Dispositions to attend to some cues are so strong that little stimulation is required. In other cases, predispositions are weak, and acquisition requires correspondingly more experience. To understand the ontogeny of language, we need to learn which cases are which and to know how these interactions occur and change over the course of acquisition.