First Language Acquisition

What are the biological underpinnings of language? To what extent are we, as humans, specialized for language? And just what do we mean by specialization here: Existing capacities in the service of language? Capacities unique to language? Specialized organs for language? Specific areas of the brain for the processing of linguistic information? Answering these questions turns out to be complicated. There are extensive behavioral observations of language use and acquisition, but much less firm data available on the neurological underpinnings of language. And still less is known about just how the behavioral data map onto areas of the brain.

The first issue, then, is whether there is specialization of the brain for language. Are there language skills assigned to specific areas of the brain – and if so, which areas and which skills? Such specialization could be present from birth, or the relevant areas might become assigned in the course of development. In either case, exposure to a language would appear essential for learning, but whether we store multiple languages in the same area of the brain or whether the area assigned depends on when during development that language is acquired remains unclear. All of language could be stored in a single area, or different languages or different aspects of a language could be distributed across different areas.

Second, are there sensitive periods during development for the acquisition of a language? Children may need to be exposed to a language before a particular age or stage of development in order to be able to learn it. But things can go awry, so if children are not exposed to language at the right time, do they fail to learn language? Finding out what disrupts normal acquisition and how certain disruptions affect language learning could add to what we know about specialization for language.

Some researchers have appealed to an innate language capacity – innate linguistic categories plus a specialized built-in “language acquisition device.” The assumption is that such a device must exist to account for the speed and universality of acquisition in normal children. Two assumptions – that children acquire all the major syntactic structures of their language very early (by age four in most accounts) and that all (normal) children acquire language – are common to variations on this position.