15 - Specialization for language

Summary

Where is language located in the brain? Is the human brain specialized for language? Are there sensitive periods for acquisition? Is any aspect of language innate? Are there learning mechanisms dedicated to language? Wernicke and Broca identified language areas for comprehension and production in the left hemisphere, and modern studies rely on PET, fMRI, and MEG for tracking just where information is processed. It is unclear whether there is a sensitive period for language acquisition. Evidence from brain injuries and feral children is problematic. Evidence from second language learning is rarely comparable in amount of experience, feedback, and practice to first language. As children acquire more language, they process it faster, with greater left-hemisphere specialization. With bilingualism comes greater density in the left hemisphere. Sign languages are also processed in the left hemisphere. But some aspects of language are processed in the right hemisphere. Language is part of a more general system of communication, with affect, facial expression, gesture, and stance, so storage in the brain occurs in both hemispheres.