Get your mind in the mood for languages. “Last month I stood before my Applied Linguistics class and gave students the accumulated wisdom: If ‘critical period’ means a sharp decline in learning ability, it does not exist. There is simply a progressive decline from birth to death as people mature. Resistance to a new language increases with the maturation of known languages because brain circuitry interprets any new input in terms of the patterns of known languages.…A hand went up.…‘Haven’t you told us that under some circumstances, such as multiple personalities, hypnotism, and unusual patterns of cerebral dominance, adults can muster up new languages with very little constraint by maturational processes?’ She was right. I have said those things.”
Grant Barrett