Where is the language acquisition device in the brain

No specific claim was made regarding the specific location of the LAD in the brain. In , Lenneberg published the book Biological Foundations of Language, in which he argued that humans are biologically capable of learning language only until puberty. After puberty, humans are biologically unable to master the intricacies of natural language. For many years, researchers in zoology had recognized the existence of critical periods of development for a range of nonhuman animal species, such as songbirds, ducklings, horses, dogs, and sheep.

Case studies of children raised without sufficient exposure to human language appeared to support the critical period hypothesis. Such individuals, such as Victor, the wild child, and Genie, had not been able to master the grammatical intricacies of sentence construction. Individuals born with severe hearing loss who were not exposed to a signed language until after puberty typically had not been able to achieve nativelike proficiency.

Furthermore, there was ample anecdotal evidence that individuals who attempt to learn a second language after puberty rarely achieve a level of proficiency comparable to that of one who learns the language during childhood. Some researchers have rejected the notion that language acquisition is aided by innate knowledge. In , the behaviorist B. Skinner published the book Verbal Behavior, in which he argued that all types of language behavior were learned after birth through the same learning processes that are used for all human learning.

This theory of a congenital basis for formulating language, regardless of the native language spoken around the infant, has been hotly criticized by behaviorists and others who favor the notion that environment and nurturing are responsible for language acquisition. The LAD theory posits that a set list of acceptable sentence structures — that is, possible combinations of subjects, verbs , objects, and modifiers — are known to children at birth.

Though children rarely perfect grammar spoken during their early years, the LAD theory argues that with the sentence fragments and run on sentences of ordinary human speech and the innate universal grammar rules, children are able to flesh out a full language in just a few short years.

According to the LAD theory, a child does not pass its early years just meaninglessly repeating words and phrases, but in observing grammar variations and supplemental rules to construct new variations on sentence structure.

The language acquisition device theory was first introduced in the s. Noam Chomsky tied it into the nativist theory of language, which proposed that humans have an inborn capacity or instinct to aid in acquiring their mother tongues. This went in opposition to the behaviorist theories of learning set forth by B. Skinner, which allowed for no such biological instincts in the human species. To build on nativist theories, Chomsky asserted all people must utilize the LAD to acquire language.