Lamendella's Neurofunctional theory of second language acquisition (1979) states that the acquisition of second and foreign languages is mainly the product of neural (brain-based) processes. In turn, the neurofunctional activity is also based on sub-processes which take charge of specific pieces of the language itself.
According to the theory, language functioning is dependant on brain activity, particularly on the left hemisphere of the brain. The areas associated with language learning are identified as the Wernicke's area and the Broca area.The areas of Wernicke and Broca process the information that leads to comprehension and final production of language.
The theory also touches on research that shows that the right side of the brain is in charge of processing language holistically, that is, in a more generalized and universal way. This side of the brain recognizes patterns in speech and intonation that are reinforced by constant exposure to the second language.
Lamendella argues that formulaic speech and fossilization, among other aspects of second language acquisition are processes that primarily occur in the brain as a natural function. Hence, the Neurofunctional theory of linguistics is founded on the biological and neural aspects of acquisition, and not in a behavioral or merely developmentally cognitive approach.
The theory further offers that language acquisition is done in a primary and secondary manner. The secondary manner refers to SLA. Depending on which neurological process takes place, different aspect of of the L2 will be acquired accordingly. There is a list of sub-processes, or hierarchies, which work together to achieve the final product. One of these hierarchies is the communication hierarchy, which consists on all the sub-processes taking place during interpersonal communication to include monitor language usage. The other hierarchy is the cognitive hierarchy , or the combination of sub-processes that analyze and synthesize information. The latter is highly influential in acquiring language because it is through comprehension that it can actually be applied.
In contrast to other theories, Lamendella's Neurofunctional theory is one of the few that reaffirms SLA as a mainly brain-based process that, with enough exposure and opportunity for application, can be achieved by just about anybody.