How Localized are Language Brain Areas? A Review of Brodmann Areas Involvement in Oral Language

The interest in understanding how language is localized in the brain has existed for centuries. Departing from seven meta-analytic studies of functional magnetic resonance imaging activity during the performance of different language activities, it is proposed here that there are two different language networks in the brain: first, a language reception/understanding system, including a core Wernicke's area involved in word recognition (BA21, BA22, BA41, and BA42), and a fringe or peripheral area (extended Wernicke's area: BA20, BA37, BA38, BA39, and BA40) involved in language associations (associating words with other information); second, a language production system ( Broca's complex: BA44, BA45, and also BA46, BA47, partially BA6-mainly its mesial supplementary motor area-and extending toward the basal ganglia and the thalamus). This paper additionally proposes that the insula (BA13) plays a certain coordinating role in interconnecting these two brain language systems.