Core language network separated from other networks during primate evolution

The evolution of language in humans, in contrast to communicative systems in other primate species is hotly debated. Now, thanks to the study of brain connectivity between different primate species and by adopting a framework proposed for segregating functional language and communication activation in humans, Angela Friederici and Yannick Becker from MPI CBS argue in a recent correspondence article in Nature Reviews Neuroscience that the core language network can be neurally separated from other communication-relevant networks during primate evolution.
 

The core language network consists of Brodmann area (BA44) and the posterior temporal cortex connected via a fiber tract called the arcuate fascile which guarantees the linguistic information flow between these regions. An additional perceptual-motor network which guarantees the link between the core language system and the external world during language production and perception involves BA6 in the premotor cortex and the auditory cortex in the superior temporal gyrus (STG).

“While the perceptual-motor network is present in the monkey, the chimpanzee and the human brain, the arcuate fascile as part of the core language network only shows a strong extension to the middle temporal gyrus (MTG) in the human brain.”, explains Angela Friederici. “This suggests that this extension to the MTG is of particular relevance for the evolution of human language.”