Speech and gesture are mediated by independent systems

Abstract

Arbib suggests that language emerged in direct relation to manual gestural communication, that Broca's area participates in producing and imitating gestures, and that emotional facial expressions contributed to gesture-language coevolution. We discuss functional and structural evidence supporting localization of the neuronal modules controlling limb praxis, speech and language, and emotional communication. Current evidence supports completely independent limb praxis and speech/language systems.