Published online by Cambridge University Press: 12 August 2005
We commend Arbib for his original proposal that a mirror neuron system may have participated in language origins. However, in our view he proposes a complex evolutionary scenario that could be more parsimonious. We see no necessity to propose a hand-based signing stage as ancestral to vocal communication. The prefrontal system involved in human speech may have its precursors in the monkey's inferior frontal cortical domain, which is responsive to vocalizations and is related to laryngeal control.