Abstract
Primate communication systems are complex and utilize manual gestures and vocalization for the transfer of information. The relationship between these two communicatory media has become increasingly interdependent in apes as specific cerebral regions have gradually assumed a governing role in cognitive communication processes.
Over the course of primate evolution, subcortically processed monkey vocalizations have become largely corticalized and lateralized to the left hemisphere in humans. The emergence of handedness has shifted cortical control over manual gestures to the left hemisphere and established a cerebral specialization subserving gesture and vocalization in higher primates.