Published: 9 August 2018 at 22:00
Research finds link between vocal repertoire and relative size of key regions of the brain
New research examining the brains and vocal repertoires of primates offers important insight into the evolution of human speech.
The vocal tract and larynx is similar in form and function amongst virtually all terrestrial mammals, including humans. However, relative to humans, non-human primates produce an extremely limited range of vocalisations.
Published in the journal Frontiers in Neuroscience, the new research investigates whether the reason primates are incapable of producing speech is because they lack the brain mechanisms needed to control and coordinate vocal production.
The study focused on two particular features of the brain: the cortical association areas that govern voluntary control over behaviour; and the brainstem nuclei that are involved in the neural control of muscles responsible for vocal production.
The academics, from Anglia Ruskin University and Stony Brook University, found a positive correlation between the relative size of cortical association areas and the size of the vocal repertoire of primates, which can range from just two call types in pottos to at least 38 different calls made by bonobos.
Lead author Dr Jacob Dunn, Senior Lecturer in Zoology at Anglia Ruskin University, said: