Abstract

Many animals are not thought to be able to combine their vocalizations into structured sequences, as do songbirds, humans and a few other species. Nonetheless, it remains possible that a number of animals are able to recognize certain types of ordering relationships in sequences generated by ‘artificial grammars’. In this lecture, I aim to explore how understanding the extent of these hidden sequence learning abilities in nonhuman animals could help us to unravel the origins of language and be useful for neurobiological pursuits. I first overview some of our behavioral results with structured sequence processing in three species of primates: marmosets, macaques and humans. I then describe fMRI results identifying the brain regions in macaques that are involved in these forms of sequence processing and compare the macaque results to observations obtained with fMRI in humans using the same paradigm. Finally, I will show data from comparative direct recordings in the human and monkey brain processing the sequences, revealing intriguing neuronal dynamics in auditory cortex, some of which are strikingly similar across the species. Overall, our results reveal that non-human primates appear to possess an evolutionarily conserved perisylvian network involved in the processing of structured auditory input. Alongside the commonalities, there are also indications of cross-species differences that provide hints on how the human brain differentiated to support language.