Speakers > Céline Amiez
Stem-cell and Brain Research Institute in Lyon, France
Celine Amiez is Director of research at the Stem-cell and Brain Research Institute in Lyon, France. She joined the team of Emanuel Procyk in 2010 and continues to closely collaborate with M. Petrides from MNI in Montreal where she worked for seven years after her PhD. Celine's work aims to understand how brains produce complex behavior and how these systems have evolved through primate evolution. These systems are assessed using a unique combination of neuroimaging methods in primates and subject-by-subject analysis, which gives access to the most precise level of the anatomo-functional organization of the cerebral cortex.
Sulcal variability identifies differential evolution of prefrontal cortical regions in primates
Although the relative expansion of the frontal cortex in primate evolution is generally accepted, the nature of its scaling and inter-species anatomo-functional comparisons of the frontal areas remain controversial. Indeed, a large literature has emphasized the link between the extent of gyrification, the rapid expansion of the cerebral cortex, and the complexity of the computational processing performed in a given brain. Although important, these discussions of cortical gyrification have not considered another major dimension of sulcal pattern organization, i.e. its variability. I present here results showing how the medial and the lateral frontal cortical sulcal organization has evolved through the primate order. By performing within- and across-species comparison of sulcal morphological variability based on neuroimaging anatomical scans, I provide evidences that both regions are comparable anatomically and functionally from Old World monkeys to Hominoidea, at the sole exception of the ventrolateral prefrontal cortex. In this latter region, although chimpanzees display the precursor of the human ascending sulcus rostrally limiting Broca’s area (Area 44), this precursor does not join the insula as in human. This lack of opercularization prevents the formation of the frontal operculum, and consequently prevents the formation of the sulci featuring the pars triangularis and therefore the formation of a full Broca’s complex. These discoveries, together with recent paleontological studies suggesting that the frontal operculum appears only in Neanderthals concomitantly with modern language abilities suggests that the frontal operculum might be key to support language functions. |
