Neuro-anatomy and functional connectivity of the Orbito-medial prefrontal cortex
Between 2017 and 2020, during my post-doc with Jérôme Sallet at the University of Oxford, I investigated the neuro-anatomy and functional connectivity of the orbito-medial prefrontal cortex, known as the main hub of the Brain Valuation System.
Value-based decision-making relies on brain networks of the prefrontal cortex, especially the ventro-medial prefrontal cortex (vmPFC) and the orbitofrontal cortex (OFC). Despite the fact that brain structures constrain brain functions, the anatomo-functional organization of the vmPFC and OFC is still poorly understood. In my post-doctoral project, I used anatomical, functional and resting-state MRI (aMRI, fMRI and rs-MRI) to identify the intrinsic organization of these regions based on connectivity pattern analysis in humans but also in primates.
Individual variability in frontal sulci
In Lopez-Persem et al., Journal of Neuroscience, 2019, we provide a complete description of the inter-individual variability of anatomical morphology of the human vmPFC its relation to functional organization. We have shown that two supplementary medial sulci predominantly determine the organization of the vmPFC, which in turn affect the location of the functional peak of activity in this region. Those results show that taking into account the variability in sulcal patterns might be essential to guide the interpretation of neuroimaging studies of the human brain and of the vmPFC in particular.
Functional asymmetry in the OFC
Lateralization of functions in the brain has been demonstrated in many different cognitive processes. It is supposed to increase processing abilities by reducing bilateral redundancy. Yet, lateralization of reward processing, despite extremely common asymmetrical findings, has received little attention. In Lopez-Persem et al., PNAS 2020, we found a functional lateralization of the response to reward in the lateral part of the orbitofrontal cortex (OFC), together with an asymmetric functional connectivity pattern. This particular feature was not only identified in humans but also in non-human primates. Our findings challenge the classical view of the OFC as a symmetrical brain region. They are urging the need for considering the specific contribution of the left and right OFC when investigating reward-related signals.
