The Human Ventromedial Prefrontal Cortex: Sulcal Morphology and Its Influence on Functional Organization

Abstract

The ventromedial prefrontal cortex (vmPFC), which comprises several distinct cytoarchitectonic areas, is a key brain region supporting decision-making processes, and it has been shown to be one of the main hubs of the Default Mode Network, a network classically activated during resting state. We here examined the interindividual variability in the vmPFC sulcal morphology in 57 humans (37 females) and demonstrated that the presence/absence of the inferior rostral sulcus and the subgenual intralimbic sulcus influences significantly the sulcal organization of this region. Furthermore, the sulcal organization influences the location of the vmPFC peak of the Default Mode Network, demonstrating that the location of functional activity can be affected by local sulcal patterns. These results are critical for the investigation of the function of the vmPFC and show that taking into account the sulcal variability might be essential to guide the interpretation of neuroimaging studies. SIGNIFICANCE STATEMENT The ventromedial prefrontal cortex (vmPFC) is one of the main hubs of the Default Mode Network and plays a central role in value coding and decision-making. The present study provides a complete description of the interindividual variability of anatomical morphology of this large portion of prefrontal cortex and its relation to functional organization. We have shown that two supplementary medial sulci predominantly determine the organization of the vmPFC, which in turn affects 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.

Spectral partitioning identifies individual heterogeneity in the functional network topography of ventral and anterior medial prefrontal cortex

“…Zoomed-in boxes show areas in PCC and ventral mPFC where the DN community appears to follow sulci. The superior rostral sulcus aligned with the DN community, in agreement with findings by Lopez-Persem et al (2019). B: Correlations between cortical curvature and the unthresholded Fiedler values.…”

“…Figure 8A shows a qualitative comparison between the thresholded DN and non-DN communities and curvature maps for two individuals. In agreement with findings from Lopez-Persem and colleagues (2019), the DN community appeared to overlap with the superior rostral sulcus in vmPFC in these individuals, whereas the non-DN community included both gyri and sulci. A similar trend was observable in left PCC, where the DN community traced sulcal layouts and non-DN was more likely to appear in gyri.…”

“…Several previous studies have provided evidence that sulcal and gyral organization informs the location of functional effects (Amiez & Petrides, 2014; Amiez et al, 2013; Zlatkina et al, 2016). Recent work has suggested that DN regions in individuals lie mostly within sulci in vmPFC (Lopez-Persem et al, 2019). We sought to reproduce this relationship using the SP communities, and interrogated whether it persisted in PCC and more superior mPFC regions.…”

“…Next we asked whether the location of the DN and non-DN communities was systematically related to sulcal morphology. Based on a previous report of individual alignment of DN within sulci in ventral mPFC (vmPFC; Lopez-Persem et al, 2019), we subdivided our search space into three regions: vmPFC, which matched the ROI used by Lopez-Persem and colleagues (2019; areas 25, s32, a24, 10v, 10r, p32, and OFC); superior mPFC (sup-mPFC), encompassing the remaining dorsal areas in our mPFC space; and all of the PCC search space. We used each subject’s curvature maps from the HCP (transformed to fs_LR 32k space), in which cortical depth is quantified by negative numbers for sulci and positive numbers for gyri.…”

“…A recognized limitation of group averaging and meta-analysis is that the functional topography of individual brains can be misaligned and blurred (Fedorenko et al, 2012; Guntupalli et al, 2018; Michalka et al, 2015; Tobyne et al, 2018; Wang et al, 2015; Woo et al, 2014), exaggerating the apparent overlap across domains. This concern is especially pronounced in ventral mPFC, which is subject to considerable idiosyncratic cortical folding (Lopez-Persem et al, 2019; Mackey & Petrides, 2014; Zilles et al, 2013) and inter-subject functional variability (Mueller et al, 2013). An alternative approach is to focus on analyses at the individual-participant level.…”