UCL Discovery

Abstract

The human brain exhibits remarkable inter-individual variability in cortical architecture. Despite extensive evidence for the behavioral consequences of such anatomical variability in individual cortical regions, it is unclear whether and how different cortical regions covary in morphology. Using a novel approach that combined non-invasive cortical functional mapping with whole-brain voxel-based morphometric analyses, we investigated the anatomical relationship between the functionally defined retinotopic visual cortices and other cortical structures in healthy humans. We found a striking anti-correlation between the gray matter volume of primary visual cortex and that of anterior prefrontal cortex, independent from individual differences in overall brain size. Notably, this negative correlation formed along anatomically separate pathways, as the dorsal and ventral parts of primary visual cortex showed focal anti-correlation with the dorsolateral and ventromedial parts of anterior prefrontal cortex, respectively. Moreover, a similar inverse correlation was found between primary auditory cortex and anterior prefrontal cortex, but no anatomical relationship was observed between other retinotopic cortices and anterior prefrontal cortex. Together these findings indicate that an anatomical trade-off exists between primary sensory cortices and anterior prefrontal cortex as a possible general principle of human cortical organization. This new discovery challenges the traditional view that the sizes of different brain areas simply scale with overall brain volume, and suggests the existence of shared genetic or developmental factors that contributes to the formation of anatomically and functionally distant cortical regions.