Abstract
Central and peripheral vision have different functions. For example, we regularly attend to objects in central vision, and only occasionally attend to objects in peripheral vision. However, aside for compensating for the cortical magnification factor, neuroscientists tend to treat centrally-and peripherally-responsive cortical areas as if they were the same. We tested how centrally-representing and peripherally-representing parts of primary visual cortex (V1) differed in cortical thickness and functional connectivity. We collected T1-weighted structural MRI data and blood oxygen level dependent functional connectivity MRI data from healthy young adult participants aged 19-30 years. V1 was identified anatomically and segmented into central and peripheral portions using Freesurfer software. Our data imply that central vs. peripheral primary visual cortex have distinct patterns of cortical thickness and functional connectivity. Patterns of cortical thickness and functional connectivity echoed each other, in a way that is consistent with putative functions of central and peripheral regions. Cortex was thicker in central V1 than peripheral V1, consistent with studies showing that increased use leads to increased cortical thickness. Echoing this inhomogeneity of structure, central V1, more than peripheral V1, was functionally connected to several fronto-parietal regions that have been shown by previous studies to be involved with moment-to-moment control. This result is consistent with the idea that central vision often requires moment-to-moment control and therefore centrally-representing cortical areas have developed strong connections to control regions. Another network of regions, termed the “default mode network” has been shown in previous work to be suppressed during tasks requiring externally focused attention. Peripheral V1, more than central V1, was functionally connected to regions of the default mode network. Together, these findings suggest that the anatomy and connections of V1 differ between centrally- and peripherally- representing areas, in a way that is consistent with their function.
Meeting abstract presented at VSS 2015