Abstract
Visual field maps cover a large fraction of the cortical surface, and can be measured using fMRI retinotopic mapping procedures (Engel et al., 1997, Cereb Cortex 7:181). One of the datasets collected in the Human Connectome Project (Van Essen et al., 2013, NeuroImage 80:62) consisted of scanning 183 human subjects in a retinotopic mapping experiment using high-field (7T) fMRI. Here, we describe the experimental paradigm and provide results of population receptive field (pRF) analyses of these data. Our analyses include both pRF results from individual subjects as well as those obtained after averaging fMRI time-series across subjects at anatomically-aligned locations on the cortical surface and in subcortex. The group-average results reveal robust visually-driven signals across much of the brain, including occipital, temporal, parietal, and frontal cortex as well as subcortical areas. Based on these results, we construct a new atlas of retinotopic organization for early visual areas, improving on a previous atlas developed from a smaller set of subjects (Benson et al., 2014, PLoS Comput Biol 10:e1003538). The atlas includes pRF position (polar angle and eccentricity) as well as pRF size, which marks a novel contribution to the field. We will be publicly releasing the new retinotopic atlas and the complete pRF results for the group-average and all individual subjects. We believe these resources will be of great interest to the vision community for several reasons. First, the group-average data and atlas predictions can be used to accurately estimate a subject's retinotopic organization based on their cortical anatomy alone. Second, the dataset serves as a state-of-the-art characterization of baseline retinotopy measurements in neuro-typical subjects. Finally, this dataset enables characterization of individual differences in retinotopic organization throughout cortex on a scale that has been previously impossible.
Meeting abstract presented at VSS 2018