Fig. 3: Topographic anisotropy in EVC’s pRF.
a Comparison of the radial (\({\sigma }_{{{{{{\rm{radial}}}}}}-{{{{{\rm{axis}}}}}}}\)) and tangential (\({\sigma }_{{{{{{\rm{tangential}}}}}}-{{{{{\rm{axis}}}}}}}\)) extents of the pRFs defined by the radially oriented gratings (left) and by the tangentially oriented gratings (right). Insets show the across-individual averages of the pRF’s spatial extents for the two stimulus orientation conditions. For illustrative purposes, the pRF topography is centered at the eccentricity of 3° on the horizontal meridian in the right visual field, where the horizontal and vertical widths of the ellipsoids mark the average widths of the pRFs at half maximum in the radial and tangential axes, respectively. Thin gray lines, 29 individuals; Thick colored lines and error bars, mean and 95% CI; Asterisks, statistical significance of two-tailed paired t-test; *p < 0.05, **p < e-03, ***p < e-08; Orange and blue colors, the radial and tangential orientation conditions. b Comparison of the radial bias indices of the pRF anisotropy between the radial, \({{RI}}_{{{{{{\rm{pRF}}}}}}}(\theta ={{{{{\rm{radial}}}}}})\), and tangential, \({{RI}}_{{{{{{\rm{pR}}}}}}F}\left(\theta ={{{{{\rm{tangential}}}}}}\right)\), orientation conditions. The histogram in the upper-right corner of each panel shows the across-individual distribution of differences in RIpRFs between the two orientation conditions. Dots, 29 individuals; Black crosshairs, across-individual means and their standard errors.
