Fig. 3: Conceptual models of pRF size.

Upper row: two conceptual models of V1 that could account for the influence of r-eccentricity on pRF size in the wide-field data. The top left panel shows the position of model cell bodies in V1. The other panels show models in which RF positions are displaced purely by changes in cortical magnification factor (CMF), with lower magnification at higher eccentricities (middle) or by increased RF scatter at larger eccentricities (right). The black lines connected to each RF illustrate the displacement of the RF. Lower row: two equally sized analysis windows were drawn on the cortex, one at the foceal representation (red) and one in the periphery (blue). The RFs of cells within the analysis window are shown colored in the right panels. An estimate of the pRF can be made by taking the convex hull (shaded region) of the RF positions in space. Both the CMF and scattering model result in smaller pRFs at the focea (compare the areas of the red and blue regions).