Supplementary Figure 7: Eccentricity mapping.

a, Spatial distribution of the responses to the eccentricity stimulus within both hemispheres (left hemisphere, top; right hemisphere, bottom) of M2. The left panel of each row shows in blue-cyan the responses that were greater to the foveal disc (1.5°) than to the other eccentricity stimuli combined. In the response maps, the spot of orange-red within the annulus of cyan corresponds to the fixation spot. The subsequent panels show responses to progressively expanding annuli (the radii of the annuli is given). The stimulus comprised a checkerboard of colors defined by the L-M axis and one defined by the S-axis. Note that progressively expanding annuli elicit correspondingly wider annuli of activation within the cortex, as shown by others (e.g. Fize et al, 2003). In addition, along IT is evident clear activation to the central disc and smallest annulus. b, the left panel shows the activation pattern comparing the first two eccentricity conditions with the last two (and is what is reported in Figure 6). For comparison, the right panel shows the results of the meridian mapping experiment. Along IT is shown higher activation to stimulation along the vertical meridian at locations in between the central visual field representations. We do not interpret these as vertical meridian representations, but rather as indication of a peripheral bias: the vertical meridian stimulus comprised 60° wedges, while the horizontal meridian stimulus was 30°. Thus on average, the vertical stimulus represented more activation of the peripheral visual field.