Figure 9.
Spatial overlap between the scotopically driven activity and thin- versus thick-type columns. In each panel, the Y-axis shows topographical overlap between the fMRI activity in response to scotopic stimuli (relative to spatially uniform gray display of equal scotopic luminance) and thick- (green) versus thin-type (red) columns, in three extrastriate areas: V2 (left panel), V3 (middle panel), and V4 (right panel). For each subject, the level of spatial overlap is normalized by calculating the percentage ratio between the number of overlapping vertices in intact versus randomly shuffled maps (see Methods). The X-axis shows the level of overlap across different threshold levels. In all three areas, scotopically driven activity preferentially overlapped thick-type (relative to thin-type) columns, at thresholds of P < 10−5 and increasingly through the highest threshold that could be reliably measured (P < 10−10). Error bars represent one standard error of mean.