Fig. 2
From: Monochromaticity of Orientation Maps in V1 Implies Minimum Variance for Hypercolumn Size
Correlation spectra of orientation maps in macaque and tree shrew V1. a and b are from Niebur and Worgotter’s 1994 paper [33]: in a, the solid and dashed lines are spectra obtained by two different methods (direct measurement of correlations and Fourier analysis) from an experimental map obtained by Blasdel in macaque monkey, the power spectrum of which is displayed on b. Images c and d are from Schnabel’s 2008 thesis [30, p. 104]. Methods for obtaining c and d from measurements on Tree Shrews are explained precisely by Schnabel in [30, Sects. 5.3 and 5.4]. The green- and blue-shaded regions code for bootstrap confidence interval and 5 % significance level, respectively. The power spectrum in d has standard deviation around 0.2 in the unit displayed on the horizontal axis and determined by the location of the maximum; the mean and quadratic wavenumbers in this spectrum are in the intervals \([1.05, 1.10]\) and \([1.18,1.23]\), respectively