Fig. 4: Phase selectivity as a function of preferred SF (fo).

a Scatter plot compares fo to F1/F0 from three ROIs, each indicated by a different symbol. See Table 2 for joint statistics. Each of the three green curves show the result of pooling from the same population of scale invariant simple cells, and the same retinotopic integration window (σh(x) = 0.24°; determined in Fig. 3), but with different alignment in the absolute phase. The solid green curve is the least-squares fit of phase alignment to the data. To the left of the y-axis are phase tuning curves (black) and fits (gray) of four example neurons in one ROI outlined and enumerated in e. b Like the scatter plot in a, y-axis data points are F1/F0. However, the x-axis is converted into a metric for the deviation from scale invariance. Specifically, it is the measured RF width divided by the scale invariance prediction of RF width. To obtain the domain of the green curve, we took the following ratio: pooled scale invariance prediction of RF width (Eq. (5)) over the scale invariance prediction of RF width (Eq. (1)). Gabor insets illustrate how the number of ON/OFF subfields increase along the x-axis. c Simulation of the pooling model in the spatial domain at fo = 2 cyc/°, for the three examples of phase alignment plotted in a (see green open circles in a). At bottom in blue are the 1D Gabor functions from the model of scale invariance. The spatial phase progresses at a different rate, inside each of the three green rectangles. In the left example, “relative phase” does not change, whereas in the right example “absolute phase” does not change. Just above, also in blue, are the Gabor functions weighted according to the Gaussian in the pooling model (σh(x) = 0.24°). The top green curves are the superposition of scale invariant inputs, where the constant absolute phase (right) yields the greatest phase modulation. d Maps of F1/F0. Bottom panel is all simple cells (F1/F0 = π) and is the input to the scale invariant pooling model. Top panel is the output of scale invariant pooling, based on the solid green fit to the data in a. e Measured map of F1/F0. f Pearson correlation coefficient between neuronal pairs, within 75 μm cortical distance bins, using all three ROIs in the study. The symbol at each distance bin indicates the correlation coefficient’s significance: Closed dot is p > 0.01, asterisk is p < 0.01, asterisk and open circle is p < 0.001.