Population summary of directional discrimination in areas PIVC (red), VIP (green), and MSTd (blue). A, Population tuning curves of the excitatory cells in the horizontal plane (PIVC: n = 120, VIP: n = 66, and MSTd: n = 141). B, Population tuning curves of the inhibitory cells in the horizontal plane (PIVC: n = 8, VIP: n = 18, and MSTd: n = 29). Data have been aligned to the peak (for excitatory cells) or trough (for inhibitory cells) response direction of each cell (0°), and spontaneous activity was subtracted before averaging. C, Comparison of averaged Fisher information in the horizontal plane among three areas. Fisher information was aligned to the preferred azimuth direction of each neuron, which is illustrated here as 0°.