Frequency tuning of complex cells. We used three different frequency bands. The underlying Gabor filters had logarithmically spaced frequency peaks and their frequency responses overlapped at the -3dB points. Peak spatial frequencies were chosen as follows: f1 = 0.1 cycles/pixel, f2 = 0.21 cycles/pixel and f3 = 0.42 cycles/pixel. The amplitudes of the Fourier Transforms of the odd-symmetric Gabor filters are shown.