Fig. 1
Examples of rate modulation functions and their frequency-domain representations. a A single-peaked function (grey curve in the background) and two double-peaked functions. b Modulus of the Fourier transform of the functions in (a). c Modulus of the Fourier transform of single-peaked rate modulations varying in the parameter τ (1, 2, 4 or 8 ms). d Modulus of the Fourier transform of double-peaked rate modulations with t 2=20 ms, τ 1=τ 2=2 ms, r 1=−1 and r 2 varying in steps of 0.2 from -1 to 1