Figure 9From: Distinguishing low frequency oscillations within the 1/f spectral behaviour of electromagnetic brain signalsTime domain signal consisting of 2 sine waves at 0.1 Hz and 0.5 Hz of varying SNR (SNR1 and SNR2 respectively) filtered through the differentiator and their corresponding spectra before and after filtering. (a) SNR1 is less than SNR2, (c) SNR1 is approximately twice SNR2, (e) SNR1 is much higher than SNR2; (b), (d) and (f) show the corresponding spectra.Back to article page