Fig. 6

Change of power ratio with recording time. Power ratio are calculated from the power spectrum obtained from FFT analyses of the EEG of dolphin with the movement listed in Table 1 as recording No. 1 (1), No. 2 (2), No. 3 (3), No. 4-1 (4-1), No. 4-2 (4-2), No. 5-1 (5-1), and No. 5-2 (5-2). The FFT conditions were as follows: interval, 2.048 s; window function, hamming; overlap, 1/2; spectrum, power and frequency resolution, 0.488 Hz; the number of FFT points, 76 (1), 140 (2), 251 (3), 112 (4-1), 100 (4-2), 96 (5-1), 65 (5-2)