Fig. 3. Compressed spectral array: Resting and reading. Processed EEG of frontal and central electrodes from the left and right sides of the head (F3, F4, C3, C4) are shown for two mental states, eyes closed (resting) and reading. The spectral edge is shown as the continuous vertical trace and represents 97% of total power. The frequencies are plotted on the horizontal axis from 0.5 to 20 Hz and power as μV2on the vertical axis. Each trace is 4 s in duration.