In Fig. \ref{fig_tfr} we can see that before the stimulus onset there is some activity in the alpha band over the posterior parietal cortex. About 100 ms after the stimulus has begun the alpha rhythm is suppressed. There isn’t much activity in other frequency bands or over other locations before or after the stimulus. From Fig. \ref{fig_tfrch2043} we see that there doesn’t seem to be any notable increase in any other frequency band after the stimulus. One can see a small increase in the alpha rhythm about 800 ms after the stimulus. If the measurement was a bit longer we might see alpha rhythm return to the same level as it was before the stimulus. The smaller alpha rhythm at the beginning of the figure might be caused by boundary effects and because the signal is finite in size.