Regarding the electrodes on the right side of the subject’s scalp, it was possible to note from the results in figure \ref{fig:beta} that AF4, F2, F4 and FFC4 channels showed a decrease in the amplitude of frequencies from 20 Hz up to 24 Hz for the mean of the task blocks. This was particularly strong at the 24 Hz frequency. All electrodes, except for AF4 and FFC4 channels, had a very well defined and appreciable peak at 16 Hz for task blocks, and these other two channels contained a big peak at about 21 Hz. AF4 particularly, also had a big peak at 28 Hz for the task blocks. In general, all the electrodes positioned on the right side of the scalp displayed noticeable frequency peaks close to 16 Hz, 18 Hz and 21 Hz for task blocks.

For the mean signal of the task blocks, electrodes on the left side of the scalp also showed a very similar behavior regarding the 24 Hz frequency: a decrease in the amplitude. Futhermore, AF3 and F channels had a very well defined peak at 25 Hz. Except for the FC3 electrode, all others presented a decrease in the amplitude at 17 Hz and 19 Hz when compared to the rest blocks. FC1 is in particular an electrode that can be very distinguishable from the others: it contained clear differences between blocks at 15 Hz, 17 Hz, 19.5 Hz, 22 Hz and 27.5 Hz. F3 and F5 electrodes had a very well defined peak at about 24.5 Hz. Besides, FFC3 showed a peak that is decreased in amplitude when comparing to rest blocks at 16 Hz.

The occipital electrode (Oz) presented a very big peak at 26.5 Hz during tasks. This peak was much lower in amplitude during the rest blocks.