Electroencephalography (EEG) EEG before treatment will be used to examine mean absolute spectral power within 5 frequency bands. The mean absolute power (in squared microvolts per hertz) will then be computed within the following 5 frequency bands: delta (0.5-3.5 Hz), theta (3.5-7.5 Hz); alpha (7.5-12.5 Hz); beta 1 (12.5-20.5 Hz), and beta 2 (20.5-32.5 Hz). EEG activation / spectral power will be assessed at rest (eyes open and closed) and during cognitive engagement in several tasks.