“…EEG power spectra are typically examined through frequency range consisting of delta (0.5-4 Hz), theta (4-8 Hz), alpha (8-13 Hz), and beta (13-30 Hz) [15][16][17]. An alpha frequency range is considered relevant to a feeling of relaxation without attention whereas beta power is related to the activation of the brain in active processing when on task [15,16,18,19]. The theta rhythm is brought on by early drowsiness or in a state of deep meditation [17,18] while the delta rhythm has been associated with the absence of consciousness or seen in the state of deep sleep [18,19].…”