Theta/Beta at Cz
EEG theta (low frequency of 4-8 Hz in a state of deep relaxation, meditation, imagery with good/creative ideas.) and beta (high frequency of 13-21 Hz and in a state of awake, actively engaged in mental activities) waves are associated with cortical arousal, which increases wakefulness, vigilance, muscle tone, heart rate, and minute ventilation of the brain. The theta and beta brain waves recorded from an EEG scan shows the balance struck between logical/rational and creative/intuitive processing.
Theta/beta ratios associated with cortical arousal, measuring Cz channel placement on the EEG, and high theta/beta ratios have been shown to consistently differentiate between ADHD and normal samples, with meta-analyses showing up to 94% sensitivity and specificity. The theta/beta ratio trait may arise with other conditions, and with some medication as well and so this non-specific measure is included in the sports report because some researchers want to screen for changes in state, medications, or for pre-existing conditions while investigating trauma management.