Adjust brainwave power levels to explore how the Pope et al. (1995) engagement index responds. Used in real Brain-Computer Interface (BCI) research to estimate cognitive engagement.
E = β ÷ (α + θ)
Beta rises during active cognition and focused attention.
Alpha + theta rise during rest, drowsiness, and idle states.
Brainwave power controls
Theta4–7 Hz2
Alpha8–12 Hz85
Beta13–30 Hz10
Band power chart
Engagement index
0.11
β / (α + θ)
Alpha / Beta ratio
8.50
higher = more resting
Dominant band
Alpha
relaxed / idle
Low engagement — restingresting
low engagementhigh engagement
Alpha is dominant. The visual cortex is idle — this is the eyes-closed resting state.
Alpha surges over occipital regions when sensory input is absent, a well-documented
idling rhythm of the cortex.
What each band means
Theta 4–7 Hz
Drowsiness, mind-wandering, internal attention. Frontal theta rises with cognitive fatigue and disengagement.
Alpha 8–12 Hz
Brain idle rhythm. Drops when attention engages — called Event-Related Desynchronization (ERD). Strongest at occipital channels.
Beta 13–30 Hz
Active cognition, focused attention, and working memory. Rises during math, reading, and problem-solving tasks.