EEG-Based Emotion Recognition: A State-of-the-Art Review of Current Trends and Opportunities

Table 2

EEG signals and its frequency bands.

Band name	Frequency band (Hz)	Functions
Delta	<4	Usually associated with the unconscious mind and occurs in deep sleep
Theta	4–7	Usually associated with the subconscious mind and occurs in sleeping and dreaming
Alpha	8–15	Usually associated with a relaxed mental state yet aware and are correlated with brain activation
Beta	16–31	Usually associated with active mind state and occurs during intense focused mental activity
Gamma	>32	Usually associated with intense brain activity