EEG Feature Extraction and Data Augmentation in Emotion Recognition

Table 3

EEG Frequency band.

Frequency	Frequency range	Description	Occurrence
Delta	Delta <4/5	Delta frequency band waves have the highest amplitude and the lowest frequency.	It is a wave shape that appears in a relaxed state like deep and unconscious sleep. It describes a person in a state of anesthesia and unconsciousness. Similar EEG frequencies appear in epileptic seizures, loss of consciousness, and some coma states.
Theta	3/5 < theta <7/5	Theta frequency band waves are a fast irregular activity.	Theta waves are associated with natural consciousness or thinking and anxiety and concentration. Beta is usually seen with a symmetrical distribution on both sides of the brain but is more pronounced in the frontal lobe. It may not be present or reduced in areas where the cortex is damaged.
Alpha	7/5 < alpha <13	Alpha frequency band waves are generated by the simultaneous electrical activity of large groups of neurons.	They are usually found with the eyes closed but still awake in signals recorded from the scalp more than the occipital lobe during periods of relaxation. Open eyes also reduce drowsiness and sleepiness. It mostly indicates a state of consciousness
Beta	12 < beta <25	Beta frequency band waves are a fast irregular activity, where the cortex is damaged.	Beta waves are associated with natural consciousness or thinking and anxiety and concentration. Beta usually occurs on both sides of the brain with a symmetrical distribution but is mainly seen in the frontal lobe. It may not be present or reduced in areas
Gamma	26 < gamma <70	Gamma waves are thought to be a sign of the active exchange of information between the cerebral cortex and other areas.	Gamma waves are usually generated in the brain when people are conscious and when the eyes move rapidly. Gamma and beta waves may overlap within the range of natural frequencies, and the exact boundary between these two frequency bands is not clear and yet is a judgment for experts.