Table 2.

Frequency bands and associated cognitive states.

Frequency	Band (Hz)	Functional significance
Delta	1–4	Sleep state Arrhythmic delta connected to problem-solving tasks (Niedermeyer and da Silva, 2004)
Theta	4–8	Wakefulness with state of forced attention Creativity Distractibility Inattention (Niedermeyer and da Silva, 2004)
Alpha	8–13	Relaxed wakefulness Meditation Peacefulness (Niedermeyer and da Silva, 2004)
Beta	13–21	Attentive wakefulness Focus Relaxed thinking (Niedermeyer and da Silva, 2004)